Z8F2480SH020EG

High-Performance 8-Bit Microcontrollers Z8 Encore! XP® F1680 Series Product Specification PS025016-1013 PRELIMINARY Copyright ©2013 Zilog®, Inc. All rights reserved. www.zilog.com Z8 Encore! XP® F1680 Series Product Specification ii Warning: DO NOT USE THIS PRODUCT IN LIFE SUPPORT SYSTEMS. LIFE SUPPORT POLICY ZILOG’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS PRIOR WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL COUNSEL OF ZILOG CORPORATION. As used herein Life support devices or systems are devices which (a) are intended for surgical implant into the body, or (b) support or sustain life and whose failure to perform when properly used in accordance with instructions for use provided in the labeling can be reasonably expected to result in a significant injury to the user. A critical component is any component in a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system or to affect its safety or effectiveness. Document Disclaimer ©2013 Zilog, Inc. All rights reserved. Information in this publication concerning the devices, applications, or technology described is intended to suggest possible uses and may be superseded. ZILOG, INC. DOES NOT ASSUME LIABILITY FOR OR PROVIDE A REPRESENTATION OF ACCURACY OF THE INFORMATION, DEVICES, OR TECHNOLOGY DESCRIBED IN THIS DOCUMENT. ZILOG ALSO DOES NOT ASSUME LIABILITY FOR INTELLECTUAL PROPERTY INFRINGEMENT RELATED IN ANY MANNER TO USE OF INFORMATION, DEVICES, OR TECHNOLOGY DESCRIBED HEREIN OR OTHERWISE. The information contained within this document has been verified according to the general principles of electrical and mechanical engineering. Z8, Z8 Encore!, Z8 Encore! XP and Z8 Encore! MC are trademarks or registered trademarks of Zilog, Inc. All other product or service names are the property of their respective owners. PS025016-1013 PRELIMINARY Z8 Encore! XP® F1680 Series Product Specification iii Revision History Each instance in the Revision History table below reflects a change to this document from its previous version. For more details, click the appropriate links in the table. Revision  Level Description Page Oct 2013 16 Added a clarification as to when the TOUT timer is available for use. 106 Dec 2012 15 Added Timer Clock Source footnote to the TxCTS2 Register. 117 Nov 2012 14 In the Multi-Channel Timer chapter, corrected/ clarified instances of the TInA–TInD and TOutA– TOutD to T4CHA–T4CHD GPIO pins to more accurately address their relationship to TIN. 120 Oct 2011 13 Revised Flash Sector Protect Register descriptions per CR 13212; revised Packaging chapter. 274, 371 May 2011 12 Correction to Trim Bit Address 0001h Register per CR 13091. 283 Oct 2010 11 Comparator 1 Control Register (CMP1) address formerly showed F90h; now corrected to F91h. 258 Sep 2010 10 Removed references to LSBF bit in Master-In/Slave- 199, 207 Out, Master-Out/Slave-In and SPI Master Operation sections. Aug 2010 09 Changed the frequency for the Internal Precision RC 316 Oscillator from 1.3842 to 1.3824 in Table 168 per CR 12961. Jun 2008 08 Updated Trim Option Bits at 0005H (TVREF). 287 Mar 2008 07 Updated Operation of the On-Chip Debugger Interface and Ordering Information sections. Added Target OCD Connector Interface. 296 Date PS025016-1013 PRELIMINARY Revision History Z8 Encore! XP® F1680 Series Product Specification iv Date PS025016-1013 Revision  Level Description Page Oct 2007 06 Updated Trim Bit Address Description, Trim Bit Address 0007H, Trim Bit Address 0008H, DC Characteristics, Supply Current Characteristics, VDD Versus Maximum System Clock Frequency, Watchdog Timer Electrical Characteristics and Timing, Analog-to-Digital Converter Electrical Characteristics and Timing, Comparator Electrical Characteristics, Low Power Operational Amplifier Characteristics, IPO Electrical Characteristics and Low Voltage Detect Electrical Characteristics. Added Figure 73. 282, 288, 288, 350, 352, 356, 357, 359, 360, 361 Sep 2007 05 Updated Supply Current Characteristics. 352 Aug 2007 04 Changed description of Z8F16800144ZCOG to Z8 Encore! XP Dual 44-pin F1680 Series Development Kit. Updated electrical characteristics in Table 189, Table 190, Table 192, Table 193, Table 195, Table 196. Removed VBO_Trim section and table. 350, 352, 358, 359, 360, 374 PRELIMINARY Revision History Z8 Encore! XP® F1680 Series Product Specification v Table of Contents Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .iii List of Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xv List of Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .xviii Chapter 1. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.1. Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.2. Part Selection Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.3. Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4. An Overview of the eZ8 CPU and its Peripherals . . . . . . . . . . . . . . . . . . . . . . 1.4.1. General-Purpose Input/Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4.2. Flash Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4.3. Non-Volatile Data Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4.4. Internal Precision Oscillator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4.5. Crystal Oscillator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4.6. Secondary Oscillator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4.7. 10-Bit Analog-to-Digital Converter . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4.8. Low-Power Operational Amplifier . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4.9. Analog Comparator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4.10. Temperature Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4.11. Low-Voltage Detector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4.12. Enhanced SPI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4.13. UART with LIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4.14. Master/Slave I2C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4.15. Timers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4.16. Multi-Channel Timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4.17. Interrupt Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4.18. Reset Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4.19. On-Chip Debugger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4.20. Direct LED Drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.5. Acronyms and Expansions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Chapter 2. Pin Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1. Available Packages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2. Pin Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3. Signal Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.4. Pin Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . PS025016-1013 PRELIMINARY 1 1 2 3 4 4 4 5 5 5 5 5 5 5 6 6 6 6 6 6 7 7 7 7 7 8 10 10 10 14 17 Table of Contents Z8 Encore! XP® F1680 Series Product Specification vi Chapter 3. Address Space . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.1. Register File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.2. Program Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.3. Data Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.4. Flash Information Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 19 20 21 21 Chapter 4. Register Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 PS025016-1013 Chapter 5. Reset, Stop Mode Recovery and Low-Voltage Detection . . . . . . . . . . . . . . 5.1. Reset Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.2. Reset Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.2.1. Power-On Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.2.2. Voltage Brown-Out Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.2.3. Watchdog Timer Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.2.4. External Reset Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.2.5. External Reset Indicator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.2.6. On-Chip Debugger Initiated Reset . . . . . . . . . . . . . . . . . . . . . . . . . . 5.3. Stop Mode Recovery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.3.1. Stop Mode Recovery Using Watchdog Timer Time-Out . . . . . . . . . 5.3.2. Stop Mode Recovery Using Timer Interrupt . . . . . . . . . . . . . . . . . . 5.3.3. Stop Mode Recovery Using Comparator Interrupt . . . . . . . . . . . . . . 5.3.4. Stop Mode Recovery Using GPIO Port Pin Transition . . . . . . . . . . 5.3.5. Stop Mode Recovery Using External RESET Pin . . . . . . . . . . . . . . 5.4. Low-Voltage Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.5. Reset Register Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 31 33 34 35 36 37 37 37 37 38 38 39 39 39 39 40 Chapter 6. Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.1. STOP Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.2. HALT Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.3. Peripheral-Level Power Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.4. Power Control Register Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 42 43 43 44 Chapter 7. General-Purpose Input/Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.1. GPIO Port Availability by Device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.2. Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.3. GPIO Alternate Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.4. Direct LED Drive . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.5. Shared Reset Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.6. Crystal Oscillator Override . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.7. 32 kHz Secondary Oscillator Override . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 46 47 47 48 48 48 48 PRELIMINARY Table of Contents Z8 Encore! XP® F1680 Series Product Specification vii 7.8. 7.9. 7.10. 7.11. 5 V Tolerance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . External Clock Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GPIO Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . GPIO Control Register Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.11.1. Port A–E Address Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.11.2. Port A–E Control Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.11.3. Port A–E Data Direction Subregisters . . . . . . . . . . . . . . . . . . . . . . . 7.11.4. Port A–E Alternate Function Subregisters . . . . . . . . . . . . . . . . . . . . 7.11.5. Port A–E Output Control Subregisters . . . . . . . . . . . . . . . . . . . . . . . 7.11.6. Port A–E High Drive Enable Subregisters . . . . . . . . . . . . . . . . . . . . 7.11.7. Port A–E Stop Mode Recovery Source Enable Subregisters . . . . . . 7.11.8. Port A–E Pull-up Enable Subregisters . . . . . . . . . . . . . . . . . . . . . . . 7.11.9. Port A–E Alternate Function Set 1 Subregisters . . . . . . . . . . . . . . . 7.11.10.Port A–E Alternate Function Set 2 Subregisters . . . . . . . . . . . . . . . 7.11.11.Port A–E Input Data Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.11.12.Port A–E Output Data Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.11.13.LED Drive Enable Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.11.14.LED Drive Level Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 49 58 58 59 60 60 61 62 62 63 63 64 64 65 66 66 67 Chapter 8. Interrupt Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.1. Interrupt Vector Listing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.2. Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.3. Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.3.1. Master Interrupt Enable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.3.2. Interrupt Vectors and Priority . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.3.3. Interrupt Assertion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.3.4. Software Interrupt Assertion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.4. Interrupt Control Register Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.4.1. Interrupt Request 0 Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.4.2. Interrupt Request 1 Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.4.3. Interrupt Request 2 Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.4.4. IRQ0 Enable High and Low Bit Registers . . . . . . . . . . . . . . . . . . . . 8.4.5. IRQ1 Enable High and Low Bit Registers . . . . . . . . . . . . . . . . . . . . 8.4.6. IRQ2 Enable High and Low Bit Registers . . . . . . . . . . . . . . . . . . . . 8.4.7. Interrupt Edge Select Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.4.8. Shared Interrupt Select Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.4.9. Interrupt Control Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 68 70 70 70 71 71 72 72 73 74 75 76 77 79 82 82 83 Chapter 9. Timers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84 9.1. Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 9.2. Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 PS025016-1013 PRELIMINARY Table of Contents Z8 Encore! XP® F1680 Series Product Specification viii 9.3. 9.2.1. Timer Clock Source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 9.2.2. Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 9.2.3. Timer Operating Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 9.2.4. Reading the Timer Count Values . . . . . . . . . . . . . . . . . . . . . . . . . . 106 9.2.5. Timer Output Signal Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . 106 9.2.6. Timer Noise Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106 9.2.7. Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106 Timer Control Register Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108 9.3.1. Timer 0–2 High and Low Byte Registers . . . . . . . . . . . . . . . . . . . . 109 9.3.2. Timer Reload High and Low Byte Registers . . . . . . . . . . . . . . . . . 109 9.3.3. Timer 0–2 PWM0 High and Low Byte Registers . . . . . . . . . . . . . . 110 9.3.4. Timer 0–2 PWM1 High and Low Byte Registers . . . . . . . . . . . . . . 111 9.3.5. Timer 0–2 Control Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112 9.3.6. Timer 0–2 Status Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118 9.3.7. Timer 0–2 Noise Filter Control Register . . . . . . . . . . . . . . . . . . . . 119 Chapter 10. Multi-Channel Timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.1. Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.2. Timer Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.2.1. Multi-Channel Timer Counter . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.2.2. Clock Source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.2.3. Multi-Channel Timer Clock Prescaler . . . . . . . . . . . . . . . . . . . . . . 10.2.4. Multi-Channel Timer Start . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.2.5. Multi-Channel Timer Mode Control . . . . . . . . . . . . . . . . . . . . . . . . 10.2.6. Count Modulo Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.2.7. Count Up/Down Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.3. Capture/Compare Channel Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.3.1. One-Shot Compare Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.3.2. Continuous Compare Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.3.3. PWM Output Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.3.4. Capture Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.4. Multi-Channel Timer Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.4.1. Timer Interrupt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.4.2. Capture/Compare Channel Interrupt . . . . . . . . . . . . . . . . . . . . . . . . 10.5. Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.5.1. Operation in HALT Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.5.2. Operation in STOP Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.5.3. Power Reduction During Operation . . . . . . . . . . . . . . . . . . . . . . . . 10.6. Multi-Channel Timer Applications Examples . . . . . . . . . . . . . . . . . . . . . . . 10.6.1. PWM Programmable Deadband Generation . . . . . . . . . . . . . . . . . 10.6.2. Multiple Timer Intervals Generation . . . . . . . . . . . . . . . . . . . . . . . PS025016-1013 PRELIMINARY 120 120 121 121 121 122 122 122 122 123 124 124 124 125 125 125 125 125 126 126 126 126 126 126 127 Table of Contents Z8 Encore! XP® F1680 Series Product Specification ix PS025016-1013 10.7. Multi-Channel Timer Control Register Definitions . . . . . . . . . . . . . . . . . . . 10.7.1. Multi-Channel Timer Address Map . . . . . . . . . . . . . . . . . . . . . . . . 10.7.2. Multi-Channel Timer High and Low Byte Registers . . . . . . . . . . . 10.7.3. Multi-Channel Timer Reload High and Low Byte Registers . . . . . 10.7.4. Multi-Channel Timer Subaddress Register . . . . . . . . . . . . . . . . . . . 10.7.5. Multi-Channel Timer Subregister x (0, 1, or 2) . . . . . . . . . . . . . . . 10.7.6. Multi-Channel Timer Control 0, Control 1 Registers . . . . . . . . . . . 10.7.7. Multi-Channel Timer Channel Status 0 and Status 1 Registers . . . 10.7.8. Multi-Channel Timer Channel-y Control Registers . . . . . . . . . . . . 10.7.9. Multi-Channel Timer Channel-y High and Low Byte Registers . . 128 128 130 130 131 132 132 135 137 139 Chapter 11. Watchdog Timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.1. Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.1.1. Watchdog Timer Refresh . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.1.2. Watchdog Timer Time-Out Response . . . . . . . . . . . . . . . . . . . . . . 11.1.3. Watchdog Timer Reload Unlock Sequence . . . . . . . . . . . . . . . . . . 11.2. Watchdog Timer Register Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.2.1. Watchdog Timer Reload High and Low Byte Registers . . . . . . . . 140 140 141 141 142 142 143 Chapter 12. LIN-UART . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.1. LIN-UART Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.1.1. Data Format for Standard UART Modes . . . . . . . . . . . . . . . . . . . . 12.1.2. Transmitting Data using the Polled Method . . . . . . . . . . . . . . . . . . 12.1.3. Transmitting Data Using Interrupt-Driven Method . . . . . . . . . . . . 12.1.4. Receiving Data Using Polled Method . . . . . . . . . . . . . . . . . . . . . . 12.1.5. Receiving Data Using the Interrupt-Driven Method . . . . . . . . . . . 12.1.6. Clear To Send Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.1.7. External Driver Enable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.1.8. LIN-UART Special Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.1.9. MULTIPROCESSOR Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.1.10.LIN Protocol Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.1.11.LIN-UART Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.1.12.LIN-UART Baud Rate Generator . . . . . . . . . . . . . . . . . . . . . . . . . . 12.2. Noise Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.2.1. Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.2.2. Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.3. LIN-UART Control Register Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . 12.3.1. LIN-UART Transmit Data Register . . . . . . . . . . . . . . . . . . . . . . . . 12.3.2. LIN-UART Receive Data Register . . . . . . . . . . . . . . . . . . . . . . . . . 12.3.3. LIN-UART Status 0 Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.3.4. LIN-UART Mode Select and Status Register . . . . . . . . . . . . . . . . . 144 144 145 146 147 148 149 150 150 151 151 153 157 160 160 161 161 163 163 164 165 168 PRELIMINARY Table of Contents Z8 Encore! XP® F1680 Series Product Specification x 12.3.5. LIN-UART Control 0 Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.3.6. LIN-UART Control 1 Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.3.7. Noise Filter Control Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.3.8. LIN Control Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12.3.9. LIN-UART Address Compare Register . . . . . . . . . . . . . . . . . . . . . 12.3.10.LIN-UART Baud Rate High and Low Byte Registers . . . . . . . . . . 170 171 174 175 177 177 Chapter 13. Infrared Encoder/Decoder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13.1. Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13.2. Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13.2.1. Transmitting IrDA Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13.2.2. Receiving IrDA Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13.3. Infrared Encoder/Decoder Control Register Definitions . . . . . . . . . . . . . . . 182 182 182 183 184 185 Chapter 14. Analog-to-Digital Converter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14.1. Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14.2. Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14.2.1. ADC Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14.2.2. ADC Interrupt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14.2.3. Reference Buffer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14.2.4. Internal Voltage Reference Generator . . . . . . . . . . . . . . . . . . . . . . 14.2.5. Calibration and Compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14.3. ADC Control Register Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14.3.1. ADC Control Register 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14.3.2. ADC Raw Data High Byte Register . . . . . . . . . . . . . . . . . . . . . . . . 14.3.3. ADC Data High Byte Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14.3.4. ADC Data Low Bits Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14.3.5. Sample Settling Time Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14.3.6. Sample Time Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14.3.7. ADC Clock Prescale Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186 186 186 187 188 188 189 189 189 189 191 191 192 193 194 195 Chapter 15. Low-Power Operational Amplifier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196 Chapter 16. Enhanced Serial Peripheral Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16.1. Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16.2. ESPI Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16.2.1. Master-In/Slave-Out . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16.2.2. Master-Out/Slave-In . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16.2.3. Serial Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16.2.4. Slave Select . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16.3. Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16.3.1. Throughput . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . PS025016-1013 PRELIMINARY 197 197 199 199 199 199 200 200 201 Table of Contents Z8 Encore! XP® F1680 Series Product Specification xi 16.3.2. ESPI Clock Phase and Polarity Control . . . . . . . . . . . . . . . . . . . . . 16.3.3. Slave Select Modes of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . 16.3.4. SPI Protocol Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16.3.5. Error Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16.3.6. ESPI Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16.3.7. ESPI Baud Rate Generator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16.4. ESPI Control Register Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16.4.1. ESPI Data Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16.4.2. ESPI Transmit Data Command and Receive Data Buffer Control Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16.4.3. ESPI Control Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16.4.4. ESPI Mode Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16.4.5. ESPI Status Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16.4.6. ESPI State Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16.4.7. ESPI Baud Rate High and Low Byte Registers . . . . . . . . . . . . . . . 201 203 207 210 211 212 213 213 Chapter 17. I2C Master/Slave Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17.1. Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17.1.1. I2C Master/Slave Controller Registers . . . . . . . . . . . . . . . . . . . . . . 17.2. Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17.2.1. SDA and SCL Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17.2.2. I2C Interrupts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17.2.3. Start and Stop Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17.2.4. Software Control of I2C Transactions . . . . . . . . . . . . . . . . . . . . . . 17.2.5. Master Transactions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17.2.6. Slave Transactions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17.3. I2C Control Register Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17.3.1. I2C Data Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17.3.2. I2C Interrupt Status Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17.3.3. I2C Control Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17.3.4. I2C Baud Rate High and Low Byte Registers . . . . . . . . . . . . . . . . 17.3.5. I2C State Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17.3.6. I2C Mode Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17.3.7. I2C Slave Address Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223 223 224 225 225 226 228 228 228 236 243 243 245 247 248 250 253 255 Chapter 18. Comparator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18.1. Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18.2. Comparator Control Register Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . 18.2.1. Comparator 0 Control Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18.2.2. Comparator 1 Control Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . 256 256 257 257 258 214 215 217 219 220 221 Chapter 19. Temperature Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260 PS025016-1013 PRELIMINARY Table of Contents Z8 Encore! XP® F1680 Series Product Specification xii 19.1. Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260 19.1.1. Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261 Chapter 20. Flash Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20.1. Flash Information Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20.2. Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20.2.1. Flash Operation Timing Using Flash Frequency Registers . . . . . . 20.2.2. Flash Code Protection Against External Access . . . . . . . . . . . . . . . 20.2.3. Flash Code Protection Against Accidental Program and Erasure . 20.2.4. Byte Programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20.2.5. Page Erase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20.2.6. Mass Erase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20.2.7. Flash Controller Bypass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20.2.8. Flash Controller Behavior in Debug Mode . . . . . . . . . . . . . . . . . . . 20.3. Flash Control Register Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20.3.1. Flash Control Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20.3.2. Flash Status Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20.3.3. Flash Page Select Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20.3.4. Flash Sector Protect Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20.3.5. Flash Frequency High and Low Byte Registers . . . . . . . . . . . . . . . 262 262 265 267 267 267 269 270 270 270 271 271 271 272 273 274 274 Chapter 21. Flash Option Bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21.1. Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21.1.1. Option Bit Configuration by Reset . . . . . . . . . . . . . . . . . . . . . . . . . 21.1.2. Option Bit Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21.2. Flash Option Bit Control Register Definitions . . . . . . . . . . . . . . . . . . . . . . 21.2.1. User Option Bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21.2.2. Trim Bit Data Option Bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21.2.3. Trim Bit Address Option Bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21.2.4. Trim Bit Address Space . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21.2.5. Zilog Calibration Option Bits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276 276 276 277 278 278 281 281 282 289 Chapter 22. Nonvolatile Data Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22.1. Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22.2. NVDS Code Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22.2.1. Byte Write . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22.2.2. Byte Read . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22.2.3. Power Failure Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22.2.4. Optimizing NVDS Memory Usage for Execution Speed . . . . . . . . 290 290 290 291 291 292 293 Chapter 23. On-Chip Debugger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 294 23.1. Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 294 PS025016-1013 PRELIMINARY Table of Contents Z8 Encore! XP® F1680 Series Product Specification xiii 23.2. Operation of the On-Chip Debugger Interface . . . . . . . . . . . . . . . . . . . . . . 23.2.1. DEBUG Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23.2.2. OCD Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23.2.3. OCD Autobaud Detector/Generator . . . . . . . . . . . . . . . . . . . . . . . . 23.2.4. High Speed Synchronous . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23.2.5. OCD Serial Errors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23.2.6. Automatic Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23.2.7. Transmit Flow Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23.2.8. Breakpoints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23.2.9. OCDCNTR Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23.3. On-Chip Debugger Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23.4. On-Chip Debugger Control Register Definitions . . . . . . . . . . . . . . . . . . . . 23.4.1. OCD Control Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23.4.2. OCD Status Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23.4.3. Line Control Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23.4.4. Baud Reload Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 295 297 298 298 299 300 301 301 301 302 303 309 310 312 313 314 Chapter 24. Oscillator Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24.1. Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24.1.1. System Clock Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24.1.2. Clock Failure Detection and Recovery . . . . . . . . . . . . . . . . . . . . . . 24.2. Peripheral Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24.3. Oscillator Control Register Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24.3.1. Oscillator Control 0 Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24.3.2. Oscillator Control1 Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315 315 315 317 318 318 318 320 Chapter 25. Crystal Oscillator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25.1. Operating Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25.2. Main Crystal Oscillator Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25.3. Main Oscillator Operation with External RC Network . . . . . . . . . . . . . . . . 25.4. Secondary Crystal Oscillator Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . 321 321 322 323 325 Chapter 26. Internal Precision Oscillator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 327 26.1. Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 327 Chapter 27. eZ8 CPU Instruction Set . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27.1. Assembly Language Programming Introduction . . . . . . . . . . . . . . . . . . . . . 27.2. Assembly Language Syntax . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27.3. eZ8 CPU Instruction Notation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27.4. eZ8 CPU Instruction Classes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27.5. eZ8 CPU Instruction Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . PS025016-1013 PRELIMINARY 328 328 329 330 331 336 Table of Contents Z8 Encore! XP® F1680 Series Product Specification xiv Chapter 28. Op Code Maps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 345 Chapter 29. Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29.1. Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29.2. DC Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29.3. AC Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29.4. On-Chip Peripheral AC and DC Electrical Characteristics . . . . . . . . . . . . . 29.4.1. General Purpose I/O Port Input Data Sample Timing . . . . . . . . . . 29.4.2. General Purpose I/O Port Output Timing . . . . . . . . . . . . . . . . . . . . 29.4.3. On-Chip Debugger Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29.4.4. UART Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 349 349 350 357 358 366 367 368 369 Chapter 30. Packaging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 371 Chapter 31. Ordering Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 372 31.1. Part Number Suffix Designations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 375 Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 377 Customer Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 387 PS025016-1013 PRELIMINARY Table of Contents Z8 Encore! XP® F1680 Series Product Specification xv List of Figures Figure 1. F1680 Series MCU Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Figure 2. Z8F2480, Z8F1680 and Z8F0880 in 20-Pin SOIC, SSOP or PDIP  Packages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Figure 3. Z8F2480, Z8F1680 and Z8F0880 in 28-Pin SOIC, SSOP or PDIP  Packages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Figure 4. Z8F2480, Z8F1680 and Z8F0880 in 40-Pin Dual Inline Package (PDIP) . 12 Figure 5. Z8F2480, Z8F1680 and Z8F0880 in 44-Pin Low-Profile Quad Flat  Package (LQFP) or Quad Flat No Lead (QFN) . . . . . . . . . . . . . . . . . . . . . . 13 Figure 6. Power-On Reset Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Figure 7. Power-On Reset Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 Figure 8. Voltage Brown-Out Reset Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 Figure 9. GPIO Port Pin Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 Figure 10. Interrupt Controller Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 Figure 11. Timer Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 Figure 12. Noise Filter System Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107 Figure 13. Noise Filter Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108 Figure 14. Multi-Channel Timer Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121 Figure 15. Count Modulo Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123 Figure 16. Count Up/Down Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123 Figure 17. Count Up/Down Mode with PWM Channel Outputs and Deadband . . . . 127 Figure 18. Count Max Mode with Channel Compare . . . . . . . . . . . . . . . . . . . . . . . . . 128 Figure 19. LIN-UART Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145 Figure 20. LIN-UART Asynchronous Data Format without Parity . . . . . . . . . . . . . . 146 Figure 21. LIN-UART Asynchronous Data Format with Parity . . . . . . . . . . . . . . . . . 146 Figure 22. LIN-UART Driver Enable Signal Timing with One Stop Bit and Parity . 151 Figure 23. LIN-UART Asynchronous MULTIPROCESSOR Mode Data Format . . 152 Figure 24. LIN-UART Receiver Interrupt Service Routine Flow . . . . . . . . . . . . . . . 159 Figure 25. Noise Filter System Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161 Figure 26. Noise Filter Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162 PS025016-1013 PRELIMINARY List of Figures Z8 Encore! XP® F1680 Series Product Specification xvi Figure 27. Infrared Data Communication System Block Diagram . . . . . . . . . . . . . . 182 Figure 28. Infrared Data Transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183 Figure 29. IrDA Data Reception . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184 Figure 30. Analog-to-Digital Converter Block Diagram . . . . . . . . . . . . . . . . . . . . . . 187 Figure 31. ADC Timing Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188 Figure 32. ADC Convert Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188 Figure 33. ESPI Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198 Figure 34. ESPI Timing when PHASE = 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202 Figure 35. ESPI Timing when PHASE = 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 203 Figure 36. SPI Mode (SSMD = 00) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205 Figure 37. Synchronous Frame Sync Pulse mode (SSMD = 10) . . . . . . . . . . . . . . . . 206 Figure 38. Synchronous Message Framing Mode (SSMD = 11), Multiple Frames . . 207 Figure 39. ESPI Configured as an SPI Master in a Single Master, Single Slave  System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208 Figure 40. ESPI Configured as an SPI Master in a Single Master, Multiple Slave  System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208 Figure 41. ESPI Configured as an SPI Slave . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210 Figure 42. I2C Controller Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224 Figure 43. Data Transfer Format—Master Write Transaction with a 7-Bit Address . 230 Figure 44. Data Transfer Format—Master Write Transaction with a 10-Bit Address 231 Figure 45. Data Transfer Format—Master Read Transaction with a 7-Bit Address . 233 Figure 46. Data Transfer Format—Master Read Transaction with a 10-Bit Address 234 Figure 47. Data Transfer Format—Slave Receive Transaction with 7-Bit Address . . 238 Figure 48. Data Transfer Format—Slave Receive Transaction with 10-Bit Address . 239 Figure 49. Data Transfer Format—Slave Transmit Transaction with 7-bit Address . 240 Figure 50. Data Transfer Format—Slave Transmit Transaction with 10-Bit Address 242 Figure 51. 8 KB Flash Memory Arrangement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263 Figure 52. 16 KB Flash Memory Arrangement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264 Figure 53. 24 KB Flash Memory Arrangement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 265 Figure 54. Flowchart: Flash Controller Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . 266 Figure 55. On-Chip Debugger Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 294 PS025016-1013 PRELIMINARY List of Figures Z8 Encore! XP® F1680 Series Product Specification xvii Figure 56. Target OCD Connector Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 296 Figure 57. Interfacing the On-Chip Debugger’s DBG Pin with an RS-232 Interface,  #1 of 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 296 Figure 58. Interfacing the On-Chip Debugger’s DBG Pin with an RS-232 Interface,  #2 of 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 297 Figure 59. OCD Data Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 298 Figure 60. Synchronous Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300 Figure 61. Start Bit Flow Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 301 Figure 62. Recommended 20 MHz Crystal Oscillator Configuration . . . . . . . . . . . . . 322 Figure 63. Connecting the On-Chip Oscillator to an External RC Network . . . . . . . . 323 Figure 64. Typical RC Oscillator Frequency as a Function of External Capacitance 324 Figure 65. Recommended 32 kHz Crystal Oscillator Configuration . . . . . . . . . . . . . . 325 Figure 66. Op Code Map Cell Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 345 Figure 67. First Op Code Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 347 Figure 68. Second Op Code Map after 1Fh . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 348 Figure 69. Typical Active Flash Mode Supply Current (1–20 MHz) . . . . . . . . . . . . . 353 Figure 70. Typical Active PRAM Mode Supply Current (1–20 MHz) . . . . . . . . . . . . 354 Figure 71. Typical Active Flash Mode Supply Current (32–900 kHz) . . . . . . . . . . . . 354 Figure 72. Typical Active PRAM Mode Supply Current (32–900 kHz) . . . . . . . . . . . 355 Figure 73. STOP Mode Current Consumption as a Function of VDD with  Temperature as a Parameter; all Peripherals Disabled . . . . . . . . . . . . . . . 356 Figure 74. VDD Versus Maximum System Clock Frequency . . . . . . . . . . . . . . . . . . 357 Figure 75. Port Input Sample Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 366 Figure 76. GPIO Port Output Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 367 Figure 77. On-Chip Debugger Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 368 Figure 78. UART Timing With CTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 369 Figure 79. UART Timing Without CTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 370 PS025016-1013 PRELIMINARY List of Figures Z8 Encore! XP® F1680 Series Product Specification xviii List of Tables PS025016-1013 Table 1. Z8 Encore! XP F1680 Series Part Selection Guide . . . . . . . . . . . . . . . . . . . . 2 Table 2. F1680 Series MCU Acronyms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Table 3. Z8 Encore! XP F1680 Series Package Options . . . . . . . . . . . . . . . . . . . . . . 10 Table 4. Signal Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Table 5. Pin Characteristics (20-, 28-, 40- and 44-pin Devices). . . . . . . . . . . . . . . . . 17 Table 6. F1680 Series MCU Program Memory Maps . . . . . . . . . . . . . . . . . . . . . . . . 20 Table 7. F1680 Series MCU Flash Memory Information Area Map . . . . . . . . . . . . . 22 Table 8. Register File Address Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Table 9. Reset and Stop Mode Recovery Characteristics and Latency . . . . . . . . . . . 32 Table 10. Reset Sources and Resulting Reset Type . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Table 11. Stop Mode Recovery Sources and Resulting Action . . . . . . . . . . . . . . . . . . 38 Table 12. Reset Status Register (RSTSTAT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Table 13. Reset Status Per Event . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 Table 14. Power Control Register 0 (PWRCTL0) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 Table 15. Setup Condition for LVD and VBO Circuits in Different Operation Modes 45 Table 16. Port Availability by Device and Package Type . . . . . . . . . . . . . . . . . . . . . . 46 Table 17. Port Alternate Function Mapping, 20-Pin Parts1,2. . . . . . . . . . . . . . . . . . . . 49 Table 18. Port Alternate Function Mapping, 28-Pin Parts1,2. . . . . . . . . . . . . . . . . . . . 51 Table 19. Port Alternate Function Mapping, 40-/44-Pin Parts1,2 . . . . . . . . . . . . . . . . 54 Table 20. GPIO Port Registers and Subregisters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 Table 21. Port A–E GPIO Address Registers (PxADDR) . . . . . . . . . . . . . . . . . . . . . . 59 Table 22. Port A–E Control Registers (PxCTL). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 Table 23. Port A–E Data Direction Subregisters (PxDD) . . . . . . . . . . . . . . . . . . . . . . 60 Table 24. Port A–E Alternate Function Subregisters (PxAF). . . . . . . . . . . . . . . . . . . . 61 Table 25. Port A–E Output Control Subregisters (PxOC) . . . . . . . . . . . . . . . . . . . . . . 62 Table 26. Port A–E High Drive Enable Subregisters (PxHDE) . . . . . . . . . . . . . . . . . . 62 Table 27. Port A–E Stop Mode Recovery Source Enable Subregisters (PxSMRE). . . 63 Table 28. Port A–E Pull-Up Enable Subregisters (PxPUE) . . . . . . . . . . . . . . . . . . . . . 63 PRELIMINARY List of Tables Z8 Encore! XP® F1680 Series Product Specification xix PS025016-1013 Table 29. Port A–E Alternate Function Set 1 Subregisters (PxAFS1) . . . . . . . . . . . . . 64 Table 30. Port A–E Alternate Function Set 2 Subregisters (PxAFS2) . . . . . . . . . . . . . 65 Table 31. Port A–E Input Data Registers (PxIN) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 Table 32. Port A–E Output Data Register (PxOUT) . . . . . . . . . . . . . . . . . . . . . . . . . . 66 Table 33. LED Drive Enable (LEDEN) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66 Table 34. LED Drive Level High Bit Register (LEDLVLH) . . . . . . . . . . . . . . . . . . . . 67 Table 35. LED Drive Level Low Bit Register (LEDLVLL) . . . . . . . . . . . . . . . . . . . . 67 Table 36. Trap and Interrupt Vectors in Order of Priority . . . . . . . . . . . . . . . . . . . . . . 69 Table 37. Interrupt Request 0 Register (IRQ0). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 Table 38. Interrupt Request 1 Register (IRQ1). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 Table 39. Interrupt Request 2 Register (IRQ2). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 Table 40. IRQ0 Enable and Priority Encoding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76 Table 41. IRQ0 Enable High Bit Register (IRQ0ENH) . . . . . . . . . . . . . . . . . . . . . . . . 76 Table 42. IRQ0 Enable Low Bit Register (IRQ0ENL). . . . . . . . . . . . . . . . . . . . . . . . . 77 Table 43. IRQ1 Enable and Priority Encoding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 Table 44. IRQ1 Enable High Bit Register (IRQ1ENH) . . . . . . . . . . . . . . . . . . . . . . . . 78 Table 45. IRQ2 Enable and Priority Encoding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79 Table 46. IRQ1 Enable Low Bit Register (IRQ1ENL). . . . . . . . . . . . . . . . . . . . . . . . . 79 Table 47. IRQ2 Enable High Bit Register (IRQ2ENH) . . . . . . . . . . . . . . . . . . . . . . . . 80 Table 48. IRQ2 Enable Low Bit Register (IRQ2ENL). . . . . . . . . . . . . . . . . . . . . . . . . 81 Table 49. Interrupt Edge Select Register (IRQES). . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 Table 50. Shared Interrupt Select Register (IRQSS) . . . . . . . . . . . . . . . . . . . . . . . . . . 82 Table 51. Interrupt Control Register (IRQCTL). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 Table 52. Timer Operating Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 Table 53. TRIGGERED ONE-SHOT Mode Initialization Example . . . . . . . . . . . . . . 89 Table 54. DEMODULATION Mode Initialization Example . . . . . . . . . . . . . . . . . . . 105 Table 55. Timer 0–2 High Byte Register (TxH). . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109 Table 56. Timer 0–2 Low Byte Register (TxL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109 Table 57. Timer 0–2 Reload High Byte Register (TxRH) . . . . . . . . . . . . . . . . . . . . . 110 Table 58. Timer 0–2 Reload Low Byte Register (TxRL). . . . . . . . . . . . . . . . . . . . . . 110 PRELIMINARY List of Tables Z8 Encore! XP® F1680 Series Product Specification xx PS025016-1013 Table 59. Timer 0–2 PWM0 High Byte Register (TxPWM0h) . . . . . . . . . . . . . . . . . 110 Table 60. Timer 0-2 PWM1 High Byte Register (TxPWM1h) . . . . . . . . . . . . . . . . . 111 Table 61. Timer 0–2 PWM1 Low Byte Register (TxPWM1L) . . . . . . . . . . . . . . . . . 111 Table 62. Timer 0–2 PWM0 Low Byte Register (TxPWM0L) . . . . . . . . . . . . . . . . . 111 Table 63. Timer 0–2 Control 0 Register (TxCTL0) . . . . . . . . . . . . . . . . . . . . . . . . . . 112 Table 64. Timer 0–2 Control 1 Register (TxCTL1) . . . . . . . . . . . . . . . . . . . . . . . . . . 113 Table 65. Timer 0–2 Control 2 Register (TxCTL2) . . . . . . . . . . . . . . . . . . . . . . . . . . 117 Table 66. Timer 0–2 Status Register (TxSTAT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118 Table 67. Timer 0–2 Noise Filter Control Register (TxNFC) . . . . . . . . . . . . . . . . . . 119 Table 68. Timer Count Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122 Table 69. Multi-Channel Timer Address Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129 Table 70. Multi-Channel Timer High and Low Byte Registers (MCTH, MCTL) . . . 130 Table 71. Multi-Channel Timer Reload High and Low Byte Registers  (MCTRH, MCTRL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131 Table 72. Multi-Channel Timer Subaddress Register (MCTSA) . . . . . . . . . . . . . . . . 132 Table 73. Multi-Channel Timer Subregister x (MCTSRx). . . . . . . . . . . . . . . . . . . . . 132 Table 74. Multi-Channel Timer Control 0 Register (MCTCTL0) . . . . . . . . . . . . . . . 132 Table 75. Multi-Channel Timer Control 1 Register (MCTCTL1) . . . . . . . . . . . . . . . 134 Table 76. Multi-Channel Timer Channel Status 0 Register (MCTCHS0) . . . . . . . . . 135 Table 77. Multi-Channel Timer Channel Status 1 Register (MCTCHS1) . . . . . . . . . 136 Table 78. Multi-Channel Timer Channel Control Register (MCTCHyCTL). . . . . . . 137 Table 79. Multi-Channel Timer Channel-y High Byte Registers (MCTCHyH)* . . . 139 Table 80. Watchdog Timer Approximate Time-Out Delays . . . . . . . . . . . . . . . . . . . 141 Table 81. Watchdog Timer Reload High Byte Register (WDTH = FF2h). . . . . . . . . 143 Table 82. Watchdog Timer Reload Low Byte Register . . . . . . . . . . . . . . . . . . . . . . . 143 Table 83. LIN-UART Transmit Data Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163 Table 84. LIN-UART Receive Data Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164 Table 85. LIN-UART Status 0 Register—Standard UART Mode  (U0STAT0 = F41h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165 Table 86. LIN-UART Status 0 Register—LIN Mode (U0STAT0 = F41h) . . . . . . . . 166 Table 87. LIN-UART Mode Select and Status Register (U0MDSTAT = F44h) . . . . 168 PRELIMINARY List of Tables Z8 Encore! XP® F1680 Series Product Specification xxi Table 88. Mode Status Fields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169 Table 89. LIN-UART Control 0 Register (U0CTL0 = F42h) . . . . . . . . . . . . . . . . . . 170 Table 90. Multiprocessor Control Register (U0CTL1 = F43h with MSEL = 000b) . 172 Table 91. Noise Filter Control Register (U0CTL1 = F43h with MSEL = 001b) . . . . 174 Table 92. LIN Control Register (U0CTL1 = F43h with MSEL = 010b) . . . . . . . . . . 175 Table 93. LIN-UART Address Compare Register (U0ADDR = F45h) . . . . . . . . . . . 177 Table 94. LIN-UART Baud Rate High Byte Register (U0BRH = F46h). . . . . . . . . . 177 Table 95. LIN-UART Baud Rate Low Byte Register (U0BRL = F47h) . . . . . . . . . . 178 Table 96. LIN-UART Baud Rates, 20.0 MHz System Clock . . . . . . . . . . . . . . . . . . . 179 Table 97. LIN-UART Baud Rates, 10.0 MHz System Clock . . . . . . . . . . . . . . . . . . . 179 Table 98. LIN-UART Baud Rates, 5.5296 MHz System Clock . . . . . . . . . . . . . . . . . 180 Table 99. LIN-UART Baud Rates, 3.579545 MHz System Clock . . . . . . . . . . . . . . . 180 Table 100. LIN-UART Baud Rates, 1.8432 MHz System Clock . . . . . . . . . . . . . . . . 181 Table 101. ADC Control Register 0 (ADCCTL0) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189 Table 102. ADC Raw Data High Byte Register (ADCRD_H). . . . . . . . . . . . . . . . . . . 191 Table 103. ADC Data High Byte Register (ADCD_H) . . . . . . . . . . . . . . . . . . . . . . . . 191 Table 104. ADC Data Low Bits Register (ADCD_L) . . . . . . . . . . . . . . . . . . . . . . . . . 192 Table 105. Sample Settling Time (ADCSST). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193 Table 106. Sample Time (ADCST) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194 Table 107. ADC Clock Prescale Register (ADCCP) . . . . . . . . . . . . . . . . . . . . . . . . . . 195 Table 108. ESPI Clock Phase (PHASE) and Clock Polarity (CLKPOL) Operation . . 201 Table 109. ESPI Data Register (ESPIDATA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214 Table 110. ESPI Transmit Data Command and Receive Data Buffer Control Register (ESPITDCR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214 Table 111. ESPI Control Register. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215 Table 112. ESPI Mode Register (ESPIMODE) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217 Table 113. ESPI Status Register (ESPISTAT) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219 Table 114. ESPI State Register (ESPISTATE). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220 Table 115. ESPISTATE Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221 Table 116. ESPI Baud Rate High Byte Register (ESPIBRH) . . . . . . . . . . . . . . . . . . . 222 Table 117. ESPI Baud Rate Low Byte Register (ESPIBRL) . . . . . . . . . . . . . . . . . . . . 222 PS025016-1013 PRELIMINARY List of Tables Z8 Encore! XP® F1680 Series Product Specification xxii Table 118. I2C Master/Slave Controller Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . 224 Table 119. I2C Data Register (I2CDATA = F50h) . . . . . . . . . . . . . . . . . . . . . . . . . . . 244 Table 120. I2C Interrupt Status Register (I2CISTAT = F51h). . . . . . . . . . . . . . . . . . . 245 Table 121. I2C Control Register (I2CCTL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247 Table 122. I2C Baud Rate High Byte Register (I2CBRH = 53h). . . . . . . . . . . . . . . . . 248 Table 123. I2C Baud Rate Low Byte Register (I2CBRL = F54h) . . . . . . . . . . . . . . . . 249 Table 124. I2C State Register (I2CSTATE)—Description when DIAG = 1 . . . . . . . . 250 Table 125. I2C State Register (I2CSTATE)—Description when DIAG = 0 . . . . . . . . 251 Table 126. I2CSTATE_L . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 252 Table 127. I2CSTATE_H . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 252 Table 128. I2C Mode Register (I2C Mode = F56h) . . . . . . . . . . . . . . . . . . . . . . . . . . . 253 Table 129. I2C Slave Address Register (I2CSLVAD = 57h). . . . . . . . . . . . . . . . . . . . 255 Table 130. Comparator 0 Control Register (CMP0). . . . . . . . . . . . . . . . . . . . . . . . . . . 257 Table 131. Comparator 1 Control Register (CMP1). . . . . . . . . . . . . . . . . . . . . . . . . . . 258 Table 132. Z8 Encore! XP F1680 Series Flash Memory Configurations. . . . . . . . . . . 262 Table 133. Flash Code Protection Using the Flash Option Bit. . . . . . . . . . . . . . . . . . . 268 Table 134. Flash Control Register (FCTL). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 272 Table 135. Flash Status Register (FSTAT). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 272 Table 136. Flash Page Select Register (FPS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273 Table 137. Flash Sector Protect Register (FPROT) . . . . . . . . . . . . . . . . . . . . . . . . . . . 274 Table 138. Flash Frequency High Byte Register (FFREQH) . . . . . . . . . . . . . . . . . . . . 275 Table 139. Flash Frequency Low Byte Register (FFREQL) . . . . . . . . . . . . . . . . . . . . 275 Table 140. Flash Option Bits at Program Memory Address 0000h . . . . . . . . . . . . . . . 278 Table 141. Flash Option Bits at Program Memory Address 0001h . . . . . . . . . . . . . . . 280 Table 142. Trim Bit Data Register (TRMDR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 281 Table 143. Trim Bit Address Register (TRMADR) . . . . . . . . . . . . . . . . . . . . . . . . . . . 281 Table 144. Trim Bit Address Map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 281 Table 145. Trim Bit Address Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 282 Table 146. Trim Option Bits at Address 0000h (TTEMP0) . . . . . . . . . . . . . . . . . . . . . 282 Table 147. Trim Option Bits at 0001h (TTEMP1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 283 PS025016-1013 PRELIMINARY List of Tables Z8 Encore! XP® F1680 Series Product Specification xxiii Table 148. Trim Option Bits at 0002h (TIPO) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 283 Table 149. Trim Option Bits at Address 0003h (TLVD_VBO) . . . . . . . . . . . . . . . . . . 284 Table 150. LVD_Trim Values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 284 Table 151. Trim Option Bits at 0004h (TCOMP_ADC) . . . . . . . . . . . . . . . . . . . . . . . 286 Table 152. Truth Table of HYS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 286 Table 153. Trim Option Bits at 0005h (TVREF) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 287 Table 154. Trim Option Bits at 0006h (TBG) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 287 Table 155. Trim Option Bits at 0007h (TFilter0) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 288 Table 156. Trim Option Bits at 0008h (TFilter1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 288 Table 157. Temperature Sensor Calibration High Byte at FE60h (TEMPCALH). . . . 289 Table 158. Temperature Sensor Calibration Low Byte at FE61h (TEMPCALL) . . . . 289 Table 159. Write Status Byte . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 291 Table 160. Read Status Byte. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 292 Table 161. NVDS Read Time. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293 Table 162. OCD Baud-Rate Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299 Table 163. On-Chip Debugger Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 304 Table 164. OCD Control Register (OCDCTL). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 310 Table 165. OCD Status Register (OCDSTAT). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 312 Table 166. OCD Line Control Register (OCDLCR) . . . . . . . . . . . . . . . . . . . . . . . . . . 313 Table 167. Baud Reload Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 314 Table 168. Oscillator Configuration and Selection. . . . . . . . . . . . . . . . . . . . . . . . . . . . 316 Table 169. Peripheral Clock Source and Usage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 318 Table 170. Oscillator Control 0 Register (OSCCTL0) . . . . . . . . . . . . . . . . . . . . . . . . . 319 Table 171. Oscillator Control 1 Register (OSCCTL1) . . . . . . . . . . . . . . . . . . . . . . . . . 320 Table 172. Recommended Crystal Oscillator Specifications . . . . . . . . . . . . . . . . . . . . 323 Table 173. Recommended Crystal Oscillator Specifications . . . . . . . . . . . . . . . . . . . . 326 Table 174. Assembly Language Syntax Example 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . 329 Table 175. Assembly Language Syntax Example 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . 329 Table 176. Notational Shorthand . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 330 Table 177. Additional Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 331 PS025016-1013 PRELIMINARY List of Tables Z8 Encore! XP® F1680 Series Product Specification xxiv Table 178. Arithmetic Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 332 Table 179. Bit Manipulation Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 333 Table 180. Block Transfer Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 333 Table 181. CPU Control Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 333 Table 182. Logical Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 334 Table 183. Load Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 334 Table 184. Program Control Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 335 Table 185. Rotate and Shift Instructions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 335 Table 186. eZ8 CPU Instruction Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 336 Table 187. Op Code Map Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 346 Table 188. Absolute Maximum Ratings* . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 349 Table 189. DC Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 350 Table 190. Supply Current Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 352 Table 191. AC Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 357 Table 192. Power-On Reset and Voltage Brown-Out Electrical Characteristics  and Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 358 Table 193. Flash Memory Electrical Characteristics and Timing . . . . . . . . . . . . . . . . 359 Table 194. Watchdog Timer Electrical Characteristics and Timing. . . . . . . . . . . . . . . 359 Table 195. Non-Volatile Data Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 359 Table 196. Analog-to-Digital Converter Electrical Characteristics and Timing . . . . . 360 Table 197. Comparator Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . 361 Table 198. Temperature Sensor Electrical Characteristics . . . . . . . . . . . . . . . . . . . . . . 361 Table 199. Low Power Operational Amplifier Characteristics . . . . . . . . . . . . . . . . . . 362 Table 200. IPO Electrical Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 362 Table 201. Low Voltage Detect Electrical Characteristics. . . . . . . . . . . . . . . . . . . . . . 363 Table 202. Crystal Oscillator Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 364 Table 203. Low Power 32 kHz Secondary Oscillator Characteristics . . . . . . . . . . . . . 365 Table 204. GPIO Port Input Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 366 Table 205. GPIO Port Output Timing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 367 Table 206. On-Chip Debugger Timing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 368 Table 207. UART Timing with CTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 369 PS025016-1013 PRELIMINARY List of Tables Z8 Encore! XP® F1680 Series Product Specification xxv Table 208. UART Timing Without CTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 370 Table 209. Ordering Information for the Z8 Encore! XP F1680 Series of MCUs . . . . 372 Table 210. Package and Pin Count Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 376 PS025016-1013 PRELIMINARY List of Tables Z8 Encore! XP® F1680 Series Product Specification 1 Chapter 1. Overview Zilog’s F1680 Series of MCUs is based on Zilog’s advanced 8-bit eZ8 CPU core. This microcontroller, a member of the Z8 Encore! XP® product line, is optimized for lowpower applications and supports 1.8 V to 3.6 V of low-voltage operation with extremely low Active, Halt and Stop Mode currents, plus it offers a wide assortment of speed and low-power options. In addition, the feature-rich analog and digital peripherals of the Z8 Encore! XP F1680 Series of MCUs makes them suitable for a variety of applications including safety and security, utility metering, digital power supervisory, hand-held electronic devices and general motor control applications. For simplicity, the remainder of this document refers to the entire Z8 Encore! XP F1680 Series of MCUs as the F1680 Series MCU. 1.1. Features Key features of the F1680 Series MCU include: PS025016-1013 • • • • • • • • • • 20 MHz eZ8 CPU core • Infrared Data Association (IrDA)-compliant infrared encoders/decoders, integrated with UARTs • • • • Enhanced Serial Peripheral Interface (SPI) controller (except 20-pin packages) 8 KB, 16 KB, or 24 KB Flash memory with in-circuit programming capability 1 KB or 2 KB Register RAM 1 KB Program RAM for program code shadowing and data storage (optional) 128 B or 256 B Non-Volatile Data Storage (NVDS) Up to 8-Channel, 10-bit Analog-to-Digital Converter (ADC) On-chip Temperature Sensor Up to two on-chip analog comparators (20-pin and 28-pin packages contain only one) On-chip Low-Power Operational Amplifier (LPO) Two full-duplex 9-bit UART ports with the support of Local Interconnect Network (LIN) protocol (20-pin and 28-pin packages contain only one) I2C controller which supports Master/Slave modes Three enhanced 16-bit Timers with Capture, Compare and PWM capability Additional two basic 16-bit timers with interrupt (shared as UART Baud Rate Generator) PRELIMINARY Overview Z8 Encore! XP® F1680 Series Product Specification 2 1.2. • Optional 16-bit Multi-Channel Timer which supports four Capture/Compare/PWM modules (44-pin packages only) • • • • • • • • • Watchdog Timer (WDT) with dedicated internal RC oscillator • • • • Crystal oscillator with three power settings and external RC network option 17 to 37 General-Purpose Input/Output (GPIO) pins depending upon package Up to 8 direct LED drives with programmable drive current capability Up to 31 interrupt sources with up to 24 interrupt vectors On-Chip Debugger (OCD) Power-On Reset (POR) and Voltage Brown-Out (VBO) protection Built-in Low-Voltage Detection (LVD) with programmable voltage threshold 32 kHz secondary oscillator for Timers Internal Precision Oscillator (IPO) with output frequency in the range of 43.2 kHz to 11.0592 MHz Wide operation voltage range: 1.8 V–3.6 V 20-, 28-, 40- and 44-pin packages 0° C to +70° C (standard) and –40° C to +105° C (extended) operating temperature ranges Part Selection Guide Table 1 displays basic features and package styles available for each of the F1680 Series MCUs. Table 1. Z8 Encore! XP F1680 Series Part Selection Guide Part Number Flash RAM Program NVDS (KB) (B) RAM (B) (B) I/O ADC Inputs SPI I2C UARTs Packages Z8F2480 24 2048 1024 — 17–37 7–8 0–1 1 1–2 20-, 28-, 40- and 44-pin Z8F1680 16 2048 1024 256 17–37 7–8 0–1 1 1–2 20-, 28-, 40- and 44-pin Z8F0880 8 1024 1024 128 17–37 7–8 0–1 1 1–2 20-, 28-, 40- and 44-pin PS025016-1013 PRELIMINARY Overview Z8 Encore! XP® F1680 Series Product Specification 3 1.3. Block Diagram Figure 1 displays the architecture of the F1680 Series MCU. WDT with RC Oscillator POR/VBO Reset Control Low-Power 32 kHz Secondary Oscillator Low-Voltage Detector Multichannel Timer Enhanced SPI Internal Precision/ Crystal Oscillator I2C Master/Slave eZ8 20 MHz CPU 8 Channel 10-Bit A/D Converter On-Chip Debugger 3 x 16-Bit Timer/PWM Temperature Sensor Program RAM 1 KB x 8 Low-power Operational Amplifier Register File 2 KB x 8 NVDS 256 B x 8 2 UARTs with LIN and IrDA Flash Program Memory 24 KB x 8 Interrupt Controller 2 Analog Comparators Port A Port B Port C Port D Port E Figure 1. F1680 Series MCU Block Diagram PS025016-1013 PRELIMINARY Overview Z8 Encore! XP® F1680 Series Product Specification 4 1.4. An Overview of the eZ8 CPU and its Peripherals Zilog’s eZ8 CPU, latest 8-bit CPU meets the continuing demand for faster and more codeefficient microcontrollers. It executes a superset of the original Z8® instruction set. The eZ8 CPU features include: • Direct register-to-register architecture allows each register to function as an accumulator, improving execution time and decreasing the required program memory • Software stack allows greater depth in subroutine calls and interrupts more than hardware stacks • • • Compatible with existing Z8 code • • Pipelined instruction fetch and execution • • • • New instructions support 12-bit linear addressing of the register file Expanded internal Register File allows access up to 4 KB New instructions improve execution efficiency for code developed using higher-level programming languages including C New instructions for improved performance including BIT, BSWAP, BTJ, CPC, LDC, LDCI, LEA, MULT and SRL Up to 10 MIPS operation C-Compiler friendly 2 to 9 clock cycles per instruction For more details about eZ8 CPU, refer to the eZ8 CPU Core User Manual (UM0128), available for download at www.zilog.com. 1.4.1. General-Purpose Input/Output The F1680 MCU features 17 to 37 port pins (Ports A–E) for general purpose input/output (GPIO) pins. The number of GPIO pins available is a function of package. Each pin is individually programmable. 1.4.2. Flash Controller The Flash Controller is used to program and erase Flash memory. The Flash Controller supports protection against accidental program and erasure. PS025016-1013 PRELIMINARY Overview Z8 Encore! XP® F1680 Series Product Specification 5 1.4.3. Non-Volatile Data Storage Non-Volatile Data Storage (NVDS) is a hybrid hardware/software scheme to implement byte-programmable data memory and is capable of over 100,000 write cycles. 1.4.4. Internal Precision Oscillator The internal precision oscillator (IPO) is a trimmable clock source which requires no external components. You can select IPO frequency from one of eight frequencies (43.2 kHz to 11.0592 MHz) and is available with factory-trimmed calibration data. 1.4.5. Crystal Oscillator The crystal oscillator circuit provides highly accurate clock frequencies using an external crystal, ceramic resonator, or RC network. 1.4.6. Secondary Oscillator The secondary oscillator is a low-power oscillator, which is optimized for use with a 32 kHz watch crystal. It can be used as timer/counter clock source in any mode. 1.4.7. 10-Bit Analog-to-Digital Converter The Analog-to-Digital Converter (ADC) converts an analog input signal to a 10-bit binary number. The ADC supports up to eight analog input sources multiplexed with GPIO ports. 1.4.8. Low-Power Operational Amplifier The low-power operational amplifier (LPO) is a general-purpose operational amplifier primarily targeted for current sense applications. The LPO output can be internally routed to the ADC or externally to a pin. 1.4.9. Analog Comparator The analog comparator compares the signal at an input pin with either an internal programmable voltage reference or a second-input pin. The comparator output is used to either drive an output pin or to generate an interrupt. PS025016-1013 PRELIMINARY Overview Z8 Encore! XP® F1680 Series Product Specification 6 1.4.10. Temperature Sensor The temperature sensor produces an analog output proportional to the device temperature. This signal is sent either to the ADC or to the analog comparator. 1.4.11. Low-Voltage Detector The low-voltage detector generates an interrupt when the supply voltage drops below a user-programmable level. 1.4.12. Enhanced SPI The enhanced SPI is a full-duplex, buffered, synchronous character-oriented channel which supports a four-wire interface. 1.4.13. UART with LIN A full-duplex 9-bit UART provides serial, asynchronous communication and supports the local interconnect network (LIN) serial communications protocol. The UART supports 8bit and 9-bit data modes, selectable parity and an efficient bus transceiver Driver Enable signal for controlling a multi-transceiver bus, such as RS-485. The LIN bus is a cost-efficient, single-master, multiple-slave organization which supports speed up to 20 KBits. 1.4.14. Master/Slave I2C The inter-integrated circuit (I2C) controller makes the F1680 Series MCU compatible with the I2C protocol. The I2C controller consists of two bidirectional bus lines: 1. Serial data (SDA) line 2. Serial clock (SCL) line It also supports Master, Slave and Multi-Master Operations 1.4.15. Timers Three enhanced 16-bit reloadable timers are used for timing/counting events or motor control operations. These timers provide a 16-bit programmable reload counter and operate in ONE-SHOT, CONTINUOUS, GATED, CAPTURE, CAPTURE RESTART, COMPARE, CAPTURE and COMPARE, PWM SINGLE OUTPUT, PWM DUAL OUTPUT, TRIGGERED ONE-SHOT and DEMODULATION modes. In addition to these three enhanced 16-bit timers, there are two basic 16-bit timers with interrupt function. The two timers are PS025016-1013 PRELIMINARY Overview Z8 Encore! XP® F1680 Series Product Specification 7 used as Baud Rate Generator (BRG) when UART is enabled and configured as basic 16bit timers when UART is disabled. 1.4.16. Multi-Channel Timer The multi-channel timer has a 16-bit up/down counter and a 4-channel Capture/Compare/ PWM channel array. This timer enables the support of multiple synchronous Capture/ Compare/PWM channels based on a single timer. 1.4.17. Interrupt Controller The Z8 Encore! XP F1680 Series products support up to thirty-one interrupt sources with twenty-four interrupt vectors. These interrupts consist of up to fifteen internal peripheral interrupts and up to sixteen GPIO pin interrupts. The interrupts have three levels of programmable-interrupt priority. 1.4.18. Reset Controller The F1680 Series MCU is reset using the RESET pin, POR, WDT time-out, STOP Mode exit, or VBO warning signal. The RESET pin is bidirectional, that is, it functions as reset source as well as a reset indicator. 1.4.19. On-Chip Debugger The F1680 Series MCU features an integrated OCD. The OCD provides a rich-set of debugging capabilities, such as reading and writing registers, programming Flash memory, setting breakpoints and executing code. The OCD uses one single-pin interface for communication with an external host. 1.4.20. Direct LED Drive The Port C pins also provide a current synchronized output capable of driving an LED without requiring any external resistor. Up to eight LEDs are driven with individually programmable drive current level from 3 mA to 20 mA. PS025016-1013 PRELIMINARY Overview Z8 Encore! XP® F1680 Series Product Specification 8 1.5. Acronyms and Expansions This document uses the acronyms and expansions listed in Table 2. Table 2. F1680 Series MCU Acronyms PS025016-1013 Abbreviations/ Acronyms Expansions ADC Analog-to-Digital Converter NVDS Non-Volatile Data Storage LPO Low-Power Operational Amplifier LIN Local Interconnect Network SPI Serial Peripheral Interface ESPI Enhanced Serial Peripheral Interface WDT Watchdog Timer GPIO General-Purpose Input/Output OCD On-Chip Debugger POR Power-On Reset LVD Low-Voltage Detection VBO Voltage Brown-Out IPO Internal Precision Oscillator UART Universal Asynchronous Receiver/Transmitter IrDA Infrared Data Association I2C Inter-integrated circuit PDIP Plastic Dual Inline Package SOIC Small Outline Integrated Circuit SSOP Small Shrink Outline Package QFN Quad Flat No Lead LQFP Low-Profile Quad Flat Package PRAM Program RAM PC Program counter IRQ Interrupt request ISR Interrupt service routine MSB Most-significant byte PRELIMINARY Overview Z8 Encore! XP® F1680 Series Product Specification 9 Table 2. F1680 Series MCU Acronyms (Continued) Abbreviations/ Acronyms Expansions LSB Least-significant byte PWM Pulse-Width Modulation CI Channel Interrupt TI Timer Interrupt Endec Encoder/Decoder 2 PS025016-1013 I S Inter IC Sound TDM Time division multiplexing TTL Transistor-Transistor Logic SAR Successive Approximation Register PRELIMINARY Overview Z8 Encore! XP® F1680 Series Product Specification 10 Chapter 2. Pin Description The F1680 Series MCU is available in a variety of package styles and pin configurations. This chapter describes the signals and available pin configurations for each of the package styles. For information about the physical package specifications, see the Packaging chapter on page 371. 2.1. Available Packages Table 3 lists the package styles available for each device in the Z8 Encore! XP F1680 Series product line. Table 3. Z8 Encore! XP F1680 Series Package Options Part Number ADC 20-pin PDIP 20-pin SOIC 20-pin SSOP 28-pin PDIP 28-pin SOIC 28-pin SSOP 40-pin PDIP 44-pin QFN 44-pin LQFP Z8F2480 Yes X X X X X X X X X Z8F1680 Yes X X X X X X X X X Z8F0880 Yes X X X X X X X X X 2.2. Pin Configurations Figures 2 through 5 display the pin configurations of all the packages available in the F1680 Series MCU. For description of the signals, see Table 4 on page 14. At reset, all port pins default to an input state. In addition, any alternate functionality is not enabled, so the pins function as general-purpose input ports until programmed otherwise. At power up, the Port D0 pin defaults to the RESET alternate function. The pin configurations listed are preliminary and subject to change based on manufacturing limitations. PS025016-1013 PRELIMINARY Pin Description Z8 Encore! XP® F1680 Series Product Specification 11 PB1/ANA1/AMPINN PB2/ANA2/AMPINP PB3/CLKIN/ANA3 VDD PA0/T0IN/T0OUT/XIN PA1/T0OUT/XOUT VSS PA2/DE0/X2IN PA3/CTS0/X2OUT PA4/RXD0/IRRX0/T2IN/T2OUT 20 19 18 17 16 15 14 13 12 11 1 2 3 4 5 6 7 8 9 10 PB0/ANA0/AMPOUT PC3/C0OUT/LED PC2/ANA6/LED/VREF PC1/ANA5/C0INN/LED PC0/ANA4/C0INP/LED DBG RESET/PD0 PA7/T1OUT/SDA PA6/T1IN/T1OUT/SCL PA5/TXD0/IRTX0/T2OUT Figure 2. Z8F2480, Z8F1680 and Z8F0880 in 20-Pin SOIC, SSOP or PDIP Packages PB2/ANA2/AMPINP PB4/ANA7 PB5/VREF PB3/CLKIN/ANA3 AVDD VDD PA0/T0IN/T0OUT/XIN PA1/T0OUT/XOUT VSS AVSS PA2/DE0/X2IN PA3/CTS0/X2OUT PA4/RXD0/IRRX0 PA5/TXD0/IRTX0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 28 27 26 25 24 23 22 21 20 19 18 17 16 15 PB1/ANA1/AMPINN PB0/ANA0/AMPOUT PC3/C0OUT/LED PC2/ANA6/LED/SS PC1/ANA5/C0INN/LED/MISO PC0/ANA4/C0INP/LED DBG RESET/PD0 PC7/LED/T2OUT PC6/LED/T2IN/T2OUT PA7/T1OUT/SDA PC5/LED/SCK PC4/LED/MOSI PA6/T1IN/T1OUT/SCL Figure 3. Z8F2480, Z8F1680 and Z8F0880 in 28-Pin SOIC, SSOP or PDIP Packages PS025016-1013 PRELIMINARY Pin Description Z8 Encore! XP® F1680 Series Product Specification 12 PB1/AMPINN/ANA1 1 40 PB4/ANA7 PB5/VREF PB3/CLKIN/ANA3 PD2/C1INP PC3/MISO/LED PC2/ANA6/SS/LED 5 35 PE0 AVDD VDD PA0/T0IN/T0OUT/XIN PA1/T0OUT/XOUT PD3/CTS1/C1OUT DBG 10 30 PD0/RESET VDD PE1/SCL PE2/SDA PC7/T2OUT/LED PC6/T2IN/T2OUT/LED 15 25 PD4/RXD1/IRRX1 PA7/T1OUT PC5/SCK/LED PA3/CTS0/X2OUT PD6/DE1 PA4/RXD0/IRRX0 PA5/TXD0/IRTX0 PC1/ANA5/C0INN/LED PC0/ANA4/C0INP/LED VSS VSS AVSS PD7/C0OUT PA2/DE0/X2IN PB0/AMPOUT/ANA0 PD1/C1INN PB2/AMPINP/ANA2 PC4/MOSI/LED 20 21 PA6/T1IN/T1OUT PD5/TXD1/IRTX1 Figure 4. Z8F2480, Z8F1680 and Z8F0880 in 40-Pin Dual Inline Package (PDIP) PS025016-1013 PRELIMINARY Pin Description Z8 Encore! XP® F1680 Series Product Specification PE6/T4CHD 33 34 PC2/SS/ANA6/LED PD2/C1INP PC3/MISO/LED PB2/AMPINP/ANA2 PB1/AMPINN/ANA1 PB0/AMPOUT/ANA0 PD1/C1INN PB5/VREF PB4/ANA7 PE5/T4CHC PB3/CLKIN/ANA3 13 23 22 28 PC0/ANA4/C0INP/LED PE0/T4IN AVDD VDD PA0/T0IN/T0OUT/XIN PA1/T0OUT/XOUT VSS PE4/T4CHB VSS 39 17 PD3/CTS1/C1OUT DBG PD0/RESET AVSS PE1/SCL PE2/SDA VDD 1 12 11 PC7/T2OUT/LED PC6/T2IN/T2OUT/LED PD4/RXD1/IRRX1 PC4/MOSI/LED PC5/SCK/LED PA7/T1OUT PD5/TXD1/IRTX1 PA6/T1IN/T1OUT PA5/TXD0/IRTX0 6 PD6/DE1 PA4/RXD0/IRRX0 44 PA2/DE0/X2IN PA3/CTS0/X2OUT PE3/T4CHA PD7/C0OUT PC1/ANA5/C0INN/LED Figure 5. Z8F2480, Z8F1680 and Z8F0880 in 44-Pin Low-Profile Quad Flat Package (LQFP) or Quad Flat No Lead (QFN) PS025016-1013 PRELIMINARY Pin Description Z8 Encore! XP® F1680 Series Product Specification 14 2.3. Signal Descriptions Table 4 describes the signals for each block on the F1680 Series MCU. To determine the signals available for specific package styles, see the Pin Configurations chapter on page 10. Table 4. Signal Descriptions Signal Mnemonic I/O Description General-Purpose I/O Ports A–E PA[7:0] I/O Port A: These pins are used for general-purpose I/O. PB[5:0] I/O Port B: These pins are used for GPIO. PC[7:0] I/O Port C: These pins are used for GPIO. PD[7:0] I/O Port D: These pins are used for GPIO. PD0 is output only. PE[6:0] I/O Port E: These pins are used for GPIO. LIN-UART Controllers TXD0/TXD1 O Transmit Data 0–1: These signals are the transmit output from the UART0/1 and IrDA0/1. RXD0/RXD1 I Receive Data 0–1: These signals are the receive input for the UART0/1 and IrDA0/1. CTS0/CTS1 I Clear To Send 0–1: These signals are the flow control input for the UART0/1. DE0/DE1 O Driver Enable 0–1: These signals allow automatic control of external RS-485 drivers. These signals are approximately the inverse of the TXE (Transmit Empty) bit in the UART Status 0/1 register. The DE0/1 signal can be used to ensure the external RS-485 driver is enabled when data is transmitted by the UART0/1. SCL I/O I2C Serial Clock: The I2C Master supplies this signal. If the F1680 Series MCU is the I2C Master, this pin is an output. If it is the I2C slave, this pin is an input. When the GPIO pin is configured as an alternate function to enable the SCL function, this pin is open-drain. SDA I/O Serial Data: This open-drain pin transfers data between the I2C and an external I2C Master/Slave. When the GPIO pin is configured as an alternate function to enable the SDA function, this pin is open-drain. I/O Slave Select: This signal can be an output or an input. If the F1680 Series MCU is the SPI master, this pin can be configured as the Slave Select output. If it is the SPI slave, this pin is the input slave select. I2C Controller ESPI Controller SS PS025016-1013 PRELIMINARY Pin Description Z8 Encore! XP® F1680 Series Product Specification 15 Table 4. Signal Descriptions (Continued) Signal Mnemonic I/O Description SCK I/O SPI Serial Clock: The SPI master supplies this signal. If the F1680 Series MCU is the SPI master, this pin is an output. If it is the SPI slave, this pin is an input. MOSI I/O Master Out Slave In: This signal is the data output from the SPI master device and the data input to the SPI slave device. MISO I/O Master In Slave Out: This pin is the data input to the SPI master device and the data output from the SPI slave device. T0OUT/T1OUT/ T2OUT O Timer Output 0–2: These signals are output from the timers. T0OUT/T1OUT/ T2OUT O Timer Complement Output 0–2: These signals are output from the timers in PWM DUAL OUTPUT Mode. T0IN/T1IN/T2IN I Timer Input 0–2: These signals are used as the capture, gating and counter inputs. The T0IN/T1IN/T2IN signal is multiplexed with T0OUT/T1OUT/ T2OUT signals. Timers Multi-Channel Timers TACHA, TACHB, TACHC, TACHD I/O Multi-channel timer Input/Output: These signals function as Capture input or Compare output for channels CHA, CHB, CHC and CHD. T4IN I Multi-channel Timer clock input: This signal allows external input to serve as the clock source for the Multi-channel timer. C0INP/C0INN, C1INP/C1INN I Comparator Inputs: These signals are positive and negative inputs to the comparator 0 and comparator 1. C0OUT/C1OUT O Comparator Outputs: These are the output from the comparator 0 and the comparator 1. ANA[7:0] I Analog Port: These signals are used as inputs to the ADC. The ANA0, ANA1 and ANA2 pins can also access the inputs and outputs of the integrated LowPower Operational Amplifier. VREF I/O ADC reference voltage input. Comparators Analog Low-Power Operational Amplifier AMPINP/AMPINN I Low-Power Operational Amplifier Inputs: If enabled, these pins drive the positive and negative amplifier inputs respectively. AMPOUT O Low-Power Operational Amplifier Output: If enabled, this pin is driven by the on-chip low-power operational amplifier. PS025016-1013 PRELIMINARY Pin Description Z8 Encore! XP® F1680 Series Product Specification 16 Table 4. Signal Descriptions (Continued) Signal Mnemonic I/O Description Oscillators XIN I External Crystal Input: The input pin to the crystal oscillator. A crystal can be connected between the pin and the XOUT pin to form the oscillator. In addition, this pin is used with external RC networks or external clock drivers to provide the system clock. XOUT O External Crystal Output: This pin is the output of the crystal oscillator. A crystal can be connected between it and the XIN pin to form the oscillator. X2IN I Watch Crystal Input: The input pin to the low-power 32 kHz oscillator. A watch crystal can be connected between the X2IN and the X2OUT pin to form the oscillator. X2OUT O Watch Crystal Output: This pin is the output from the low power 32 kHz oscillator. A watch crystal can be connected between the X2IN and the X2OUT pin to form the oscillator. I Clock Input Signal: This pin can be used to input a TTL-level signal to be used as the system clock. O Direct LED Drive Capability: All Port C pins have the capability to drive an LED without any other external components. These pins have programmable drive strengths set by the GPIO block. I/O Debug: This signal is the control and data input and output of the On-Chip Debugger. Caution: The DBG pin is open-drain and requires an external pull-up resistor to ensure proper operation. I/O RESET: Generates a Reset when asserted (driven Low). Also serves as a Reset indicator; the Z8 Encore! XP forces this pin Low when in Reset. This pin is open-drain and features an enabled internal pull-up resistor. Clock Input CLKIN LED Drivers LED On-Chip Debugger DBG Reset RESET Power Supply VDD I Digital Power Supply. AVDD I Analog Power Supply. VSS I Digital Ground. AVSS I Analog Ground. Note: The AVDD and AVSS signals are available only in 28-pin, 40-pin and 44-pin packages. PS025016-1013 PRELIMINARY Pin Description Z8 Encore! XP® F1680 Series Product Specification 17 2.4. Pin Characteristics Table 5 provides detailed information about the characteristics of each pin available on the F1680 Series MCU 20-, 28-, 40- and 44-pin devices. Data provided in Table 5 is sorted alphabetically by the pin symbol mnemonic. Table 5. Pin Characteristics (20-, 28-, 40- and 44-pin Devices) Active Low or Symbol Reset Active Mnemonic Direction Direction High Internal  Tristate Pull-up or Output Pull-down Schmitt Trigger Open Drain 5 V Input Output Tolerance AVDD N/A N/A N/A N/A N/A N/A N/A N/A AVSS N/A N/A N/A N/A N/A N/A N/A NA DBG I/O I N/A Yes Yes Yes Yes No PA[7:0] I/O I N/A Yes Programmable Yes pull-up Yes, Yes, 5 V programmab tolerant le inputs unless pullups are enabled PB[5:0] I/O I N/A Yes Programmable Yes pull-up Yes, Yes, 5 V programmab tolerant le inputs unless pullups are enabled PC[7:0] I/O I N/A Yes Programmable Yes pull-up Yes, Yes, 5 V programmab tolerant inputs le unless pullups are enabled PD[7:1] I/O I N/A Yes Programmable Yes pull-up Yes, Yes, 5 V programmab tolerant le inputs unless pullups are enabled PS025016-1013 PRELIMINARY Pin Description Z8 Encore! XP® F1680 Series Product Specification 18 Table 5. Pin Characteristics (20-, 28-, 40- and 44-pin Devices) (Continued) Active Low or Symbol Reset Active Mnemonic Direction Direction High Yes Schmitt Trigger Open Drain 5 V Input Output Tolerance PE[6:0] I/O I RESET/ PD0 I/O I/O (defaults to RESET) VDD N/A N/A N/A N/A N/A N/A VSS N/A N/A N/A N/A N/A N/A PS025016-1013 N/A Internal  Tristate Pull-up or Output Pull-down Programmable Yes pull-up Yes, Yes, 5 V programmab tolerant le inputs unless pullups are enabled Low (in Yes (PD0 Programmable Yes RESET only) for PD0; always mode) On for RESET Programmab Yes, 5 V le for PD0; tolerant always On inputs for RESET unless pullups are enabled PRELIMINARY Pin Description Z8 Encore! XP® F1680 Series Product Specification 19 Chapter 3. Address Space The eZ8 CPU can access the following three distinct address spaces: • The Register File contains addresses for general-purpose registers, eZ8 CPU, peripherals and GPIO port control registers • The Program Memory contains addresses for all memory locations having executable code and/or data • The Data Memory contains addresses for all memory locations that contain data only These three address spaces are covered briefly in the following sections. For more details about the eZ8 CPU and its address space, refer to the eZ8 CPU Core User Manual (UM0128), available for download at www.zilog.com. 3.1. Register File The Register File address space in the Z8 Encore!® MCU is 4 KB (4096 bytes). The Register File is composed of two sections: control registers and general-purpose registers. When instructions are executed, registers defined as sources are read and registers defined as destinations are written. The architecture of the eZ8 CPU allows all general-purpose registers to function as accumulators, address pointers, index registers, stack areas, or scratch pad memory. The upper 256 bytes of the 4 KB Register File address space are reserved for control of the eZ8 CPU, on-chip peripherals and the input/output ports. These registers are located at addresses F00h to FFFh. Some of the addresses within the 256 B control register sections are reserved (that is, unavailable). Reading from a reserved Register File address returns an undefined value. Zilog does not recommend writing to the reserved Register File addresses because doing so can produce unpredictable results. The on-chip Register RAM always begins at address 000h in the Register File address space. The F1680 Series MCU contains 1 KB or 2 KB of on-chip Register RAM. Reading from Register File addresses outside the available RAM addresses (and not within the control register address space) returns an undefined value. Writing to these Register File addresses produces no effect. In addition, the F1680 Series MCU contains 1 KB of on-chip Program RAM. Normally it is used as Program RAM and is present in the Program Memory address space (see the Program Memory section on page 20). However, it can also be used as additional Register RAM present in the Register File address space 800h–BFFh (1 KB Program RAM, 2 KB Register RAM), or 400h–7FFh (1 KB Program RAM, 1 KB Register RAM), if you do not PS025016-1013 PRELIMINARY Address Space Z8 Encore! XP® F1680 Series Product Specification 20 need to use this on-chip Program RAM to shadow Interrupt Service Routines (ISR). For details, see the PRAM_M section on page 278. 3.2. Program Memory The eZ8 CPU supports 64 KB of Program Memory address space. The F1680 Series MCU contains 8 KB to 24 KB of on-chip Flash memory in the Program Memory address space, depending on the device. In addition, the F1680 Series MCU contains up to 1 KB of on-chip Program RAM. The Program RAM is mapped in the Program Memory address space beyond the on-chip Flash memory. The Program RAM is entirely under user control and is meant to store interrupt service routines of high-frequency interrupts. Since interrupts bring the CPU out of lowpower mode, it is important to ensure that interrupts that occur very often use as low a current as possible. For battery operated systems, Program RAM based handling of highfrequency interrupts provides power savings by keeping the Flash block disabled. Program RAM (PRAM) is optimized for low-current operation and can be easily bootstrapped with interrupt code at power up. Reading from Program Memory addresses present outside the available Flash memory and PRAM addresses returns FFh. Writing to these unimplemented Program Memory addresses produces no effect. Table 6 describes the Program Memory maps for the F1680 Series MCU. Table 6. F1680 Series MCU Program Memory Maps Program Memory Address (Hex) Function Z8F2480 Device 0000–0001 Flash option bits 0002–0003 Reset vector 0004–0005 WDT interrupt vector 0006–0007 Illegal instruction trap 0008–0037 Interrupt vectors* 0038–003D Oscillator fail traps* 003E–5FFF Program Flash E000–E3FF 1 KB PRAM Note: *See Table 36 on page 69 for a list of interrupt vectors and traps. PS025016-1013 PRELIMINARY Address Space Z8 Encore! XP® F1680 Series Product Specification 21 Table 6. F1680 Series MCU Program Memory Maps (Continued) Program Memory Address (Hex) Function Z8F1680 Device 0000–0001 Flash option bits 0002–0003 Reset vector 0004–0005 WDT interrupt vector 0006–0007 Illegal instruction trap 0008–0037 Interrupt vectors* 0038–003D Oscillator fail traps* 003E–3FFF Program Flash E000–E3FF 1 KB PRAM Z8F0880 Device 0000–0001 Flash option bits 0002–0003 Reset vector 0004–0005 WDT interrupt vector 0006–0007 Illegal instruction trap 0008–0037 Interrupt vectors* 0038–003D Oscillator fail traps* 003E–1FFF Program Flash E000–E3FF 1 KB PRAM Note: *See Table 36 on page 69 for a list of interrupt vectors and traps. 3.3. Data Memory The F1680 Series MCU does not use the eZ8 CPU’s 64 KB Data Memory address space. 3.4. Flash Information Area Table 7 describes the F1680 Series MCU Flash Information Area. This 512-byte Information Area is accessed by setting bit 7 of the Flash Page Select Register to 1. When access is enabled, the Flash Information Area is mapped into the Program Memory and overlays the 512bytes at addresses FE00h to FFFFh. When the Information Area access is enabled, all reads from these Program Memory addresses return the Information Area data rather than the Program Memory data. Access to the Flash Information Area is read-only. PS025016-1013 PRELIMINARY Address Space Z8 Encore! XP® F1680 Series Product Specification 22 Table 7. F1680 Series MCU Flash Memory Information Area Map Program Memory Address (Hex) Function FE00–FE3F Zilog option bits FE40–FE53 Part Number: 20-character ASCII alphanumeric code Left-justified and filled with Fh FE54–FE5F Reserved FE60–FE7F Zilog calibration data (only use the first two bytes FE60 and FE61) FE80–FFFF Reserved PS025016-1013 PRELIMINARY Address Space Z8 Encore! XP® F1680 Series Product Specification 23 Chapter 4. Register Map Table 8 provides an address map to the register file contained in all Z8 Encore! XP F1680 Series devices. Not all devices and package styles in this product series support the ADC, nor all of the GPIO ports. Therefore, consider the registers for unimplemented peripherals to be reserved. Table 8. Register File Address Map Address (Hex) Register Description Mnemonic Reset (Hex)1 Page # General Purpose RAM Z8F2480 Device 000–7FF General-Purpose Register File RAM — XX 800–EFF Reserved2 — XX 000–7FF General-Purpose Register File RAM — XX 800–EFF Reserved2 — XX 000–3FF General-Purpose Register File RAM — XX 400–EFF Reserved2 — XX Z8F1680 Device Z8F0880 Device Special Purpose Registers Timer 0 F00 Timer 0 High Byte T0h 00 109 F01 Timer 0 Low Byte T0L 01 109 F02 Timer 0 Reload High Byte T0RH FF 110 F03 Timer 0 Reload Low Byte T0RL FF 110 F04 Timer 0 PWM0 High Byte T0PWM0h 00 110 F05 Timer 0 PWM0 Low Byte T0PWM0L 00 111 F06 Timer 0 Control 0 T0CTL0 00 112 F07 Timer 0 Control 1 T0CTL1 00 113 Notes: 1. XX=Undefined. 2. The Reserved space can be configured as General-Purpose Register File RAM depending on the user option bits (see the User Option Bits chapter on page 277) and the on-chip PRAM size (see the Ordering Information chapter on page 372). If the PRAM is programmed as General-Purpose Register File RAM on Reserved space, the starting address always begins immediately after the end of General-Purpose Register File RAM. PS025016-1013 PRELIMINARY Register Map Z8 Encore! XP® F1680 Series Product Specification 24 Table 8. Register File Address Map (Continued) Reset (Hex)1 Page # Address (Hex) Register Description Mnemonic F20 Timer 0 PWM1 High Byte T0PWM1h 00 111 F21 Timer 0 PWM1 Low Byte T0PWM1L 00 111 F22 Timer 0 Control 2 T0CTL2 00 117 F23 Timer 0 Status T0STA 00 118 F2C Timer 0 Noise Filter Control T0NFC 00 119 Timer 1 F08 Timer 1 High Byte T1h 00 109 F09 Timer 1 Low Byte T1L 01 109 F0A Timer 1 Reload High Byte T1RH FF 110 F0B Timer 1 Reload Low Byte T1RL FF 110 F0C Timer 1 PWM0 High Byte T1PWM0h 00 110 F0D Timer 1 PWM0 Low Byte T1PWM0L 00 111 F0E Timer 1 Control 0 T1CTL0 00 112 F0F Timer 1 Control 1 T1CTL1 00 113 F24 Timer 1 PWM1 High Byte T1PWM1h 00 111 F25 Timer 1 PWM1 Low Byte T1PWM1L 00 111 F26 Timer 1 Control 2 T1CTL2 00 117 F27 Timer 1 Status T1STA 00 118 F2D Timer 1 Noise Filter Control T1NFC 00 119 Timer 2 F10 Timer 2 High Byte T2h 00 109 F11 Timer 2 Low Byte T2L 01 110 F12 Timer 2 Reload High Byte T2RH FF 110 F13 Timer 2 Reload Low Byte T2RL FF 110 F14 Timer 2 PWM0 High Byte T2PWM0h 00 110 F15 Timer 2 PWM0 Low Byte T2PWM0L 00 111 F16 Timer 2 Control 0 T2CTL0 00 112 Notes: 1. XX=Undefined. 2. The Reserved space can be configured as General-Purpose Register File RAM depending on the user option bits (see the User Option Bits chapter on page 277) and the on-chip PRAM size (see the Ordering Information chapter on page 372). If the PRAM is programmed as General-Purpose Register File RAM on Reserved space, the starting address always begins immediately after the end of General-Purpose Register File RAM. PS025016-1013 PRELIMINARY Register Map Z8 Encore! XP® F1680 Series Product Specification 25 Table 8. Register File Address Map (Continued) Address (Hex) Register Description F17 Timer 2 Control 1 F28 Mnemonic Reset (Hex)1 Page # T2CTL1 00 113 Timer 2 PWM1 High Byte T2PWM1h 00 111 F29 Timer 2 PWM1 Low Byte T2PWM1L 00 111 F2A Timer 2 Control 2 T2CTL2 00 117 F2B Timer 2 Status T2STA 00 118 F2E Timer 2 Noise Filter Control T2NFC 00 119 F2F–F3F Reserved — XX LIN UART0 Transmit Data U0TXD XX 163 LIN UART0 Receive Data U0RXD XX 164 LIN UART0 Status 0—Standard UART Mode U0STAT0 0000011Xb 165 LIN UART0 Status 0—LIN Mode U0STAT0 00000110b 166 F42 LIN UART0 Control 0 U0CTL0 00 170 F43 LIN UART0 Control 1—Multiprocessor Control U0CTL1 00 172 LIN UART0 Control 1—Noise Filter Control U0CTL1 00 174 LIN UART0 Control 1—LIN Control U0CTL1 00 175 F44 LIN UART0 Mode Select and Status U0MDSTAT 00 168 F45 UART0 Address Compare U0ADDR 00 177 F46 UART0 Baud Rate High Byte U0BRH FF 177 F47 UART0 Baud Rate Low Byte U0BRL FF 178 LIN UART1 Transmit Data U1TXD XX 163 LIN UART1 Receive Data U1RXD XX 164 LIN UART1 Status 0—Standard UART Mode U1STAT0 0000011Xb 165 LIN UART1 Status 0—LIN Mode U1STAT0 00000110b 166 LIN UART1 Control 0 U1CTL0 00 170 LIN UART 0 F40 F41 LIN UART 1 F48 F49 F4A Notes: 1. XX=Undefined. 2. The Reserved space can be configured as General-Purpose Register File RAM depending on the user option bits (see the User Option Bits chapter on page 277) and the on-chip PRAM size (see the Ordering Information chapter on page 372). If the PRAM is programmed as General-Purpose Register File RAM on Reserved space, the starting address always begins immediately after the end of General-Purpose Register File RAM. PS025016-1013 PRELIMINARY Register Map Z8 Encore! XP® F1680 Series Product Specification 26 Table 8. Register File Address Map (Continued) Mnemonic Reset (Hex)1 Page # Address (Hex) Register Description F4B LIN UART1 Control 1—Multiprocessor Control U1CTL1 00 172 LIN UART1 Control 1—Noise Filter Control U1CTL1 00 174 LIN UART1 Control 1—LIN Control U1CTL1 00 175 F4C LIN UART1 Mode Select and Status U1MDSTAT 00 168 F4D UART1 Address Compare U1ADDR 00 177 F4E UART1 Baud Rate High Byte U1BRH FF 177 F4F UART1 Baud Rate Low Byte U1BRL FF 178 I2CDATA 00 244 I2CISTAT 80 245 I2C F50 I2C Data 2 F51 I C Interrupt Status F52 I2C Control I2CCTL 00 247 F53 I2C Baud Rate High Byte I2CBRH FF 248 F54 2 I C Baud Rate Low Byte I2CBRL FF 249 2 F55 I C State I2CSTATE 02 251 F56 I2C Mode I2CMODE 00 252 I2CSLVAD 00 255 — XX 2 F57 I C Slave Address F58-F5F Reserved Enhanced Serial Peripheral Interface (ESPI) F60 ESPI Data ESPIDATA XX 214 F61 ESPI Transmit Data Command ESPITDCR 00 214 F62 ESPI Control ESPICTL 00 215 F63 ESPI Mode ESPIMODE 00 217 F64 ESPI Status ESPISTAT 01 219 F65 ESPI State ESPISTATE 00 220 F66 ESPI Baud Rate High Byte ESPIBRH FF 220 F67 ESPI Baud Rate Low Byte ESPIBRL FF 220 F68–F6F Reserved — XX Notes: 1. XX=Undefined. 2. The Reserved space can be configured as General-Purpose Register File RAM depending on the user option bits (see the User Option Bits chapter on page 277) and the on-chip PRAM size (see the Ordering Information chapter on page 372). If the PRAM is programmed as General-Purpose Register File RAM on Reserved space, the starting address always begins immediately after the end of General-Purpose Register File RAM. PS025016-1013 PRELIMINARY Register Map Z8 Encore! XP® F1680 Series Product Specification 27 Table 8. Register File Address Map (Continued) Address (Hex) Register Description Mnemonic Reset (Hex)1 Page # Analog-to-Digital Converter (ADC) F70 ADC Control 0 ADCCTL0 00 189 F71 ADC Raw Data High Byte ADCRD_H 80 191 F72 ADC Data High Byte ADCD_H XX 191 F73 ADC Data Low Bits ADCD_L XX 192 F74 ADC Sample Settling Time ADCSST FF 193 F75 Sample Time ADCST XX 194 F76 ADC Clock Prescale Register ADCCP 00 195 F77–F7F Reserved — XX PWRCTL0 80 — XX LEDEN 00 66 Low-Power Control F80 Power Control 0 F81 Reserved 44 LED Controller F82 LED Drive Enable F83 LED Drive Level High Bit LEDLVLH 00 67 F84 LED Drive Level Low Bit LEDLVLL 00 67 F85 Reserved — XX Oscillator Control F86 Oscillator Control 0 OSCCTL0 A0 319 F87 Oscillator Control 1 OSCCTL1 00 320 F88–F8F Reserved Comparator 0 Control CMP0 14 257 F91 Comparator 1 Control CMP1 14 258 F92–F9F Reserved — XX Comparator 0 F90 Comparator 1 Notes: 1. XX=Undefined. 2. The Reserved space can be configured as General-Purpose Register File RAM depending on the user option bits (see the User Option Bits chapter on page 277) and the on-chip PRAM size (see the Ordering Information chapter on page 372). If the PRAM is programmed as General-Purpose Register File RAM on Reserved space, the starting address always begins immediately after the end of General-Purpose Register File RAM. PS025016-1013 PRELIMINARY Register Map Z8 Encore! XP® F1680 Series Product Specification 28 Table 8. Register File Address Map (Continued) Address (Hex) Register Description Mnemonic Reset (Hex)1 Page # Multi-Channel Timer FA0 MCT High Byte MCTH 00 130 FA1 MCT Low Byte MCTL 00 130 FA2 MCT Reload High Byte MCTRH FF 131 FA3 MCT Reload Low Byte MCTRL FF 131 FA4 MCT Subaddress MCTSA XX 132 FA5 MCT Subregister 0 MCTSR0 XX 132 FA6 MCT Subregister 1 MCTSR1 XX 132 FA7 MCT Subregister 2 MCTSR2 XX 132 FA8–FBF Reserved — XX IRQ0 00 73 Interrupt Controller FC0 Interrupt Request 0 FC1 IRQ0 Enable High Bit IRQ0ENH 00 76 FC2 IRQ0 Enable Low Bit IRQ0ENL 00 77 FC3 Interrupt Request 1 IRQ1 00 74 FC4 IRQ1 Enable High Bit IRQ1ENH 00 78 FC5 IRQ1 Enable Low Bit IRQ1ENL 00 79 FC6 Interrupt Request 2 IRQ2 00 75 FC7 IRQ2 Enable High Bit IRQ2ENH 00 80 FC8 IRQ2 Enable Low Bit IRQ2ENL 00 81 FC9–FCC Reserved — XX FCD Interrupt Edge Select IRQES 00 82 FCE Shared Interrupt Select IRQSS 00 82 FCF Interrupt Control IRQCTL 00 83 FD0 Port A Address PAADDR 00 58 FD1 Port A Control PACTL 00 60 GPIO Port A Notes: 1. XX=Undefined. 2. The Reserved space can be configured as General-Purpose Register File RAM depending on the user option bits (see the User Option Bits chapter on page 277) and the on-chip PRAM size (see the Ordering Information chapter on page 372). If the PRAM is programmed as General-Purpose Register File RAM on Reserved space, the starting address always begins immediately after the end of General-Purpose Register File RAM. PS025016-1013 PRELIMINARY Register Map Z8 Encore! XP® F1680 Series Product Specification 29 Table 8. Register File Address Map (Continued) Address (Hex) Register Description FD2 Port A Input Data FD3 Port A Output Data Mnemonic Reset (Hex)1 Page # PAIN XX 60 PAOUT 00 60 GPIO Port B FD4 Port B Address PBADDR 00 58 FD5 Port B Control PBCTL 00 60 FD6 Port B Input Data PBIN XX 60 FD7 Port B Output Data PBOUT 00 60 GPIO Port C FD8 Port C Address PCADDR 00 58 FD9 Port C Control PCCTL 00 60 FDA Port C Input Data PCIN XX 60 FDB Port C Output Data PCOUT 00 60 GPIO Port D FDC Port D Address PDADDR 00 58 FDD Port D Control PDCTL 00 60 FDE Port D Input Data PDIN XX 60 FDF Port D Output Data PDOUT 00 60 GPIO Port E FE0 Port E Address PEADDR 00 58 FE1 Port E Control PECTL 00 60 FE2 Port E Input Data PEIN XX 60 FE3 Port E Output Data PEOUT 00 60 FE4–FEF Reserved — XX RSTSTAT XX — XX Reset FF0 Reset Status FF1 Reserved 40 Notes: 1. XX=Undefined. 2. The Reserved space can be configured as General-Purpose Register File RAM depending on the user option bits (see the User Option Bits chapter on page 277) and the on-chip PRAM size (see the Ordering Information chapter on page 372). If the PRAM is programmed as General-Purpose Register File RAM on Reserved space, the starting address always begins immediately after the end of General-Purpose Register File RAM. PS025016-1013 PRELIMINARY Register Map Z8 Encore! XP® F1680 Series Product Specification 30 Table 8. Register File Address Map (Continued) Address (Hex) Register Description Mnemonic Reset (Hex)1 Page # Watchdog Timer FF2 Watchdog Timer Reload High Byte WDTH FF 143 FF3 Watchdog Timer Reload Low Byte WDTL FF 143 FF4–FF5 Reserved — XX TRMADR 00 281 TRMDR XX 281 Flash Control FCTL 00 272 Flash Status FSTAT 00 272 FPS 00 273 FPROT 00 274 Trim Bit Control FF6 Trim Bit Address FF7 Trim Data Flash Memory Controller FF8 FF9 Flash Page Select Flash Sector Protect FFA Flash Programming Frequency High Byte FFREQH 00 275 FFB Flash Programming Frequency Low Byte FFREQL 00 275 refer to the eZ8 CPU Core User Manual (UM0128) eZ8 CPU FFC Flags — XX FFD Register Pointer RP XX FFE Stack Pointer High Byte SPH XX FFF Stack Pointer Low Byte SPL XX Notes: 1. XX=Undefined. 2. The Reserved space can be configured as General-Purpose Register File RAM depending on the user option bits (see the User Option Bits chapter on page 277) and the on-chip PRAM size (see the Ordering Information chapter on page 372). If the PRAM is programmed as General-Purpose Register File RAM on Reserved space, the starting address always begins immediately after the end of General-Purpose Register File RAM. PS025016-1013 PRELIMINARY Register Map Z8 Encore! XP® F1680 Series Product Specification 31 Chapter 5. Reset, Stop Mode Recovery and Low-Voltage Detection The Reset Controller within the F1680 Series MCU controls Reset and Stop Mode Recovery operations and provides indication of low-voltage supply conditions. During the operation, the following events cause a Reset: • • • Power-On Reset (POR) • External RESET pin assertion (when the alternate RESET function is enabled by the GPIO register) • On-Chip Debugger initiated Reset (OCDCTL[0] set to 1) Voltage Brown-Out (VBO) protection Watchdog Timer (WDT) time-out (when configured by the WDT_RES Flash option bit to initiate a Reset) When the device is in STOP Mode, a Stop Mode Recovery is initiated by each of the following: • • • Watchdog Timer time-out GPIO Port input pin transition on an enabled Stop Mode Recovery source Interrupt from a timer or comparator enabled for STOP Mode operation The low-voltage detection circuitry on the device features the following: • • 5.1. The low-voltage detection threshold level is user-defined It generates an interrupt when the supply voltage drops below a user-defined level Reset Types The F1680 Series MCU provides various types of Reset operation. Stop Mode Recovery is considered a form of Reset. Table 9 lists the types of Reset and their operating characteristics. The System Reset is longer, if the external crystal oscillator is enabled by the Flash option bits allowing additional time for oscillator start-up. PS025016-1013 PRELIMINARY Reset, Stop Mode Recovery and Low-Voltage Z8 Encore! XP® F1680 Series Product Specification 32 Table 9. Reset and Stop Mode Recovery Characteristics and Latency Reset Characteristics and Latency Reset Type Control Registers eZ8 CPU System Reset  (non-POR Reset) Reset (as applicable) Reset 68 Internal Precision Oscillator Cycles after IPO starts up System Reset  (POR Reset) Reset (as applicable) Reset 68 Internal Precision Oscillator Cycles + 50 ms Wait time System Reset with Crystal Oscillator Enabled Reset (as applicable) Reset 568–10068 Internal Precision Oscillator Cycles after IPO starts up; see Table 141 on page 280 for a description of the EXTLTMG user option bit. Stop Mode Recovery Unaffected, except RSTSTAT and OSCCTL registers 4 Internal Precision Oscillator Cycles after IPO starts up Reset Reset Latency (Delay) During a System Reset or Stop Mode Recovery, the Internal Precision Oscillator (IPO) requires 4 µs to start up. When the reset type is a System Reset, the F1680 Series MCU is held in Reset for 68 IPO cycles. If the crystal oscillator is enabled in Flash option bits, the Reset period is increased to 568–10068 IPO cycles. For more details, see Table 141 on page 280 for a description of the EXTLTMG user option bit. When the reset type is a Stop Mode Recovery, the F1680 Series MCU goes to NORMAL Mode immediately after 4 IPO cycles. The total Stop Mode Recovey delay is less than 6 µs. When a Reset occurs due to a VBO condition, this delay is measured from the time the supply voltage first exceeds the VBO level (discussed later in this chapter). When a Reset occurs due to a POR condition, this delay is measured from the time that the supply voltage first exceeds the POR level. If the external pin reset remains asserted at the end of the Reset period, the device remains in reset until the pin is deasserted. Note: After a Stop Mode Recovery, the external crystal oscillator is unstable. Use software to wait until it is stable before you can use it as main clock. At the beginning of Reset, all GPIO pins are configured as inputs with pull-up resistor disabled, except PD0 that is shared with the Reset pin. On Reset, the Port D0 pin is configured as a bidirectional open-drain Reset. The pin is internally driven Low during port reset, after which the user code can reconfigure this pin as a general-purpose output. During Reset, the eZ8 CPU and on-chip peripherals are idle; however, the on-chip crystal oscillator and WDT oscillator continue to function. PS025016-1013 PRELIMINARY Reset, Stop Mode Recovery and Low-Voltage Z8 Encore! XP® F1680 Series Product Specification 33 On Reset, control registers within the Register File that have a defined Reset value are loaded with their Reset values. Other control registers (including the Stack Pointer, Register Pointer and Flags) and general-purpose RAM are not initialized and undefined following Reset. The eZ8 CPU fetches the Reset vector at Program Memory addresses 0002h and 0003h and loads that value into the Program Counter. Program execution begins at the Reset vector address. Because the control registers are reinitialized by a System Reset, the system clock after reset is always the 11 MHz IPO. User software must reconfigure the oscillator control block such that the correct system clock source is enabled and selected. 5.2. Reset Sources Table 10 lists the possible sources of a System Reset. Table 10. Reset Sources and Resulting Reset Type Operating Mode Reset Source Special Conditions NORMAL or  HALT Mode Power-On Reset Reset delay begins after supply voltage exceeds POR level Voltage Brown-Out Reset delay begins after supply voltage exceeds VBO level Watchdog Timer time-out when configured for Reset None RESET pin assertion All reset pulses less than three system clocks in width are ignored, see the Electrical Characteristics chapter on page 349. On-Chip Debugger initiated Reset System Reset, except the OCD is unaffected (OCDCTL[0] set to 1) by reset STOP Mode PS025016-1013 Power-On Reset Reset delay begins after supply voltage exceeds POR level Voltage Brown-Out Reset delay begins after supply voltage exceeds VBO level RESET pin assertion All reset pulses less than the specified analog delay is ignored, see the Electrical Characteristics chapter on page 349. DBG pin driven Low None PRELIMINARY Reset, Stop Mode Recovery and Low-Voltage Z8 Encore! XP® F1680 Series Product Specification 34 5.2.1. Power-On Reset Each device in the Z8 Encore! XP F1680 Series contains an internal Power-On Reset (POR) circuit. The POR circuit monitors the supply voltage and holds the whole device in the Reset state until the supply voltage reaches a safe circuit operating level when the device is powered on. After power on, the POR circuit keeps idle until the supply voltage drops below VTH voltage. Figure 7 on page 35 displays this POR timing. After the F1680 Series MCU exits the POR state, the eZ8 CPU fetches the Reset vector. Following this POR, the POR/VBO status bit in the Reset Status Register is set to 1. For the POR threshold voltage (VPOR) and POR start voltage VTH , see the Electrical Characteristics chapter on page 349. VDD = 3.3 V VPOR VDD = 0.0V Program Execution VTH Internal Precision Oscillator Crystal Oscillator Oscillator Start-up Internal RESET signal 50 ms Delay POR counter delay optional XTAL counter delay Internal POR Reset Notes 1. Not to Scale. 2. Internal Reset and POR Reset are active Low. undefined Figure 6. Power-On Reset Operation PS025016-1013 PRELIMINARY Reset, Stop Mode Recovery and Low-Voltage Z8 Encore! XP® F1680 Series Product Specification 35 V VCC VCC(min) VPOR POR POR No POR VTH t(POR_DELAY) t(POR_DELAY) POR Reset Figure 7. Power-On Reset Timing 5.2.2. Voltage Brown-Out Reset The F1680 Series MCU provides a VBO Reset feature for low-voltage protection. The VBO circuit has a preset threshold voltage (VVBO) with a hysteresis of VHYS. The VBO circuit will monitor the power supply voltage if the VBO is enabled. When VBO Reset circuit detects the power supply voltage falls below the threshold voltage VVBO, the VBO resets the device by pulling the POR Reset from 1 to 0. The VBO will hold the POR Reset until the power supply voltage goes above the VVBO + (VVBO + VHYS) and then the VBO Reset is released. The device progresses through a full System Reset sequence, just like power-on case. Following this System Reset sequence, the POR/VBO status bit in the Reset Status (RSTSTAT) register is set to 1. Figure 8 on page 36 displays VBO Reset operation. For VBO threshold voltages (VVBO) and VBO hysteresis (VHYS), see the Electrical Characteristics chapter on page 349. The VBO circuit is either enabled or disabled during STOP Mode. VBO circuit operation is controlled by both the VBO_AO Flash option bit and the Power Control Register bit4. For more details, see the Flash Option Bits chapter on page 276 and the Power Control Register Definitions section on page 44. PS025016-1013 PRELIMINARY Reset, Stop Mode Recovery and Low-Voltage Z8 Encore! XP® F1680 Series Product Specification 36 VDD = 3.3 V VDD = 3.3 V VVBO+ VVBO Program Execution Voltage Brown-Out Program Execution WDT Clock System Clock Internal Reset Signal POR counter delay Internal VBO Reset VBO delay: pulse rejection Note: Not to Scale Figure 8. Voltage Brown-Out Reset Operation 5.2.3. Watchdog Timer Reset If the device is operating in NORMAL or STOP modes, the WDT initiates a System Reset at time-out if the WDT_RES Flash option bit is programmed to 1 (which is the unprogrammed state of the WDT_RES Flash option bit). If the bit is programmed to 0, it configures the WDT to cause an interrupt, not a System Reset at time-out. The WDT status bit in the Reset Status Register is set to signify that the reset was initiated by the WDT. PS025016-1013 PRELIMINARY Reset, Stop Mode Recovery and Low-Voltage Z8 Encore! XP® F1680 Series Product Specification 37 5.2.4. External Reset Input The RESET pin has a Schmitt-triggered input and an internal pull-up resistor. When the RESET pin is asserted for a minimum of four system clock cycles, the device progresses through the System Reset sequence. Because of the possible asynchronicity of the system clock and reset signals, the required reset duration can be as short as three clock periods and as long as four. A reset pulse three clock cycles in duration might trigger a Reset; a pulse four cycles in duration always triggers a Reset. While the RESET input pin is asserted Low, the F1680 Series MCU remains in the Reset state. If the RESET pin is held Low beyond the System Reset time-out, the device exits the Reset state on the system clock rising edge following RESET pin deassertion. Following a System Reset initiated by the external RESET pin, the EXT status bit in the RSTSTAT Register is set to 1. 5.2.5. External Reset Indicator During System Reset or when enabled by the GPIO logic (see the Port A–E Control Registers section on page 60), the RESET pin functions as an open-drain (active Low) reset mode indicator in addition to the input functionality. This Reset output feature allows the F1680 Series MCU to reset other components to which it is connected, even if that reset is caused by internal sources such as POR, VBO, or WDT events. After an internal Reset event occurs, the internal circuitry begins driving the RESET pin Low. The RESET pin is held Low by the internal circuitry until the appropriate delay listed in Table 9 on page 32 has elapsed. 5.2.6. On-Chip Debugger Initiated Reset A POR can be initiated using the OCD by setting the RST bit in the OCD Control Register. The OCD block is not reset, but the rest of the chip goes through a normal System Reset. The RST bit automatically clears during the system reset. Following the System Reset the POR bit in the WDT Control Register is set. 5.3. Stop Mode Recovery STOP Mode is entered by execution of a stop instruction by the eZ8 CPU. For detailed STOP Mode information, see the Low-Power Modes section on page 42. During Stop Mode Recovery, the CPU is held in reset for 4 IPO cycles. Stop Mode Recovery does not affect On-chip registers other than the Reset Status (RSTSTAT) register and the Oscillator Control Register (OSCCTL). After any Stop Mode Recovery, the IPO is enabled and selected as the system clock. If another system clock source is required or IPO disabling is required, the Stop Mode Recovery code must PS025016-1013 PRELIMINARY Reset, Stop Mode Recovery and Low-Voltage Z8 Encore! XP® F1680 Series Product Specification 38 reconfigure the oscillator control block such that the correct system clock source is enabled and selected. The eZ8 CPU fetches the Reset vector at Program Memory addresses 0002h and 0003h and loads that value into the Program Counter. Program execution begins at the Reset vector address. Following Stop Mode Recovery, the stop bit in the Reset Status Register is set to 1. Table 11 lists the Stop Mode Recovery sources and resulting actions. The text following provides more detailed information about each of the Stop Mode Recovery sources. Table 11. Stop Mode Recovery Sources and Resulting Action Operating Mode STOP Mode Stop Mode Recovery Source Action Watchdog Timer time-out when configured Stop Mode Recovery for Reset Watchdog Timer time-out when configured Stop Mode Recovery followed by interrupt for interrupt (if interrupts are enabled) Interrupt from Timer enabled for STOP Mode operation Stop Mode Recovery followed by interrupt (if interrupts are enabled) Interrupt from Comparator enabled for STOP Mode operation Stop Mode Recovery followed by interrupt (if interrupts are enabled) Data transition on any GPIO port pin enabled as a Stop Mode Recovery source Stop Mode Recovery Assertion of external RESET Pin System Reset Debug Pin driven Low System Reset 5.3.1. Stop Mode Recovery Using Watchdog Timer Time-Out If the WDT times out during STOP Mode, the device undergoes a Stop Mode Recovery sequence. In the Reset Status Register, the WDT and stop bits are set to 1. If the WDT is configured to generate an interrupt on time-out and the F1680 Series MCU is configured to respond to interrupts. The eZ8 CPU services the WDT interrupt request following the normal Stop Mode Recovery sequence. 5.3.2. Stop Mode Recovery Using Timer Interrupt If a Timer with 32K crystal enabled for STOP Mode operation interrupts during STOP Mode, the device undergoes a Stop Mode Recovery sequence. In the Reset Status Register, the stop bit is set to 1. If the F1680 Series MCU is configured to respond to interrupts, the PS025016-1013 PRELIMINARY Reset, Stop Mode Recovery and Low-Voltage Z8 Encore! XP® F1680 Series Product Specification 39 eZ8 CPU services the Timer interrupt request following the normal Stop Mode Recovery sequence. 5.3.3. Stop Mode Recovery Using Comparator Interrupt If Comparator enabled for STOP Mode operation interrupts during STOP Mode, the device undergoes a Stop Mode Recovery sequence. In the Reset Status Register, the stop bit is set to 1. If the F1680 Series MCU is configured to respond to interrupts, the eZ8 CPU services the comparator interrupt request following the normal Stop Mode Recovery sequence. 5.3.4. Stop Mode Recovery Using GPIO Port Pin Transition Each of the GPIO port pins can be configured as a Stop Mode Recovery input source. On any GPIO pin enabled as a Stop Mode Recovery source, a change in the input pin value (from High to Low or from Low to High) initiates Stop Mode Recovery. In the Reset Status Register, the stop bit is set to 1. Caution: In STOP Mode, the GPIO Port Input Data registers (PxIN) are disabled. The Port Input Data registers record the Port transition only if the signal stays on the Port pin until the end of the Stop Mode Recovery delay. As a result, short pulses on the Port pin can initiate Stop Mode Recovery without being written to the Port Input Data Register or without initiating an interrupt (if enabled for that pin). 5.3.5. Stop Mode Recovery Using External RESET Pin When the F1680 Series MCU is in STOP Mode and the external RESET pin is driven Low, a System Reset occurs. Because of a glitch filter operating on the RESET pin, the Low pulse must be greater than the minimum width specified, or it is ignored. For details, see the Electrical Characteristics chapter on page 349. 5.4. Low-Voltage Detection In addition to the VBO Reset described earlier, it is also possible to generate an interrupt when the supply voltage drops below a user-selected value. For more details about the available Low-Voltage Detection (LVD) threshold levels, see the Trim Option Bits at Address 0000H (TTEMP0) section on page 282. When the supply voltage drops below the LVD threshold, the LVD bit of the RSTSTAT Register is set to 1. This bit remains 1 until the low-voltage condition elapses. Reading or PS025016-1013 PRELIMINARY Reset, Stop Mode Recovery and Low-Voltage Z8 Encore! XP® F1680 Series Product Specification 40 writing this bit does not clear it. The LVD circuit can also generate an interrupt when enabled (see the Interrupt Vectors and Priority section on page 71). The LVD is not latched, so enabling the interrupt is the only way to guarantee detection of a transient lowvoltage event. The LVD circuit is either enabled or disabled by the Power Control Register bit 4. For more details, see the Power Control Register Definitions section on page 44. 5.5. Reset Register Definitions The following sections define the Reset registers. 5.5.0.1. Reset Status Register The Reset Status (RSTSTAT) Register, shown in Table 12, is a read-only register that indicates the source of the most recent Reset event, Stop Mode Recovery event and/or WDT time-out. Reading this register resets the upper 4 bits to 0. This register shares its address with the Reset Status Register, which is write-only. Table 12. Reset Status Register (RSTSTAT) Bits 7 6 5 4 Field POR/VBO STOP WDT EXT See Table 13 Reset R R/W R R 3 2 1 Reserved 0 LVD 0 0 0 0 0 R R R R R FF0h Address Bit Description [7] POR/VBO Power-On initiated VBO Reset or general VBO Reset Indicator If this bit is set to 1, a POR or VBO Reset event occurs. This bit is reset to 0, if a WDT timeout or Stop Mode Recovery occurs. This bit is also reset to 0 when the register is read. [6] STOP Stop Mode Recovery Indicator If this bit is set to 1, a Stop Mode Recovery occurs. If the STOP and WDT bits are both set to 1, the Stop Mode Recovery occurs because of a WDT time-out. If the stop bit is 1 and the WDT bit is 0, the Stop Mode Recovery is not caused by a WDT time-out. This bit is reset by Power-On Reset or WDT time-out that occurred while not in STOP Mode. Reading this register also resets this bit. [5] WDT Watchdog Timer time-out Indicator If this bit is set to 1, a WDT time-out occurs. A POR resets this pin. A Stop Mode Recovery from a change in an input pin also resets this bit. Reading this register resets this bit. This Read must occur before clearing the WDT interrupt. PS025016-1013 PRELIMINARY Reset, Stop Mode Recovery and Low-Voltage Z8 Encore! XP® F1680 Series Product Specification 41 Bit Description (Continued) [4] EXT External Reset Indicator If this bit is set to 1, a Reset initiated by the external RESET pin occurs. A POR or a Stop Mode Recovery from a change in an input pin resets this bit. Reading this register resets this bit. [3:1] Reserved; must be 0. [0] LVD Low-Voltage Detection Indicator If this bit is set to 1 the current state of the supply voltage is below the low-voltage detection threshold. This value is not latched but is a real-time indicator of the supply voltage level. Table 13. Reset Status Per Event Reset or Stop Mode Recovery Event POR STOP WDT EXT Power-On Reset or VBO Reset 1 0 0 0 Reset using RESET pin assertion 0 0 0 1 Reset using Watchdog Timer time-out 0 0 1 0 Reset using the On-Chip Debugger (OCTCTL[1] set to 1) 1 0 0 0 Reset from STOP Mode using DBG Pin driven Low 1 0 0 0 Stop Mode Recovery using GPIO pin transition 0 1 0 0 Stop Mode Recovery using Watchdog Timer time-out 0 1 1 0 PS025016-1013 PRELIMINARY Reset, Stop Mode Recovery and Low-Voltage Z8 Encore! XP® F1680 Series Product Specification 42 Chapter 6. Low-Power Modes The Z8 Encore! XP F1680 Series products have power-saving features. The highest level of power reduction is provided by the STOP Mode. The next lower level of power reduction is provided by the HALT Mode. Further power savings can be implemented by disabling individual peripheral blocks while in NORMAL Mode. 6.1. STOP Mode Executing the eZ8 CPU’s Stop instruction places the device into STOP Mode. In STOP Mode, the operating characteristics are: PS025016-1013 • Primary crystal oscillator and internal precision oscillator are stopped; XIN and XOUT  (if previously enabled) are disabled and PA0/PA1 reverts to the states programmed by the GPIO registers • • • • System clock is stopped • • • If enabled, the Watchdog Timer (WDT) logic continues operating • If enabled for operation in STOP Mode by the associated Flash option bit, the VBO protection circuit continues operating; the low-voltage detection circuit continues to operate if enabled by the Power Control Register • Low-Power Operational Amplifier and comparator continue to operate if enabled by the Power Control Register • All other on-chip peripherals are idle eZ8 CPU is stopped Program counter (PC) stops incrementing Watchdog Timer’s internal RC oscillator continues operating if enabled by the Oscillator Control Register If enabled, the 32 kHz secondary oscillator continues operating If enabled for operation in STOP Mode, the Timer logic continues to operate with 32 kHz secondary oscillator as the Timer clock source PRELIMINARY Low-Power Modes Z8 Encore! XP® F1680 Series Product Specification 43 To minimize current in STOP Mode, all GPIO pins which are configured as digital inputs must be driven to one of the supply rails (VDD or GND). The device is brought out of STOP Mode using Stop Mode Recovery. For more details about Stop Mode Recovery, see the Reset, Stop Mode Recovery and Low-Voltage Detection chapter on page 31. 6.2. HALT Mode Executing the eZ8 CPU’s HALT instruction places the device into HALT Mode. In HALT Mode, the operating characteristics are: • • • • • • • • Primary oscillator is enabled and continues to operate System clock is enabled and continues to operate eZ8 CPU is stopped Program counter (PC) stops incrementing WDT’s internal RC oscillator continues to operate If enabled, the WDT continues to operate If enabled, the 32 kHz secondary oscillator for Timers continues to operate All other on-chip peripherals continue to operate The eZ8 CPU can be brought out of HALT Mode by any of the following operations: • • • • • Interrupt Watchdog Timer time-out (Interrupt or Reset) Power-On Reset Voltage Brown-Out Reset External RESET pin assertion To minimize current in HALT Mode, all GPIO pins which are configured as inputs must be driven to one of the supply rails (VDD or GND). 6.3. Peripheral-Level Power Control In addition to the STOP and HALT modes, it is possible to disable each peripheral on each of the Z8 Encore! XP F1680 Series devices. Disabling a given peripheral minimizes its power consumption. PS025016-1013 PRELIMINARY Low-Power Modes Z8 Encore! XP® F1680 Series Product Specification 44 6.4. Power Control Register Definitions The following sections describe the power control registers. 6.4.0.1. Power Control Register 0 Each bit of the following registers disables a peripheral block, either by gating its system clock input or by removing power from the block. The default state of the low-power operational amplifier is OFF. To use the low-power operational amplifier, clear the TRAM bit by turning it ON. Clearing this bit might interfere with normal ADC measurements on ANA0 (the LPO output). This bit enables the amplifier even in STOP Mode. If the amplifier is not required in STOP Mode, disable it. Failure to perform this results in STOP Mode currents greater than specified. This register is only reset during a POR sequence; other system reset events do not affect it. Note: Table 14. Power Control Register 0 (PWRCTL0) Bits 7 Field TRAM Reset 1 0 R/W R/W R/W 6 5 4 3 2 1 0 LVD/VBO TEMP Reserved COMP0 COMP1 0 0 0 0 0 0 R/W R/W R/W R/W R/W R/W Reserved Address F80h Bit Description [7] TRAM Low-Power Operational Amplifier Disable 0 = Low-Power Operational Amplifier is enabled (this applies even in STOP Mode). 1 = Low-Power Operational Amplifier is disabled. [6:5] Reserved; must be 0. [4] Low-Voltage Detection/Voltage Brown-Out Detector Disable LVD/VBO 0 = LVD/VBO Enabled. 1 = LVD/VBO Disabled. The LVD and VBO circuits are enabled or disabled separately to minimize power consumption in low-power modes. The LVD is controlled by the LVD/VBO bit only in all modes. The VBO is set by the LVD/VBO bit and the VBO_AO bit of Flash Option bit at Program Memory Address 0000h. Table 15 on page 45 lists the setup condition for LVD and VBO circuits in different operation modes. [3] TEMP Temperature Sensor Disable 0 = Temperature Sensor Enabled. 1 = Temperature Sensor Disabled. PS025016-1013 PRELIMINARY Low-Power Modes Z8 Encore! XP® F1680 Series Product Specification 45 Bit Description [2] Reserved; must be 0. [1] COMP0 Comparator 0 Disable 0 = Comparator 0 is Enabled (this applies even in STOP Mode). 1 = Comparator 0 is Disabled. [0] COMP1 Comparator 1 Disable 0 = Comparator 1 is Enabled (this applies even in STOP Mode). 1 = Comparator 1 is Disabled. Table 15. Setup Condition for LVD and VBO Circuits in Different Operation Modes LVD/VBO Bit Setup1 Operation Mode VBO_AO Bit Setup VBO_AO="1" or enabled2 VBO_AO="0" or disabled3 LVD/VBO Bit = "0" or enabled LVD/VBO Bit = "1" or disabled ACTIVE/HALT Mode STOP Mode ACTIVE/HALT Mode STOP Mode LVD "ON" LVD "OFF" VBO "ON" VBO "ON" LVD "ON" LVD "OFF" VBO "ON" VBO "OFF" VBO "OFF" VBO "OFF" Notes: 1. The LVD can be turned ON or OFF by the LVD/VBO bit in any mode. 2. When VBO_AO Bit is enabled, VBO is always ON for all modes no matter the setting of LVD/VBO Bit. 3. When VBO_AO Bit is disabled, VBO circuit is always OFF in STOP Mode no matter the setting of LVD/VBO Bit. And VBO can be turned On or OFF by the LVD/VBO Bit in ACTIVE and HALT modes. PS025016-1013 PRELIMINARY Low-Power Modes Z8 Encore! XP® F1680 Series Product Specification 46 Chapter 7. General-Purpose Input/Output The Z8 Encore! XP F1680 Series product supports a maximum of 37 port pins (Ports A– E) for general-purpose input/output (GPIO) operations. Each port contains control and data registers. The GPIO control registers determine data direction, open-drain, output drive current, programmable pull-ups, Stop Mode Recovery functionality and alternate pin functions. Each port pin is individually programmable. In addition, the Port C pins are capable of direct LED drive at programmable drive strengths. 7.1. GPIO Port Availability by Device Table 16 lists the port pins available with each device and package type. Table 16. Port Availability by Device and Package Type 10-bit ADC SPI 20-pin PDIP SOIC SSOP 7 0 [7:0] [3:0] [3:0] [0] — 17 28-pin PDIP SOIC SSOP 8 1 [7:0] [5:0] [7:0] [0] — 23 Z8F2480PM, Z8F1680PM, 40-pin Z8F0880PM PDIP 8 1 [7:0] [5:0] [7:0] [7:0] [2:0] 33 Z8F2480AN, Z8F2480QN; 44-pin Z8F1680AN, Z8F1680QN; LQFP Z8F0880AN, Z8F0880QN QFN 8 1 [7:0] [5:0] [7:0] [7:0] [6:0] 37 Devices Package Z8F2480PH, Z8F2480hH Z8F2480SH; Z8F1680PH, Z8F1680hH Z8F1680SH; Z8F0880PH, Z8F0880hH Z8F0880SH Z8F2480PJ, Z8F2480SJ Z8F2480hJ; Z8F1680PJ, Z8F1680SJ Z8F1680hJ; Z8F0880PJ, Z8F0880SJ Z8F0880hJ PS025016-1013 Port A Port B Port C Port D Port E PRELIMINARY Total I/O General-Purpose Input/Output Z8 Encore! XP® F1680 Series Product Specification 47 7.2. Architecture Figure 9 displays a simplified block diagram of a GPIO port pin and does not illustrate the ability to accommodate alternate functions and variable port current drive strength. Port Input Data Register Q D Schmitt-Trigger Q D System Clock VDD Port Output Control Port Output Data Register DATA Bus D Q Port Pin System Clock Port Data Direction GND Figure 9. GPIO Port Pin Block Diagram 7.3. GPIO Alternate Functions Many GPIO port pins are used for GPIO and to access the on-chip peripheral functions like the timers and serial-communication devices. The Port A–E Alternate Function subregisters configure these pins for either GPIO or alternate function operation. When a pin is configured for alternate function, control of port-pin direction (input/output) is passed from Port A–E Data Direction registers to the alternate functions assigned to this pin. Tables 17 through 19 list the alternate functions possible with each port pin for every package. The alternate function associated at a pin is defined through alternate function sets subregisters AFS1 and AFS2. The crystal oscillator and the 32 kHz secondary oscillator functionalities are not controlled by the GPIO block. When the crystal oscillator or the 32 kHz secondary oscillator is enabled in the oscillator control block, the GPIO functionality of PA0 and PA1, or PA2 and PA3, is overridden. In such a case, those pins function as input and output for the crystal oscillator. PS025016-1013 PRELIMINARY General-Purpose Input/Output Z8 Encore! XP® F1680 Series Product Specification 48 7.4. Direct LED Drive The Port C pins provide a current synchronized output capable of driving an LED without requiring an external resistor. The output synchronizes current at programmable levels of 3 mA, 7 mA, 13 mA and 20 mA. This mode is enabled through the Alternate Function subregister AFS1 and is programmable through the LED control registers. For proper function, the LED anode must be connected to VDD and the cathode to the GPIO pin. Using all Port C pins in LED drive mode with maximum current can result in excessive total current. For the maximum total current for the applicable package, see the Electrical Characteristics chapter on page 349. 7.5. Shared Reset Pin On all the devices, the Port D0 pin shares function with a bidirectional reset pin. Unlike all other I/O pins, this pin does not default to GPIO pin on power-up. This pin acts as a bidirectional input/open-drain output reset with an internal pull-up until user software reconfigures it as GPIO PD0. The Port D0 pin is output-only when in GPIO Mode, and must be configured as an output. PD0 supports the High Drive feature but not the Stop Mode Recovery feature. 7.6. Crystal Oscillator Override For systems using the crystal oscillator, PA0 and PA1 is used to connect the crystal. When the main crystal oscillator is enabled (see the Oscillator Control1 Register section on page 320), the GPIO settings are overridden and PA0 and PA1 is disabled. 7.7. 32 kHz Secondary Oscillator Override For systems using a 32 kHz secondary oscillator, PA2 and PA3 is used to connect a watch crystal. When the 32 kHz secondary oscillator is enabled (see the Oscillator Control1 Register section on page 320), the GPIO settings are overridden and PA2 and PA3 is disabled. 7.8. 5 V Tolerance All GPIO pins, including those that share functionality with an ADC, crystal or comparator signals are 5 V-tolerant and can handle inputs higher than VDD even with the pull-ups enabled. PS025016-1013 PRELIMINARY General-Purpose Input/Output Z8 Encore! XP® F1680 Series Product Specification 49 7.9. External Clock Setup For systems using an external TTL drive, PB3 is the clock source for 20-pin, 28-pin, 40pin and 44-pin devices. In this case, configure PB3 for alternate function CLKIN. Write to the Oscillator Control Register (see page 320) such that the external oscillator is selected as the system clock. Table 17. Port Alternate Function Mapping, 20-Pin Parts1,2 Port Pin Mnemonic Alternate Function Description Port A PA0 T0IN/T0OUT Timer 0 Input/Timer 0 Output Complement Reserved PA1 T0OUT DE0 Timer 0 Output CTS0 UART 0 Driver Enable PA5 PA6 PA7 AFS1[2]: 0 AFS1[2]: 1 UART 0 Clear to Send Reserved PA4 AFS1[1]: 0 AFS1[1]: 1 Reserved PA3 AFS1[0]: 0 AFS1[0]: 1 Reserved PA2 Alternate Function Set Register AFS1 AFS1[3]: 0 AFS1[3]: 1 RXD0/IRRX0 UART 0/IrDA 0 Receive Data AFS1[4]: 0 T2IN/T2OUT Timer 2 Input/Timer 2 Output Complement AFS1[4]: 1 TXD0/IRTX0 UART 0/IrDA 0 Transmit Data AFS1[5]: 0 T2OUT Timer 2 Output AFS1[5]: 1 T1IN/T1OUT Timer 1 Input/Timer 1 Output Complement AFS1[6]: 0 SCL I2C Serial Clock AFS1[6]: 1 T1OUT Timer 1 Output AFS1[7]: 0 SDA 2 I C Serial Data AFS1[7]: 1 Notes: 1. Because there are at most two choices of alternate functions for some pins in Port A, the Alternate Function Set Register (AFS2) is implemented but not used to select the function. The alternate function selection must also be enabled, as described in the Port A–E Alternate Function Subregisters section on page 61. 2. Because there is only one alternate function for each Port D pin, the Alternate Function Set registers are not implemented for Port D. Enabling the alternate function selections automatically enables the associated alternate function, as described in the Port A–E Alternate Function Subregisters section on page 61. PS025016-1013 PRELIMINARY General-Purpose Input/Output Z8 Encore! XP® F1680 Series Product Specification 50 Table 17. Port Alternate Function Mapping, 20-Pin Parts1,2 (Continued) Port Pin Mnemonic Port B PB0 Reserved ANA0/AMPOUT PB1 PB3 Port C PC0 PC3 Port D PD0 AFS1[0]: 1 AFS1[1]: 0 ADC Analog Input/LPO Input (N) AFS1[1]: 1 AFS1[2]: 0 ANA2/AMPINP ADC Analog Input/LPO Input (P) AFS1[2]: 1 CLKIN External Clock Input AFS1[3]: 0 ANA3 ADC Analog Input AFS1[3]: 1 Reserved AFS1[0]: 0 ADC or Comparator 0 Input (P), or LED drive Reserved ANA5/C0INN/LED PC2 ADC Analog Input/LPO Output Reserved ANA4/C0INP/LED PC1 AFS1[0]: 0 Reserved ANA1/AMPINN PB2 Alternate Function Set Register AFS1 Alternate Function Description AFS1[0]: 1 AFS1[1]: 0 ADC or Comparator 0 Input (N), or LED drive Reserved AFS1[1]: 1 AFS1[2]: 0 VREF/ANA6/LED Voltage Reference or ADC Analog Input or LED Drive AFS1[2]: 1 C0OUT Comparator 0 Output AFS1[3]: 0 LED LED drive AFS1[3]: 1 RESET External Reset N/A Notes: 1. Because there are at most two choices of alternate functions for some pins in Port A, the Alternate Function Set Register (AFS2) is implemented but not used to select the function. The alternate function selection must also be enabled, as described in the Port A–E Alternate Function Subregisters section on page 61. 2. Because there is only one alternate function for each Port D pin, the Alternate Function Set registers are not implemented for Port D. Enabling the alternate function selections automatically enables the associated alternate function, as described in the Port A–E Alternate Function Subregisters section on page 61. PS025016-1013 PRELIMINARY General-Purpose Input/Output Z8 Encore! XP® F1680 Series Product Specification 51 Table 18. Port Alternate Function Mapping, 28-Pin Parts1,2 Port Pin Mnemonic Alternate Function Description Alternate Function Set Register AFS1 Port A PA0 T0IN/T0OUT Timer 0 Input/Timer 0 Output Complement AFS1[0]: 0 Reserved PA1 T0OUT AFS1[0]: 1 Timer 0 Output AFS1[1]: 0 Reserved PA2 DE0 AFS1[1]: 1 UART 0 Driver Enable AFS1[2]: 0 Reserved PA3 CTS0 AFS1[2]: 1 UART 0 Clear to Send AFS1[3]: 0 Reserved PA4 RXD0/IRRX0 AFS1[3]: 1 UART 0/IrDA 0 Receive Data AFS1[4]: 0 Reserved PA5 TXD0/IRTX0 AFS1[4]: 1 UART 0/IrDA 0 Transmit Data AFS1[5]: 0 Reserved PA6 PA7 AFS1[5]: 1 T1IN/T1OUT Timer 1 Input/Timer 1 Output Complement AFS1[6]: 0 SCL I2C Serial Clock AFS1[6]: 1 T1OUT Timer 1 Output AFS1[7]: 0 SDA 2 I C Serial Data AFS1[7]: 1 Notes: 1. Because there are at most two choices of alternate functions for some pins in Ports A and B, the Alternate Function Set Register (AFS2) is implemented but not used to select the function. The alternate function selection must also be enabled, as described in the Port A–E Alternate Function Subregisters section on page 61. 2. Because there is only one alternate function for each Port D and Port E pin, the Alternate Function Set registers are not implemented for Ports D and E. Enabling the alternate function selections automatically enables the associated alternate function, as described in the Port A–E Alternate Function Subregisters section on page 61. PS025016-1013 PRELIMINARY General-Purpose Input/Output Z8 Encore! XP® F1680 Series Product Specification 52 Table 18. Port Alternate Function Mapping, 28-Pin Parts1,2 (Continued) Port Pin Mnemonic Port B PB0 Reserved ANA0/AMPOUT PB1 PB3 PB4 ADC Analog Input/LPO Output AFS1[0]: 1 AFS1[1]: 0 ADC Analog Input/LPO Input (N) Reserved AFS1[1]: 1 AFS1[2]: 0 ANA2/AMPINP ADC Analog Input/LPO Input (P) AFS1[2]: 1 CLKIN External Clock Input AFS1[3]: 0 ANA3 ADC Analog Input AFS1[3]: 1 Reserved ANA7 PB5 Alternate Function Set Register AFS1 AFS1[0]: 0 Reserved ANA1/AMPINN PB2 Alternate Function Description AFS1[4]: 0 ADC Analog Input Reserved VREF AFS1[4]: 1 AFS1[5]: 0 Voltage Reference AFS1[5]: 1 Notes: 1. Because there are at most two choices of alternate functions for some pins in Ports A and B, the Alternate Function Set Register (AFS2) is implemented but not used to select the function. The alternate function selection must also be enabled, as described in the Port A–E Alternate Function Subregisters section on page 61. 2. Because there is only one alternate function for each Port D and Port E pin, the Alternate Function Set registers are not implemented for Ports D and E. Enabling the alternate function selections automatically enables the associated alternate function, as described in the Port A–E Alternate Function Subregisters section on page 61. PS025016-1013 PRELIMINARY General-Purpose Input/Output Z8 Encore! XP® F1680 Series Product Specification 53 Table 18. Port Alternate Function Mapping, 28-Pin Parts1,2 (Continued) Alternate Function Set Register AFS1 Port Pin Mnemonic Port C PC0 Reserved AFS1[0]: 0 ANA4/C0INP/LED ADC or Comparator 0 Input (P), or LED drive AFS1[0]: 1 MISO AFS1[1]: 0 PC1 Alternate Function Description SPI Master In/Slave Out ANA5/C0INN/LED ADC or Comparator 0 Input (N), or LED Drive PC2 PC3 PC4 PC5 PC6 PC7 Port D PD0 AFS1[1]: 1 SS SPI Slave Select AFS1[2]: 0 ANA6/LED ADC Analog Input or LED Drive AFS1[2]: 1 C0OUT Comparator 0 Output AFS1[3]: 0 LED LED drive AFS1[3]: 1 MOSI SPI Master Out/Slave In AFS1[4]: 0 LED LED Drive AFS1[4]: 1 SCK SPI Serial Clock AFS1[5]: 0 LED LED Drive AFS1[5]: 1 T2IN/T2OUT Timer 2 Input/Timer 2 Output Complement AFS1[6]: 0 LED LED Drive AFS1[6]: 1 T2OUT Timer 2 Output AFS1[7]: 0 LED LED Drive AFS1[7]: 1 RESET External Reset N/A Notes: 1. Because there are at most two choices of alternate functions for some pins in Ports A and B, the Alternate Function Set Register (AFS2) is implemented but not used to select the function. The alternate function selection must also be enabled, as described in the Port A–E Alternate Function Subregisters section on page 61. 2. Because there is only one alternate function for each Port D and Port E pin, the Alternate Function Set registers are not implemented for Ports D and E. Enabling the alternate function selections automatically enables the associated alternate function, as described in the Port A–E Alternate Function Subregisters section on page 61. PS025016-1013 PRELIMINARY General-Purpose Input/Output Z8 Encore! XP® F1680 Series Product Specification 54 Table 19. Port Alternate Function Mapping, 40-/44-Pin Parts1,2 Port Pin Mnemonic Alternate Function Description Alternate Function Set Register AFS1 Port A PA0 T0IN/T0OUT Timer 0 Input/Timer 0 Output Complement AFS1[0]: 0 Reserved PA1 T0OUT AFS1[0]: 1 Timer 0 Output AFS1[1]: 0 Reserved PA2 DE0 AFS1[1]: 1 UART 0 Driver Enable AFS1[2]: 0 Reserved PA3 CTS0 AFS1[2]: 1 UART 0 Clear to Send AFS1[3]: 0 Reserved PA4 RXD0/IRRX0 AFS1[3]: 1 UART 0/IrDA 0 Receive Data AFS1[4]: 0 AFS1[4]: 1 PA5 TXD0/IRTX0 UART 0/IrDA 0 Transmit Data AFS1[5]: 0 AFS1[5]: 1 PA6 T1IN/T1OUT Timer 1 Input/Timer 1 Output Complement Reserved PA7 T1OUT AFS1[6]: 0 AFS1[6]: 1 Timer 1 Output Reserved AFS1[7]: 0 AFS1[7]: 1 Notes: 1. Because there are at most two choices of alternate functions for some pins in Ports A–C, the Alternate Function Set Register (AFS2) is implemented but not used to select the function. The alternate function selection must also be enabled, as described in the Port A–E Alternate Function Subregisters section on page 61. 2. Because there is only one alternate function for each Port D and Port E pin, the Alternate Function Set registers are not implemented for Ports D and E. Enabling the alternate function selections automatically enables the associated alternate function, as described in the Port A–E Alternate Function Subregisters section on page 61. 3. This timer function is only available in the 44-pin package; its alternate functions are reserved in the 40-pin package. PS025016-1013 PRELIMINARY General-Purpose Input/Output Z8 Encore! XP® F1680 Series Product Specification 55 Table 19. Port Alternate Function Mapping, 40-/44-Pin Parts1,2 (Continued) Port Pin Mnemonic Port B PB0 Reserved ANA0/AMPOUT PB1 PB3 PB4 ADC Analog Input/LPO Output AFS1[0]: 1 AFS1[1]: 0 ADC Analog Input/LPO Input (N) Reserved AFS1[1]: 1 AFS1[2]: 0 ANA2/AMPINP ADC Analog Input/LPO Input (P) AFS1[2]: 1 CLKIN External Clock Input AFS1[3]: 0 ANA3 ADC Analog Input AFS1[3]: 1 Reserved ANA7 PB5 AFS1[0]: 0 Reserved ANA1/AMPINN PB2 Alternate Function Description Alternate Function Set Register AFS1 AFS1[4]: 0 ADC Analog Input Reserved VREF AFS1[4]: 1 AFS1[5]: 0 Voltage Reference AFS1[5]: 1 Notes: 1. Because there are at most two choices of alternate functions for some pins in Ports A–C, the Alternate Function Set Register (AFS2) is implemented but not used to select the function. The alternate function selection must also be enabled, as described in the Port A–E Alternate Function Subregisters section on page 61. 2. Because there is only one alternate function for each Port D and Port E pin, the Alternate Function Set registers are not implemented for Ports D and E. Enabling the alternate function selections automatically enables the associated alternate function, as described in the Port A–E Alternate Function Subregisters section on page 61. 3. This timer function is only available in the 44-pin package; its alternate functions are reserved in the 40-pin package. PS025016-1013 PRELIMINARY General-Purpose Input/Output Z8 Encore! XP® F1680 Series Product Specification 56 Table 19. Port Alternate Function Mapping, 40-/44-Pin Parts1,2 (Continued) Port Pin Mnemonic Port C PC0 Reserved ANA4/C0INP/LED PC1 PC2 PC3 PC4 PC5 PC6 PC7 Alternate Function Set Register AFS1 Alternate Function Description AFS1[0]: 0 ADC or Comparator 0 Input (P), or LED drive Reserved AFS1[0]: 1 AFS1[1]: 0 ANA5/C0INN/LED ADC or Comparator 0 Input (N), or LED Drive AFS1[1]: 1 SS SPI Slave Select AFS1[2]: 0 ANA6/LED ADC Analog Input or LED Drive AFS1[2]: 1 MISO SPI Master In Slave Out AFS1[3]: 0 LED LED drive AFS1[3]: 1 MOSI SPI Master Out Slave In AFS1[4]: 0 LED LED Drive AFS1[4]: 1 SCK SPI Serial Clock AFS1[5]: 0 LED LED Drive AFS1[5]: 1 T2IN/T2OUT Timer 2 Input/Timer2 Output Complement AFS1[6]: 0 LED LED Drive AFS1[6]: 1 T2OUT Timer 2 Output AFS1[7]: 0 LED LED Drive AFS1[7]: 1 Notes: 1. Because there are at most two choices of alternate functions for some pins in Ports A–C, the Alternate Function Set Register (AFS2) is implemented but not used to select the function. The alternate function selection must also be enabled, as described in the Port A–E Alternate Function Subregisters section on page 61. 2. Because there is only one alternate function for each Port D and Port E pin, the Alternate Function Set registers are not implemented for Ports D and E. Enabling the alternate function selections automatically enables the associated alternate function, as described in the Port A–E Alternate Function Subregisters section on page 61. 3. This timer function is only available in the 44-pin package; its alternate functions are reserved in the 40-pin package. PS025016-1013 PRELIMINARY General-Purpose Input/Output Z8 Encore! XP® F1680 Series Product Specification 57 Table 19. Port Alternate Function Mapping, 40-/44-Pin Parts1,2 (Continued) Port Pin Mnemonic Alternate Function Description Alternate Function Set Register AFS1 Port D PD0 RESET External Reset N/A PD1 C1INN Comparator 1 Input (N) PD2 C1INP Comparator 1 Input (P) PD3 CTS1/C1OUT UART 1 Clear to Send or Comparator 1 Output PD4 RXD1/IRRX1 UART 1/IrDA 1 Receive Data PD5 TXD1/IRTX1 UART 1/IrDA 1 Transmit Data PD6 DE1 UART 1 Driver Enable PD7 C0OUT Comparator 0 Output PE0 T4IN3 Port E N/A Reserved PE1 SCL I2C Serial Clock Reserved PE2 SDA I2C Serial Data Reserved PE3 T4CHA3 Reserved PE4 T4CHB3 Reserved PE5 T4CHC3 Reserved PE6 T4CHD3 Reserved Notes: 1. Because there are at most two choices of alternate functions for some pins in Ports A–C, the Alternate Function Set Register (AFS2) is implemented but not used to select the function. The alternate function selection must also be enabled, as described in the Port A–E Alternate Function Subregisters section on page 61. 2. Because there is only one alternate function for each Port D and Port E pin, the Alternate Function Set registers are not implemented for Ports D and E. Enabling the alternate function selections automatically enables the associated alternate function, as described in the Port A–E Alternate Function Subregisters section on page 61. 3. This timer function is only available in the 44-pin package; its alternate functions are reserved in the 40-pin package. PS025016-1013 PRELIMINARY General-Purpose Input/Output Z8 Encore! XP® F1680 Series Product Specification 58 7.10. GPIO Interrupts Many of the GPIO port pins can be used as interrupt sources. Some port pins can be configured to generate an interrupt request on either the rising edge or falling edge of the pininput signal. Other port-pin interrupt sources generate an interrupt when any edge occurs (both rising and falling). For more details about interrupts using the GPIO pins, see the Interrupt Controller chapter on page 68. 7.11. GPIO Control Register Definitions Four registers for each port provide access to GPIO control, input data and output data. Table 20 lists these port registers. Use Port A–E Address and Control registers together to provide access to subregisters for port configuration and control. Table 20. GPIO Port Registers and Subregisters Port Register Mnemonic Port Register Name PxADDR Port A–E Address Register (Selects subregisters) PxCTL Port A–E Control Register (Provides access to subregisters) PxIN Port A–E Input Data Register PxOUT Port A–E Output Data Register Port Subregister Mnemonic Port Register Name PxDD Data Direction PxAF Alternate Function PxOC Output Control (Open-Drain) PxHDE High Drive Enable PxSMRE Stop Mode Recovery Source Enable PxPUE Pull-up Enable PxAFS1 Alternate Function Set 1 PxAFS2 Alternate Function Set 2 PS025016-1013 PRELIMINARY General-Purpose Input/Output Z8 Encore! XP® F1680 Series Product Specification 59 7.11.1. Port A–E Address Registers The Port A–E address registers select the GPIO Port functionality accessible through the Port A–E Control registers. The Port A–E Address and Control registers combine to provide access to all GPIO Port controls, see Table 21. Table 21. Port A–E GPIO Address Registers (PxADDR) Bits 7 6 5 4 3 Field PADDR[7:0] Reset 00h R/W R/W R/W R/W Address R/W R/W 2 1 0 R/W R/W R/W FD0h, FD4h, FD8h, FDCh, FE0h Bit Description [7:0] PADDR Port Address The Port Address selects one of the subregisters accessible through the Port Control Register. PADDR[7:0] Port Control Subregister Accessible using the Port A–E Control Registers 00h No function. Provides some protection against accidental port reconfiguration. 01h Data Direction. 02h Alternate Function. 03h Output Control (Open-Drain). 04h High Drive Enable. 05h Stop Mode Recovery Source Enable. 06h Pull-up Enable. 07h Alternate Function Set 1. 08h Alternate Function Set 2. 09h–FFh No function. PS025016-1013 PRELIMINARY General-Purpose Input/Output Z8 Encore! XP® F1680 Series Product Specification 60 7.11.2. Port A–E Control Registers The Port A–E Control registers set the GPIO port operation. The value in the corresponding Port A–E Address register determines which subregister is read from or written to by a Port A–E Control Register transaction, see Table 22. Table 22. Port A–E Control Registers (PxCTL) Bits 7 6 5 4 Field PCTL Reset 00h R/W R/W R/W R/W Address R/W 3 2 1 0 R/W R/W R/W R/W FD1h, FD5h, FD9h, FDDh, FE1h Bit Description [7:0] PCTL Port Control The Port Control Register provides access to all subregisters that configure the GPIO Port operation. 7.11.3. Port A–E Data Direction Subregisters The Port A–E Data Direction subregister is accessed through the Port A–E Control Register by writing 01h to the Port A–E Address register, as indicated in Table 23. Table 23. Port A–E Data Direction Subregisters (PxDD) Bits 7 6 5 4 3 2 1 0 Field DD7 DD6 DD5 DD4 DD3 DD2 DD1 DD0 Reset 1 1 1 1 1 1 1 1 R/W R/W R/W R/W R/W R/W R/W R/W R/W Address If 01h in Port A–E Address Register, accessible through the Port A–E Control Register. Bit Description [7:0] DD Data Direction These bits control the direction of the associated port pin. Port Alternate Function operation overrides the Data Direction register setting. 0 = Output. Data in the Port A–E Output Data Register is driven onto the port pin. 1 = Input. The port pin is sampled and the value written into the Port A–E Input Data Register. The output driver is tristated. PS025016-1013 PRELIMINARY General-Purpose Input/Output Z8 Encore! XP® F1680 Series Product Specification 61 7.11.4. Port A–E Alternate Function Subregisters The Port A–E Alternate Function Subregister, shown in Table 24, is accessed through the Port A–E Control Register by writing 02h to the Port A–E Address Register. The Port A– E Alternate Function subregisters enable the alternate function selection on the pins; if disabled, the pins function as GPIO. If enabled, select one of the four alternate functions using Alternate Function Set Subregisters 1 and 2 as described in the Port A–E Alternate Function Set 1 Subregisters section on page 64 and the Port A–E Alternate Function Set 2 Subregisters section on page 64. To determine the alternate function associated with each port pin, see the GPIO Alternate Functions section on page 47. Caution: Do not enable alternate functions for GPIO port pins for which there is no associated alternate function. Failure to follow this guideline results in unpredictable operation. Table 24. Port A–E Alternate Function Subregisters (PxAF) Bits 7 6 5 4 3 2 1 0 Field AF7 AF6 AF5 AF4 AF3 AF2 AF1 AF0 Reset 00h (Ports A–C); 01h (Port D); 00h (Port E); R/W R/W Address If 02h in Port A–D Address Register, accessible through the Port A–E Control Register. Bit Description [7:0] AF Port Alternate Function enabled 0 = The port pin is in NORMAL Mode and the DDx bit in the Port A–E Data Direction subregister determines the direction of the pin. 1 = The alternate function selected through Alternate Function set subregisters are enabled. Port-pin operation is controlled by the alternate function. PS025016-1013 PRELIMINARY General-Purpose Input/Output Z8 Encore! XP® F1680 Series Product Specification 62 7.11.5. Port A–E Output Control Subregisters The Port A–E Output Control Subregister, shown in Table 25, is accessed through the Port A–E Control Register by writing 03h to the Port A–E Address Register. Setting the bits in the Port A–E Output Control subregisters to 1 configures the specified port pins for opendrain operation. These subregisters affect the pins directly and, as a result, alternate functions are also affected. Table 25. Port A–E Output Control Subregisters (PxOC) Bits 7 6 5 4 3 2 1 0 Field POC7 POC6 POC5 POC4 POC3 POC2 POC1 POC0 Reset 0 0 0 0 0 0 0 0 R/W R/W R/W R/W R/W R/W R/W R/W R/W Address Bit [7:0] POC If 03h in Port A–E Address Register, accessible through the Port A–E Control Register Description Port Output Control These bits function independently of the alternate function bit and always disable the drains if set to 1. 0 = The drains are enabled for any output mode (unless overridden by the alternate function). 1 = The drain of the associated pin is disabled (open-drain mode). 7.11.6. Port A–E High Drive Enable Subregisters The Port A–E High Drive Enable Subregister, shown in Table 26, is accessed through the Port A–E Control Register by writing 04h to the Port A–E Address Register. Setting the bits in the Port A–E High Drive Enable subregisters to 1 configures the specified port pins for high-current output drive operation. The Port A–E High Drive Enable Subregister affects the pins directly and, as a result, alternate functions are also affected. Table 26. Port A–E High Drive Enable Subregisters (PxHDE) Bits 7 6 5 4 3 2 1 0 Field PHDE7 PHDE6 PHDE5 PHDE4 PHDE3 PHDE2 PHDE1 PHDE0 Reset 0 0 0 0 0 0 0 0 R/W R/W R/W R/W R/W R/W R/W R/W R/W Address Bit [7:0] PHDE If 04h in Port A–E Address Register, accessible through the Port A–E Control Register Description Port High Drive Enabled 0 = The Port pin is configured for standard output current drive. 1 = The Port pin is configured for high output current drive. PS025016-1013 PRELIMINARY General-Purpose Input/Output Z8 Encore! XP® F1680 Series Product Specification 63 7.11.7. Port A–E Stop Mode Recovery Source Enable Subregisters The Port A–E Stop Mode Recovery Source Enable Subregister, shown in Table 27, is accessed through the Port A–E Control Register by writing 05h to the Port A–E Address Register. Setting the bits in the Port A–E Stop Mode Recovery Source Enable subregisters to 1 configures the specified port pins as Stop Mode Recovery sources. During STOP Mode, any logic transition on a port pin enabled as a Stop Mode Recovery source initiates Stop Mode Recovery. Table 27. Port A–E Stop Mode Recovery Source Enable Subregisters (PxSMRE) Bits 7 6 5 4 3 2 1 0 Field PSMRE7 PSMRE6 PSMRE5 PSMRE4 PSMRE3 PSMRE2 PSMRE1 PSMRE0 Reset 0 0 0 0 0 0 0 0 R/W R/W R/W R/W R/W R/W R/W R/W R/W Address If 05h in Port A–E Address Register, accessible through the Port A–E Control Register. Bit [7:0] PSMRE Description Port Stop Mode Recovery Source Enabled 0 = The Port pin is not configured as a Stop Mode Recovery source. Transitions on this pin during STOP Mode do not initiate Stop Mode Recovery. 1 = The Port pin is configured as a Stop Mode Recovery source. Any logic transition on this pin during STOP Mode initiates Stop Mode Recovery. 7.11.8. Port A–E Pull-up Enable Subregisters The Port A–E Pull-up Enable Subregister, shown in Table 28, is accessed through the Port A–E Control Register by writing 06h to the Port A–E Address Register. Setting the bits in the Port A–E Pull-up Enable subregisters enables a weak internal resistive pull-up on the specified port pins. Table 28. Port A–E Pull-Up Enable Subregisters (PxPUE) Bits 7 6 5 4 3 2 1 0 Field PPUE7 PPUE6 PPUE5 PPUE4 PPUE3 PPUE2 PPUE1 PPUE0 Reset 0 0 0 0 0 0 0 0 R/W R/W R/W R/W R/W R/W R/W R/W R/W Address If 06h in Port A–E Address Register, accessible through the Port A–E Control Register. Bit [7:0] PPUE Description Port Pull-up Enabled 0 = The weak pull-up on the Port pin is disabled. 1 = The weak pull-up on the Port pin is enabled. PS025016-1013 PRELIMINARY General-Purpose Input/Output Z8 Encore! XP® F1680 Series Product Specification 64 7.11.9. Port A–E Alternate Function Set 1 Subregisters The Port A–E Alternate Function Set1 Subregister, shown in Table 29, is accessed through the Port A–E Control Register by writing 07h to the Port A–E Address Register. The Alternate Function Set 1 subregisters select the alternate function available at a port pin. Alternate Functions selected by setting or clearing bits of this register are defined in the GPIO Alternate Functions section on page 47. Alternate function selection on the port pins must also be enabled as described in the Port A–E Alternate Function Subregisters section on page 61. Note: Table 29. Port A–E Alternate Function Set 1 Subregisters (PxAFS1) Bits 7 6 5 4 3 2 1 0 Field PAFS17 PAFS16 PAFS15 PAFS14 PAFS13 PAFS12 PAFS11 PAFS10 Reset 0 0 0 0 0 0 0 0 R/W R/W R/W R/W R/W R/W R/W R/W R/W Address If 07h in Port A–E Address Register, accessible through the Port A–E Control Register Bit Description [7:0] PAFS1 Port Alternate Function Set 1 0 = Port Alternate Function selected, as defined in the GPIO Alternate Functions section on page 47. 1 = Port Alternate Function selected, as defined in the GPIO Alternate Functions section on page 47. 7.11.10. Port A–E Alternate Function Set 2 Subregisters The Port A–E Alternate Function Set 2 Subregister, shown in Table 30, is accessed through the Port A–E Control Register by writing 08h to the Port A–E Address Register. The Alternate Function Set 2 subregisters select the alternate function available at a port pin. Alternate Functions selected by setting or clearing bits of this register are defined in the GPIO Alternate Functions section on page 47. Note: PS025016-1013 Alternate function selection on port pins must also be enabled as described in the Port A– E Alternate Function Subregisters section on page 61. PRELIMINARY General-Purpose Input/Output Z8 Encore! XP® F1680 Series Product Specification 65 Table 30. Port A–E Alternate Function Set 2 Subregisters (PxAFS2) Bits 7 6 5 4 3 2 1 0 Field PAFS27 PAFS26 PAFS25 PAFS24 PAFS23 PAFS22 PAFS21 PAFS20 Reset 0 0 0 0 0 0 0 0 R/W R/W R/W R/W R/W R/W R/W R/W R/W Address If 08h in Port A–E Address Register, accessible through the Port A–E Control Register Bit Description [7:0] PAFS2 Port Alternate Function Set 2 0 = Port Alternate Function selected as defined in the GPIO Alternate Functions section on page 47. 1 = Port Alternate Function selected as defined the GPIO Alternate Functions section on page 47. 7.11.11. Port A–E Input Data Registers Reading from the Port A–E Input Data registers, shown in Table 31, returns the sampled values from the corresponding port pins. The Port A–E Input Data registers are read-only. The value returned for any unused ports is 0. Unused ports include those missing on the 8pin and 28-pin packages, as well as those missing on the ADC-enabled 28-pin packages. Table 31. Port A–E Input Data Registers (PxIN) Bits 7 6 5 4 3 2 1 0 Field PIN7 PIN6 PIN5 PIN4 PIN3 PIN2 PIN1 PIN0 Reset X X X X X X X X R/W R R R R R R R R Address FD2h, FD6h, FDAh, FDEh, FE2h Bit Description [7:0] PIN Port Input Data Sampled data from the corresponding port pin input. 0 = Input data is logical 0 (Low). 1 = Input data is logical 1 (High). PS025016-1013 PRELIMINARY General-Purpose Input/Output Z8 Encore! XP® F1680 Series Product Specification 66 7.11.12. Port A–E Output Data Register The Port A–E Output Data Register, shown in Table 32, controls the output data to the pins. Table 32. Port A–E Output Data Register (PxOUT) Bits 7 6 5 4 3 2 1 0 Field POUT7 POUT6 POUT5 POUT4 POUT3 POUT2 POUT1 POUT0 Reset 0 0 0 0 0 0 0 0 R/W R/W R/W R/W R/W R/W R/W R/W R/W Address FD3h, FD7h, FDBh, FDFh, FE3h Bit Description [7:0] POUT Port Output Data These bits contain the data to be driven to the port pins. The values are only driven if the corresponding pin is configured as an output and the pin is not configured for Alternate Function operation. 0 = Drive a logical 0 (Low). 1 = Drive a logical 1 (High). High value is not driven if the drain has been disabled by setting the corresponding Port Output Control Register bit to 1. 7.11.13. LED Drive Enable Register The LED Drive Enable Register, shown in Table 33, activates the controlled current drive. The Port C pin must first be enabled by setting the Alternate Function Register to select the LED function. Table 33. LED Drive Enable (LEDEN) Bits 7 6 5 Field 3 2 1 0 LEDEN[7:0] Reset R/W 4 0 0 0 0 0 0 0 0 R/W R/W R/W R/W R/W R/W R/W R/W Address F82h Bit Description [7:0] LEDEN LED Drive Enable These bits determine which Port C pins are connected to an internal current sink. 0 = Tristate the Port C pin. 1 = Connect controlled current synch to Port C pin. PS025016-1013 PRELIMINARY General-Purpose Input/Output Z8 Encore! XP® F1680 Series Product Specification 67 7.11.14. LED Drive Level Registers Two LED Drive Level registers consist of the LED Drive Level High Bit Register (LEDLVLH[7:0]) and the LED Drive Level Low Bit Register (LEDLVLL[7:0]), as shown in Tables 34 and 35. Two control bits, LEDLVLH[x] and LEDLVLL[x], are used to select one of four programmable current drive levels for each associated Port C[x] pin. Each Port C pin is individually programmable. Table 34. LED Drive Level High Bit Register (LEDLVLH) Bits 7 6 5 4 Field 2 1 0 LEDLVLH Reset R/W 3 0 0 0 0 0 0 0 0 R/W R/W R/W R/W R/W R/W R/W R/W Address F83h Table 35. LED Drive Level Low Bit Register (LEDLVLL) Bits 7 6 5 4 Field 2 1 0 LEDLVLL Reset R/W 3 0 0 0 0 0 0 0 0 R/W R/W R/W R/W R/W R/W R/W R/W Address F84h Bit Description [7:0] LEDLVLH, LEDLVLL LED Drive Level High Bit LED Drive Level Low Bit These bits are used to set the LED drive current. {LEDLVLH[x], LEDLVLL[x]}, in which x=Port C[0] to Port C[7]. Select one of the following four programmable current drive levels for each Port C pin. 00 = 3 mA 01 = 7 mA 10 = 13 mA 11 = 20 mA PS025016-1013 PRELIMINARY General-Purpose Input/Output Z8 Encore! XP® F1680 Series Product Specification 68 Chapter 8. Interrupt Controller The interrupt controller on the Z8 Encore! XP F1680 Series products prioritizes the interrupt requests from the on-chip peripherals and the GPIO port pins. The interrupt controller includes the following features: • Thirty-one interrupt sources using twenty-four unique interrupt vectors – 16 GPIO port pin interrupt sources (seven interrupt vectors are shared; see Table 36) – 15 on-chip peripheral interrupt sources (three interrupt vectors are shared; see Table 36) • Flexible GPIO interrupts – Twelve selectable rising and falling edge GPIO interrupts – Four dual-edge interrupts • • Three levels of individually programmable interrupt priority WDT can be configured to generate an interrupt Interrupt requests (IRQs) allow peripheral devices to suspend CPU operation in an orderly manner and force the CPU to start an interrupt service routine (ISR). Usually this interrupt service routine is involved with the exchange of data, status information, or control information between the CPU and the interrupting peripheral. When the service routine is completed, the CPU returns to the operation from which it was interrupted. The eZ8 CPU supports both vectored and polled interrupt handling. For polled interrupts, the interrupt controller has no effect on operation. For more information about interrupt servicing by the eZ8 CPU, refer to the eZ8 CPU Core User Manual (UM0128), available on www.zilog.com. 8.1. Interrupt Vector Listing Table 36 lists all of the interrupts available in order of priority. The interrupt vector is stored with the most-significant byte (MSB) at the even Program Memory address and the least-significant byte (LSB) at the following odd Program Memory address. Note: PS025016-1013 Some port interrupts are not available on the 20-pin and 28-pin packages. The ADC interrupt is unavailable on devices not containing an ADC. PRELIMINARY Interrupt Controller Z8 Encore! XP® F1680 Series Product Specification 69 Table 36. Trap and Interrupt Vectors in Order of Priority Program Memory Priority* Vector Address Interrupt or Trap Source Highest 0002h Reset (not an interrupt) 0004h Watchdog Timer (see the Watchdog Timer chapter on page 140) 003Ah Primary Oscillator Fail Trap (not an interrupt) 003Ch Watchdog Timer Oscillator Fail Trap (not an interrupt) 0006h Illegal Instruction Trap (not an interrupt) 0008h Timer 2 000Ah Timer 1 000Ch Timer 0 000Eh UART 0 receiver 0010h UART 0 transmitter 0012h I 2C 0014h SPI 0016h ADC 0018h Port A7, selectable rising or falling input edge or LVD (see the Reset, Stop Mode Recovery and Low-Voltage Detection chapter on page 31) 001Ah Port A6, selectable rising or falling input edge or Comparator 0 Output 001Ch Port A5, selectable rising or falling input edge or Comparator 1 Output 001Eh Port A4 or Port D4, selectable rising or falling input edge 0020h Port A3 or Port D3, selectable rising or falling input edge 0022h Port A2 or Port D2, selectable rising or falling input edge 0024h Port A1 or Port D1, selectable rising or falling input edge 0026h Port A0, selectable rising or falling input edge 0028h Reserved 002Ah Multi-channel Timer 002Ch UART 1 receiver 002Eh UART 1 transmitter 0030h Port C3, both input edges 0032h Port C2, both input edges 0034h Port C1, both input edges 0036h Port C0, both input edges 0038h Reserved Lowest Note: *The order of priority is only meaningful when considering identical interrupt levels. This priority varies depending on different interrupt level settings. See the Interrupt Vectors and Priority section on page 71 for details. PS025016-1013 PRELIMINARY Interrupt Controller Z8 Encore! XP® F1680 Series Product Specification 70 8.2. Architecture Figure 10 displays the interrupt controller block diagram. High Priority Internal Interrupts Interrupt Request Latches and Control Port Interrupts Vector Medium Priority Priority Mux IRQ Request Low Priority Figure 10. Interrupt Controller Block Diagram 8.3. Operation This section describes the operational aspects of the following functions. Master Interrupt Enable: see page 70 Interrupt Vectors and Priority: see page 71 Interrupt Assertion: see page 71 Software Interrupt Assertion: see page 72 8.3.1. Master Interrupt Enable The master interrupt enable bit (IRQE) in the Interrupt Control Register globally enables and disables interrupts. Interrupts are globally enabled by any of the following actions: • • PS025016-1013 Execution of an Enable Interrupt (EI) instruction Execution of an Interrupt Return (IRET) instruction PRELIMINARY Interrupt Controller Z8 Encore! XP® F1680 Series Product Specification 71 • Writing 1 to the IRQE bit in the interrupt control register Interrupts are globally disabled by any of the following actions: • • • • • • • • Execution of a Disable Interrupt (DI) instruction eZ8 CPU acknowledgement of an interrupt service request from the interrupt controller Writing 0 to the IRQE bit in the interrupt control register Reset Execution of a Trap instruction Illegal Instruction Trap Primary Oscillator Fail Trap Watchdog Oscillator Fail Trap 8.3.2. Interrupt Vectors and Priority The interrupt controller supports three levels of interrupt priority. Level 3 is the highest priority, Level 2 is the second highest priority and Level 1 is the lowest priority. If all the interrupts are enabled with identical interrupt priority (for example, all as Level 2 interrupts), the interrupt priority is assigned from highest to lowest as specified in Table 36 on page 69. Level 3 interrupts are always assigned higher priority than Level 2 interrupts which, in turn, always are assigned higher priority than Level 1 interrupts. Within each interrupt priority level (Level 1, Level 2, or Level 3), priority is assigned as specified in Table 36. Reset, Watchdog Timer interrupt (if enabled), Primary Oscillator Fail Trap, Watchdog Timer Oscillator Fail Trap and Illegal Instruction Trap always have highest (Level 3) priority. 8.3.3. Interrupt Assertion Interrupt sources assert their interrupt requests for only a single-system clock period (single-pulse). When the interrupt request is acknowledged by the eZ8 CPU, the corresponding bit in the Interrupt Request Register is cleared until the next interrupt occurs. Writing a 0 to the corresponding bit in the Interrupt Request Register likewise clears the interrupt request. Caution: Zilog recommends not using a coding style that clears bits in the Interrupt Request registers. All incoming interrupts received between execution of the first LDX command and the final LDX command are lost. See Example 1, which follows. PS025016-1013 PRELIMINARY Interrupt Controller Z8 Encore! XP® F1680 Series Product Specification 72 Example 1. A poor coding style that can result in lost interrupt requests: LDX r0, IRQ0 AND r0, MASK LDX IRQ0, r0 To avoid missing interrupts, use the coding style in Example 2 to clear bits in the Interrupt Request 0 Register: Example 2. A good coding style that avoids lost interrupt requests: ANDX IRQ0, MASK 8.3.4. Software Interrupt Assertion Program code can generate interrupts directly. Writing a 1 to the correct bit in the Interrupt Request Register triggers an interrupt (assuming that the interrupt is enabled). When the interrupt request is acknowledged by the eZ8 CPU, the bit in the Interrupt Request Register is automatically cleared to 0. Caution: Zilog recommends not using a coding style to generate software interrupts by setting bits in the Interrupt Request registers. All incoming interrupts received between execution of the first LDX command and the final LDX command are lost. See Example 3, which follows. Example 3. A poor coding style that can result in lost interrupt requests: LDX r0, IRQ0 OR r0, MASK LDX IRQ0, r0 To avoid missing interrupts, use the coding style in Example 4 to set bits in the Interrupt Request registers: Example 4. A good coding style that avoids lost interrupt requests: ORX IRQ0, MASK 8.4. Interrupt Control Register Definitions For all interrupts other than the Watchdog Timer interrupt, the Primary Oscillator Fail Trap and the Watchdog Oscillator Fail Trap, the Interrupt Control registers enable individual interrupts, set interrupt priorities and indicate interrupt requests. PS025016-1013 PRELIMINARY Interrupt Controller Z8 Encore! XP® F1680 Series Product Specification 73 8.4.1. Interrupt Request 0 Register The Interrupt Request 0 (IRQ0) Register, shown in Table 37, stores the interrupt requests for both vectored and polled interrupts. When a request is presented to the interrupt controller, the corresponding bit in the IRQ0 register becomes 1. If interrupts are globally enabled (vectored interrupts), the interrupt controller passes an interrupt request to the eZ8 CPU. If interrupts are globally disabled (polled interrupts), the eZ8 CPU can read the Interrupt Request 0 register to determine if any interrupt requests are pending. Table 37. Interrupt Request 0 Register (IRQ0) Bits 7 6 5 4 3 2 1 0 Field T2I T1I T0I U0RXI U0TXI I2CI SPII ADCI Reset 0 0 0 0 0 0 0 0 R/W R/W R/W R/W R/W R/W R/W R/W R/W Address FC0h Bit Description [7] T2I Timer 2 Interrupt Request 0 = No interrupt request is pending for Timer 2. 1 = An interrupt request from Timer 2 is awaiting service. [6] T1I Timer 1 Interrupt Request 0 = No interrupt request is pending for Timer 1. 1 = An interrupt request from Timer 1 is awaiting service. [5] T0I Timer 0 Interrupt Request 0 = No interrupt request is pending for Timer 0. 1 = An interrupt request from Timer 0 is awaiting service. [4] U0RXI UART 0 Receiver Interrupt Request 0 = No interrupt request is pending for the UART 0 receiver. 1 = An interrupt request from the UART 0 receiver is awaiting service. [3] U0TXI UART 0 Transmitter Interrupt Request 0 = No interrupt request is pending for the UART 0 transmitter. 1 = An interrupt request from the UART 0 transmitter is awaiting service. [2] I2CI I2C Interrupt Request 0 = No interrupt request is pending for the I2C. 1 = An interrupt request from I2C is awaiting service. [1] SPII SPI Interrupt Request 0 = No interrupt request is pending for the SPI. 1 = An interrupt request from the SPI is awaiting service. [0] ADCI ADC Interrupt Request 0 = No interrupt request is pending for the ADC. 1 = An interrupt request from the ADC is awaiting service. PS025016-1013 PRELIMINARY Interrupt Controller Z8 Encore! XP® F1680 Series Product Specification 74 8.4.2. Interrupt Request 1 Register The Interrupt Request 1 (IRQ1) Register, shown in Table 38, stores interrupt requests for both vectored and polled interrupts. When a request is presented to the interrupt controller, the corresponding bit in the IRQ1 register becomes a 1. If interrupts are globally enabled (vectored interrupts), the interrupt controller passes an interrupt request to the eZ8 CPU. If interrupts are globally disabled (polled interrupts), the eZ8 CPU can read the Interrupt Request 1 register to determine if any interrupt requests are pending. Table 38. Interrupt Request 1 Register (IRQ1) Bits 7 6 5 4 3 2 1 0 Field PA7VI PA6CI PA5CI PAD4I PAD3I PAD2I PAD1I PA0I Reset 0 0 0 0 0 0 0 0 R/W R/W R/W R/W R/W R/W R/W R/W R/W Address FC3h Bit Description [7] PA7VI Port A7 or LVD Interrupt Request 0 = No interrupt request is pending for GPIO Port A7 or LVD. 1 = An interrupt request from GPIO Port A7 or LVD. [6] PA6CI Port A6 or Comparator 0 Interrupt Request 0 = No interrupt request is pending for GPIO Port A6 or Comparator 0. 1 = An interrupt request from GPIO Port A6 or Comparator 0. [5] PA5CI Port A5 or Comparator 1 Interrupt Request 0 = No interrupt request is pending for GPIO Port A5 or Comparator 1. 1 = An interrupt request from GPIO Port A5 or Comparator 1. [4:1] PADxI Port A or Port D Pin x Interrupt Request 0 = No interrupt request is pending for GPIO Port A or Port D pin x. 1 = An interrupt request from GPIO Port A or Port D pin x is awaiting service; x indicates the specific GPIO port pin number (1–4). [0] PA0I Port A Pin 0 Interrupt Request 0 = No interrupt request is pending for GPIO Port A0. 1 = An interrupt request from GPIO Port A0 is awaiting service. For interrupt source select description, see the Shared Interrupt Select Register section on page 82. PS025016-1013 PRELIMINARY Interrupt Controller Z8 Encore! XP® F1680 Series Product Specification 75 8.4.3. Interrupt Request 2 Register The Interrupt Request 2 (IRQ2) Register, shown in Table 39, stores interrupt requests for both vectored and polled interrupts. When a request is presented to the interrupt controller, the corresponding bit in the IRQ2 Register becomes 1. If interrupts are globally enabled (vectored interrupts), the interrupt controller passes an interrupt request to the eZ8 CPU. If interrupts are globally disabled (polled interrupts), the eZ8 CPU can read the Interrupt Request 2 register to determine if any interrupt requests are pending. Table 39. Interrupt Request 2 Register (IRQ2) Bits 7 6 5 4 3 2 1 0 Field Reserved MCTI U1RXI U1TXI PC3I PC2I PC1I PC0I Reset 0 0 0 0 0 0 0 0 R/W R/W R/W R/W R/W R/W R/W R/W R/W Address FC6h Bit Description [7] Reserved; must be 0. [6] MCTI Multi-channel timer Interrupt Request 0 = No interrupt request is pending for multi-channel timer. 1 = An interrupt request from multi-channel timer is awaiting service. [5] U1RXI UART 1 Receiver Interrupt Request 0 = No interrupt request is pending for the UART 1 receiver. 1 = An interrupt request from the UART 1 receiver is awaiting service. [4] U1TXI UART 1 Transmitter Interrupt Request 0 = No interrupt request is pending for the UART 1 transmitter. 1 = An interrupt request from the UART 1 transmitter is awaiting service. [3:0] PCxI Port C Pin x Interrupt Request 0 = No interrupt request is pending for GPIO Port C pin x. 1 = An interrupt request from GPIO Port C pin x is awaiting service; x indicates the specific GPIO Port C pin number (0–3). PS025016-1013 PRELIMINARY Interrupt Controller Z8 Encore! XP® F1680 Series Product Specification 76 8.4.4. IRQ0 Enable High and Low Bit Registers Table 40 describes the priority control for IRQ0. The IRQ0 Enable High and Low Bit registers, shown in Tables 41 and 42, form a priority-encoded enabling for interrupts in the Interrupt Request 0 Register. Priority is generated by setting bits in each register. Table 40. IRQ0 Enable and Priority Encoding IRQ0ENH[x] IRQ0ENL[x] Priority Description 0 0 Disabled Disabled 0 1 Level 1 Low 1 0 Level 2 Nominal 1 1 Level 3 High Note: x indicates the register bits from 0–7. Table 41. IRQ0 Enable High Bit Register (IRQ0ENH) Bits 7 6 5 4 3 2 1 0 Field T2ENH T1ENH T0ENH U0RENH U0TENH I2CENH SPIENH ADCENH Reset 0 0 0 0 0 0 0 0 R/W R/W R/W R/W R/W R/W R/W R/W R/W Address FC1h Bit Description [7] T2ENH Timer 2 Interrupt Request Enable High Bit [6] T1ENH Timer 1 Interrupt Request Enable High Bit [5] T0ENH Timer 0 Interrupt Request Enable High Bit [4] UART 0 Receive Interrupt Request Enable High Bit U0RENH [3] UART 0 Transmit Interrupt Request Enable High Bit U0TENH [2] I2CENH I2C Interrupt Request Enable High Bit [1] SPIENH SPI Interrupt Request Enable High Bit [0] ADC Interrupt Request Enable High Bit ADCENH PS025016-1013 PRELIMINARY Interrupt Controller Z8 Encore! XP® F1680 Series Product Specification 77 Table 42. IRQ0 Enable Low Bit Register (IRQ0ENL) Bits 7 6 5 4 3 2 1 0 Field T2ENL T1ENL T0ENL U0RENL U0TENL I2CENL SPIENL ADCENL Reset 0 0 0 0 0 0 0 0 R/W R/W R/W R/W R/W R/W R/W R/W R/W Address FC2h Bit Description [7] T2ENL Timer 2 Interrupt Request Enable Low Bit [6] T1ENL Timer 1 Interrupt Request Enable Low Bit [5] T0ENL Timer 0 Interrupt Request Enable Low Bit [4] UART 0 Receive Interrupt Request Enable Low Bit U0RENL [3] UART 0 Transmit Interrupt Request Enable Low Bit U0TENL [2] I2CENL I2C Interrupt Request Enable Low Bit [1] SPIENL SPI Interrupt Request Enable Low Bit [0] ADC Interrupt Request Enable Low Bit ADCENL 8.4.5. IRQ1 Enable High and Low Bit Registers Table 43 lists the priority control for IRQ1. The IRQ1 Enable High and Low Bit registers, shown in Tables 44 and 45) form a priority-encoded enabling for interrupts in the Interrupt Request 1 Register. Priority is generated by setting bits in each register. Table 43. IRQ1 Enable and Priority Encoding IRQ1ENH[x] IRQ1ENL[x] Priority Description 0 0 Disabled Disabled 0 1 Level 1 Low 1 0 Level 2 Nominal 1 1 Level 3 High Note: An x indicates the register bits from 0–7. PS025016-1013 PRELIMINARY Interrupt Controller Z8 Encore! XP® F1680 Series Product Specification 78 Table 44. IRQ1 Enable High Bit Register (IRQ1ENH) Bits Field 7 Reset R/W 6 5 4 3 2 1 0 PA7VENH PA6C0ENH PA5C1ENH PAD4ENH PAD3ENH PAD2ENH PAD1ENH PA0ENH 0 0 0 0 0 0 0 0 R/W R/W R/W R/W R/W R/W R/W R/W Address FC4h Bit Description [7] PA7VENH Port A Bit[7] or LVD Interrupt Request Enable High Bit. [6] Port A Bit[6] or Comparator 0 Interrupt Request Enable High Bit. PA6C0ENH [5] Port A Bit[5] or Comparator 1 Interrupt Request Enable High Bit. PA5C1ENH [4:1] PADxENH Port A or Port D Bit[x] (x=1, 2, 3, 4) Interrupt Request Enable High Bit. [0] PA0ENH Port A Bit[0] Interrupt Request Enable High Bit. See the Shared Interrupt Select Register (IRQSS) on page 82 to determine a selection of either Port A or Port D as the interrupt source. PS025016-1013 PRELIMINARY Interrupt Controller Z8 Encore! XP® F1680 Series Product Specification 79 Table 45. IRQ1 Enable Low Bit Register (IRQ1ENL) Bits Field 7 5 4 3 2 1 0 PA7VENL PA6C0ENL PA5C1ENL PAD4ENL PAD3ENL PAD2ENL PAD1ENL Reset R/W 6 PA0ENL 0 0 0 0 0 0 0 0 R/W R/W R/W R/W R/W R/W R/W R/W Address FC5h Bit Description [7] PA7VENL Port A Bit[7] or LVD Interrupt Request Enable Low Bit. [6] Port A Bit[6] or Comparator 0 Interrupt Request Enable Low Bit. PA6C0ENL [5] Port A Bit[5] or Comparator 1 Interrupt Request Enable Low Bit. PA5C1ENL [4:1] PADxENL Port A or Port D Bit[x] (x=1, 2, 3, 4) Interrupt Request Enable Low Bit. [0] PA0ENL Port A Bit[0] Interrupt Request Enable Low Bit. 8.4.6. IRQ2 Enable High and Low Bit Registers Table 46 describes the priority control for IRQ2. The IRQ2 Enable High and Low Bit registers, shown in Tables 47 and 48 form a priority-encoded enabling for interrupts in the Interrupt Request 2 Register. Priority is generated by setting bits in each register. Table 46. IRQ2 Enable and Priority Encoding IRQ2ENH[x] IRQ2ENL[x] Priority Description 0 0 Disabled Disabled 0 1 Level 1 Low 1 0 Level 2 Nominal 1 1 Level 3 High Note: An x indicates the register bits from 0–7. PS025016-1013 PRELIMINARY Interrupt Controller Z8 Encore! XP® F1680 Series Product Specification 80 Table 47. IRQ2 Enable High Bit Register (IRQ2ENH) Bits Field 7 Reserved MCTENH 5 4 3 2 1 0 U1RENH U1TENH C3ENH C2ENH C1ENH C0ENH 0 0 0 0 0 0 0 0 R/W R/W R/W R/W R/W R/W R/W R/W Reset R/W 6 Address FC7h Bit Description [7] Reserved; must be 0. [6] Multi-Channel Timer Interrupt Request Enable High Bit MCTENH [5] UART1 Receive Interrupt Request Enable High Bit U1RENH [4] UART1 Transmit Interrupt Request Enable High Bit U1TENH [3] C3ENH Port C3 Interrupt Request Enable High Bit [2] C2ENH Port C2 Interrupt Request Enable High Bit [1] C1ENH Port C1 Interrupt Request Enable High Bit [0] C0ENH Port C0 Interrupt Request Enable High Bit PS025016-1013 PRELIMINARY Interrupt Controller Z8 Encore! XP® F1680 Series Product Specification 81 Table 48. IRQ2 Enable Low Bit Register (IRQ2ENL) Bits 7 6 5 4 3 2 1 0 Field Reserved MCTENL U1RENL U1TENL C3ENL C2ENL C1ENL C0ENL Reset 0 0 0 0 0 0 0 0 R/W R/W R/W R/W R/W R/W R/W R/W R/W Address FC8h Bit Description [7] Reserved; must be 0. [6] Multi-Channel Timer Interrupt Request Enable Low Bit (MCTENL) MCTENL [5] UART1 Receive Interrupt Request Enable Low Bit (U1RENL) U1RENL [4] UART1 Transmit Interrupt Request Enable Low Bit (U1TENL) U1TENL [3] C3ENL Port C3 Interrupt Request Enable Low Bit (C3ENL) [2] C2ENL Port C2 Interrupt Request Enable Low Bit (C2ENL) [1] C1ENL Port C1 Interrupt Request Enable Low Bit (C1ENL) [0] C0ENL Port C0 Interrupt Request Enable Low Bit (C0ENL) PS025016-1013 PRELIMINARY Interrupt Controller Z8 Encore! XP® F1680 Series Product Specification 82 8.4.7. Interrupt Edge Select Register The Interrupt Edge Select (IRQES) Register, shown in Table 49, determines whether an interrupt is generated for the rising edge or falling edge on the selected GPIO Port A or Port D input pin. Table 49. Interrupt Edge Select Register (IRQES) Bits 7 6 5 4 3 2 1 0 Field IES7 IES6 IES5 IES4 IES3 IES2 IES1 IES0 Reset 0 0 0 0 0 0 0 0 R/W R/W R/W R/W R/W R/W R/W R/W R/W Address FCDh Bit Description [7:0] IESx Interrupt Edge Select x 0 = An interrupt request is generated on the falling edge of the PAx input or PDx input. 1 = An interrupt request is generated on the rising edge of the PAx input or PDx input; x indicates the specific GPIO port pin number (0–7). 8.4.8. Shared Interrupt Select Register The Shared Interrupt Select (IRQSS) Register, shown in Table 50, determines the source of the PADxS interrupts. The Shared Interrupt Select Register selects between Port A and alternate sources for the individual interrupts. Table 50. Shared Interrupt Select Register (IRQSS) Bits 7 6 5 4 3 2 1 0 Field PA7VS PA6CS PA5CS PAD4S PAD3S PAD2S PAD1S Reserved Reset 0 0 0 0 0 0 0 0 R/W R/W R/W R/W R/W R/W R/W R/W R/W Address FCEh Bit Description [7] PA7VS PA7/LVD Selection 0 = PA7 is used for the interrupt for PA7VS interrupt request. 1 = The LVD is used for the interrupt for PA7VS interrupt request. [6] PA6CS PA6/Comparator 0 Selection 0 = PA6 is used for the interrupt for PA6CS interrupt request. 1 = The Comparator 0 is used for the interrupt for PA6CS interrupt request. PS025016-1013 PRELIMINARY Interrupt Controller Z8 Encore! XP® F1680 Series Product Specification 83 Bit Description [5] PA5CS PA5/Comparator 1 Selection 0 = PA5 is used for the interrupt for PA5CS interrupt request. 1 = The Comparator 1 is used for the interrupt for PA5CS interrupt request. [4:1] PADxS PAx/PDx Selection 0 = PAx is used for the interrupt for PAx/PDx interrupt request 1 = PDx is used for the interrupt for PAx/PDx interrupt request; an x indicates the specific GPIO port pin number (1–4). [0] Reserved; must be 0. 8.4.9. Interrupt Control Register The Interrupt Control (IRQCTL) Register, shown in Table 51, contains the master enable bit for all interrupts. Table 51. Interrupt Control Register (IRQCTL) Bits 7 Field IRQE Reset R/W 6 5 4 0 0 0 0 R/W R R R 3 2 1 0 0 0 0 0 R R R R Reserved Address FCFh Bit Description [7] IRQE Interrupt Request Enable This bit is set to 1 by executing an Enable Interrupts (EI) or IRET (Interrupt Return) instruction, or by a direct register write of a 1 to this bit. It is reset to 0 by executing a DI instruction, eZ8 CPU acknowledgement of an interrupt request, a Reset, or by a direct register write of a 0 to this bit. 0 = Interrupts are disabled. 1 = Interrupts are enabled. [6:0] Reserved; must be 0. PS025016-1013 PRELIMINARY Interrupt Controller Z8 Encore! XP® F1680 Series Product Specification 84 Chapter 9. Timers The Z8 Encore! XP F1680 Series products contain three 16-bit reloadable timers that can be used for timing, event counting, or generation of pulse-width modulated signals. The timers’ features include: • • • • • • 16-bit reload counter • • • • Timer output pin Programmable prescaler with prescale values ranging from 1 to 128 PWM output generation Capture and compare capability Two independent capture/compare channels which reference the common timer External input pin for timer input, clock gating, or capture signal. External input pin signal frequency is limited to a maximum of one-fourth the timer clock frequency Timer interrupt Noise Filter on Timer input signal Operation in any mode with 32 kHz secondary oscillator In addition to the timers described in this chapter, the Baud Rate Generator (BRG) of unused UART peripheral can also be used to provide basic timing functionality. For more information about using the Baud Rate Generator as additional timers, see the LIN-UART chapter on page 144. PS025016-1013 PRELIMINARY Timers Z8 Encore! XP® F1680 Series Product Specification 85 9.1. Architecture Figure 11 displays the architecture of the timers. Timer Block Block Control 16-bit Reload Register Peripheral Clock System Clock Timer Input Compare Timer Control Data Bus Gate Input Capture Input Two 16-bit PWM/Compare Timer Interrupt TOUT TOUT Compare 16-bit Counter with Prescaler Interrupt, PWM, and Timer Output Control Figure 11. Timer Block Diagram 9.2. Operation The timers are 16-bit up-counters. Minimum time-out delay is set by loading the value 0001h into the Timer Reload High and Low Byte registers and setting the prescale value to 1. Maximum time-out delay is set by loading the value 0000h into the Timer Reload High and Low Byte registers and setting the prescale value to 128. If the Timer reaches FFFFh, the timer rolls over to 0000h and continues counting. 9.2.1. Timer Clock Source The timer clock source can come from either the peripheral clock or the system clock. Peripheral clock is based on a low frequency/low power 32 kHz secondary oscillator that can be used with external watch crystal. Peripheral clock source is only available for driving Timer and Noise Filter operation. It is not supported for other peripherals. For timer operation in STOP Mode, peripheral clock must be selected as the clock source. Peripheral clock can be selected as source for both ACTIVE and STOP Mode operation. PS025016-1013 PRELIMINARY Timers Z8 Encore! XP® F1680 Series Product Specification 86 System clock is only for operation in ACTIVE and HALT modes. System clock is software selectable in Oscillator Control Module as external high-frequency crystal or internal precision oscillator. The TCLKS field in the Timer Control 2 Register selects the timer clock source. Caution: When the timer is operating on a peripheral clock, the timer clock is asynchronous to the CPU clock. To ensure error-free operation, disable the timer before modifying its operation (also include changing the timer clock source). Therefore, any write to the timer control registers cannot be performed when the timer is enabled and a peripheral clock is used. When the timer uses a peripheral clock and the timer is enabled, any read from TxH or TxL is not recommended, because the results can be unpredictable. Disable the timer first, then read it. If the timer works in the CAPTURE, CAPTURE/COMPARE, CAPTURE RESTART or DEMODULATION modes, any read from TxPWM0h, TxPWM0L, TxPWM1h, TxPWM1L or TxSTAT must be performed after a capture interrupt occurs; otherwise, results can be unpredictable. The INPCAP bit of the Timer Control 0 Register is the same as these PWM registers. When the timer uses the main clock, you can write/ read all timer registers at any time. 9.2.2. Low-Power Modes Timers can operate in both HALT Mode and STOP Mode. 9.2.2.1. Operation in HALT Mode When the eZ8 CPU enters HALT Mode, the timer will continue to operate if enabled. To minimize current in HALT Mode, the timer can be disabled by clearing the TEN control bit. The noise filter, if enabled, will also continue to operate in HALT Mode and rejects any noise on the timer input pin. 9.2.2.2. Operation in STOP Mode When the eZ8 CPU enters STOP Mode, the timer continues to operate if enabled and peripheral clock is chosen as the clock source. In STOP Mode, the timer interrupt (if enabled) automatically initiates a Stop Mode Recovery and generates an interrupt request. In the Reset Status Register, the stop bit is set to 1. Also, timer interrupt request bit in Interrupt Request 0 register is set. Following completion of the Stop Mode Recovery, if interrupts are enabled, the CPU responds to the interrupt request by fetching the timer interrupt vector. The noise filter, if enabled, will also continue to operate in STOP Mode and rejects any noise on the timer input pin. PS025016-1013 PRELIMINARY Timers Z8 Encore! XP® F1680 Series Product Specification 87 If system clock is chosen as the clock source, the timer ceases to operate as a system clock and is put into STOP Mode. In this case the registers are not reset and operation will resume after Stop Mode Recovery occurs. 9.2.2.3. Power Reduction During Operation Removal of the TEN bit will inhibit clocking of the entire timer block. The CPU can still read/write registers when the enable bit(s) are taken out. 9.2.3. Timer Operating Modes The timers can be configured to operate in the following modes, each of which is described in this section where indicated in Table 52. Table 52. Timer Operating Modes Page Number Mode TRIGGERED ONE-SHOT Mode 88 CONTINUOUS Mode 90 COUNTER Mode 91 COMPARATOR COUNTER Mode 92 PWM SINGLE OUTPUT Mode 93 PWM DUAL Output Mode 95 CAPTURE Mode 97 CAPTURE RESTART Mode 98 COMPARE Mode 100 GATED Mode 100 CAPTURE/COMPARE Mode 102 DEMODULATION Mode 103 9.2.3.1. ONE-SHOT Mode In ONE-SHOT Mode, the timer counts up to the 16-bit reload value stored in the Timer Reload High and Low Byte registers. The Timer counts timer clocks up to the 16-bit reload value. Upon reaching the reload value, the timer generates an interrupt, and the count value in the Timer High and Low Byte registers is reset to 0001h. Then, the timer is automatically disabled and stops counting. Additionally, if the Timer Output alternate function is enabled, the Timer Output pin changes state for one clock cycle (from Low to High or from High to Low) upon timer reload. If it is appropriate to have the Timer Output make a permanent state change on PS025016-1013 PRELIMINARY Timers Z8 Encore! XP® F1680 Series Product Specification 88 One-Shot time-out. First set the TPOL bit in the Timer Control 1 Register to the start value before beginning ONE-SHOT Mode. Then, after starting the timer, set TPOL to the opposite bit value. Observe the following steps to configure a timer for ONE-SHOT Mode and to initiate the count: 1. Write to the Timer Control 1 Register to: – Disable the timer – Configure the timer for ONE-SHOT Mode – Set the prescale value – If using the Timer Output alternate function, set the initial output level (High or Low) 2. Write to the Timer Control 2 Register to choose the timer clock source. 3. Write to the Timer Control 0 Register to set the timer interrupt configuration field TICONFIG. 4. Write to the Timer High and Low Byte registers to set the starting count value. 5. Write to the Timer Reload High and Low Byte registers to set the reload value. 6. If required, enable the timer interrupt and set the timer interrupt priority by writing to the relevant interrupt registers. 7. If using the Timer Output function, configure the associated GPIO port pin for the Timer Output alternate function. 8. Write to the Timer Control 1 Register to enable the timer and initiate counting. In ONE-SHOT Mode, the timer clock always provides the timer input. The timer period is calculated using the following equation: Value - Start Value xPrescale ONE-SHOT Mode Time-Out Period (s) = Reload ------------------------------------------------------------------------------------------Timer Clock Frequency (Hz) 9.2.3.2. TRIGGERED ONE-SHOT Mode In TRIGGERED ONE-SHOT Mode, the timer operates in the following sequence: 1. The Timer idles until a trigger is received. The Timer trigger is taken from the GPIO port pin timer input alternate function. The TPOL bit in the Timer Control 1 Register selects whether the trigger occurs on the rising edge or the falling edge of the timer input signal. 2. Following the trigger event, the Timer counts timer clocks up to the 16-bit reload value stored in the Timer Reload High and Low Byte registers. PS025016-1013 PRELIMINARY Timers Z8 Encore! XP® F1680 Series Product Specification 89 3. Upon reaching the reload value, the timer outputs a pulse on the Timer Output pin, generates an interrupt and resets the count value in the Timer High and Low Byte registers to 0001h. The period of the output pulse is a single timer clock. The TPOL bit also sets the polarity of the output pulse. 4. The Timer now idles until the next trigger event. In TRIGGERED ONE-SHOT Mode, the timer clock always provides the timer input. The timer period is shown in the following equation:  Reload Value - Start Value   Prescale Triggered ONE-SHOT Mode Time-Out Period (s) = -----------------------------------------------------------------------------------------------Timer Clock Frequency (Hz) Table 53 provides an example initialization sequence for configuring Timer 0 in TRIGGERED ONE-SHOT Mode and initiating operation. Table 53. TRIGGERED ONE-SHOT Mode Initialization Example Register Value Comment T0CTL0 E0h T0CTL1 03h T0CTL2 01h TMODE[3:0] = 1011B selects TRIGGERED ONE-SHOT Mode. TICONFIG[1:0] = 11B enables interrupts on Timer reload only. CSC = 0 selects the Timer Input (Trigger) from the GPIO pin. PWMD[2:0] = 000B has no effect. INPCAP = 0 has no effect. TEN = 0 disables the timer. TPOL = 0 enables triggering on rising edge of Timer. Input and sets Timer Out signal to 0. PRES[2:0] = 000B sets prescaler to divide by 1. TCLKS = 1 sets 32 kHz peripheral clock as the Timer clock source. T0h 00h T0L 01h T0RH ABh T0RL CDh PAADDR 02h Selects Port A Alternate Function control register. PACTL[1:0] 11b PACTL[0] enables Timer 0 Input Alternate function. PACTL[1] enables Timer 0 Output Alternate function. IRQ0ENH[5] 0B Disables the Timer 0 interrupt. IRQ0ENL[5] 0B PS025016-1013 Timer starting value = 0001h. Timer reload value = ABCDh. PRELIMINARY Timers Z8 Encore! XP® F1680 Series Product Specification 90 Table 53. TRIGGERED ONE-SHOT Mode Initialization Example (Continued) Register Value Comment T0CTL1 83h TEN = 1 enables the timer. All other bits remain in their appropriate settings. Note: After receiving the input trigger, Timer 0 will: 1. Count ABCDh timer clocks. 2. Upon Timer 0 reload, generate single clock cycle active High output pulse on Timer 0 Output pin. 3. Wait for next input trigger event. 9.2.3.3. CONTINUOUS Mode In CONTINUOUS Mode, the timer counts up to the 16-bit reload value stored in the Timer Reload High and Low Byte registers. The Timer counts timer clocks up to the 16bit reload value. Upon reaching the reload value, the timer generates an interrupt, the count value in the Timer High and Low Byte registers is reset to 0001h and counting resumes. Also, if the Timer Output alternate function is enabled, the Timer Output pin changes state (from Low to High or High to Low) on timer reload. Observe the following steps to configure a timer for CONTINUOUS Mode and initiate the count: 1. Write to the Timer Control 1 Register to: – Disable the timer – Configure the timer for CONTINUOUS Mode – Set the prescale value – If using the Timer Output Alternate Function, set the initial output level (High or Low) 2. Write to the Timer Control 2 Register to choose the timer clock source. 3. Write to the Timer Control 0 Register to set the timer interrupt-configuration field TICONFIG. 4. Write to the Timer High and Low Byte registers to set the starting count value (usually 0001h). This value only affects the first pass in CONTINUOUS Mode. After the first timer reload in CONTINUOUS Mode, counting always begins at the reset value of 0001h. 5. Write to the Timer Reload High and Low Byte registers to set the reload value. 6. If appropriate, enable the timer interrupt and set the timer interrupt priority by writing to the relevant interrupt registers. 7. If using the Timer Output function, configure the associated GPIO port pin for the Timer Output alternate function. 8. Write to the Timer Control 1 Register to enable the timer and initiate counting. PS025016-1013 PRELIMINARY Timers Z8 Encore! XP® F1680 Series Product Specification 91 In CONTINUOUS Mode, the timer clock always provides the timer input. The timer period is calculated using the following equation: Reload Value  Prescale CONTINUOUS Mode Time-Out Period (s) = --------------------------------------------------------------------Timer Clock Frequency (Hz) If an initial starting value other than 0001h is loaded into the Timer High and Low Byte registers, the ONE-SHOT Mode equation must be used to determine the first time-out period. 9.2.3.4. COUNTER Mode In COUNTER Mode, the timer counts input transitions from a GPIO port pin. The timer input is taken from the GPIO port pin Timer Input alternate function. The TPOL bit in the Timer Control 1 Register selects whether the count occurs on the rising edge or the falling edge of the Timer Input signal. In COUNTER Mode, the prescaler is disabled. Caution: The input frequency of the Timer Input signal must not exceed one-fourth the timer clock frequency. Upon reaching the reload value stored in the Timer Reload High and Low Byte registers, the timer generates an interrupt, the count value in the Timer High and Low Byte registers is reset to 0001h and counting resumes. Also, if the Timer Output alternate function is enabled, the Timer Output pin changes state (from Low to High or High to Low) at timer reload. Observe the following steps to configure a timer for COUNTER Mode and initiate the count: 1. Write to the Timer Control 1 Register to: – Disable the timer. – Configure the timer for COUNTER Mode. – Select either the rising edge or falling edge of the Timer Input signal for the count. This also sets the initial logic level (High or Low) for the Timer Output Alternate Function. However, the Timer Output function is not required to be enabled. 2. Write to the Timer Control 2 Register to choose the timer clock source. PS025016-1013 PRELIMINARY Timers Z8 Encore! XP® F1680 Series Product Specification 92 3. Write to the Timer Control 0 Register to set the timer interrupt configuration field TICONFIG. 4. Write to the Timer High and Low Byte registers to set the starting count value. This value only affects the first pass in COUNTER Mode. After the first timer reload in COUNTER Mode, counting always begins at the reset value of 0001h. Generally, in COUNTER Mode the Timer High and Low Byte registers must be written with the value 0001h. 5. Write to the Timer Reload High and Low Byte registers to set the reload value. 6. If required, enable the timer interrupt and set the timer interrupt priority by writing to the relevant interrupt registers. 7. Configure the associated GPIO port pin for the Timer Input alternate function. 8. When using the Timer Output function, configure the associated GPIO port pin for the Timer Output alternate function. 9. Write to the Timer Control 1 Register to enable the timer. In COUNTER Mode, the number of Timer Input transitions since the timer start is calculated using the following equation: COUNTER Mode Timer Input Transitions = Current Count Value - Start Value 9.2.3.5. COMPARATOR COUNTER Mode In COMPARATOR COUNTER Mode, the timer counts output transitions from an analog comparator output. The assignment of a comparator to a timer is based on the TIMTRG bits in the CMP0 and CMP1 registers. The TPOL bit in the Timer Control 1 Register selects whether the count occurs on the rising edge or the falling edge of the comparator output signal. In COMPARATOR COUNTER Mode, the prescaler is disabled. Caution: The frequency of the comparator output signal must not exceed one-fourth the timer clock frequency. Upon reaching the reload value stored in the Timer Reload High and Low Byte registers, the timer generates an interrupt, the count value in the Timer High and Low Byte registers is reset to 0001h and counting resumes. Also, if the Timer Output alternate function is enabled, the Timer Output pin changes state (from Low to High or High to Low) at timer reload. Observe the following steps to configure a timer for COMPARATOR COUNTER Mode and initiate the count: PS025016-1013 PRELIMINARY Timers Z8 Encore! XP® F1680 Series Product Specification 93 1. Write to the Timer Control 1 Register to: – Disable the timer. – Configure the timer for COMPARATOR COUNTER Mode. – Select either the rising edge or falling edge of the comparator output signal for the count. This also sets the initial logic level (High or Low) for the Timer Output alternate function. The Timer Output function does not have to be enabled. 2. Write to the appropriate comparator control register (COMP0 or COMP1) to set the TIMTRG bits that map the comparator to the timer. 3. Write to the Timer Control 2 Register to choose the timer clock source. 4. Write to the Timer Control 0 Register to set the timer interrupt configuration field TICONFIG. 5. Write to the Timer High and Low Byte registers to set the starting count value. This value only affects the first pass in COMPARATOR COUNTER Mode. After the first timer reload in COMPARATOR COUNTER Mode, counting always begins at the reset value of 0001h. Generally, in COMPARATOR COUNTER Mode the Timer High and Low Byte registers must be written with the value 0001h. 6. Write to the Timer Reload High and Low Byte registers to set the reload value. 7. If required, enable the timer interrupt and set the timer interrupt priority by writing to the relevant interrupt registers. 8. If using the Timer Output function, configure the associated GPIO port pin for the Timer Output alternate function. 9. Write to the Timer Control 1 Register to enable the timer. In COMPARATOR COUNTER Mode, the number of comparator output transitions since the timer start is calculated using the following equation: Comparator Output Transitions = Current Count Value - Start Value 9.2.3.6. PWM SINGLE OUTPUT Mode In PWM SINGLE OUTPUT Mode, the timer outputs a Pulse Width Modulator output signal through a GPIO port pin. The Timer counts timer clocks up to the 16-bit reload value. The timer first counts up to the 16-bit PWM match value stored in the Timer PWM0 High and Low Byte registers. When the timer count value matches the PWM value, the Timer Output toggles. The timer continues counting until it reaches the reload value stored in the Timer Reload High and Low Byte registers. Upon reaching the reload value, the timer generates an interrupt, the count value in the Timer High and Low Byte registers is reset to 0001h and counting resumes. PS025016-1013 PRELIMINARY Timers Z8 Encore! XP® F1680 Series Product Specification 94 If the TPOL bit in the Timer Control 1 Register is set to 1, the Timer Output signal begins as High (1) and then transitions to Low (0) when the timer value matches the PWM value. The Timer Output signal returns to High (1) after the timer reaches the reload value and is reset to 0001h. If the TPOL bit in the Timer Control 1 Register is set to 0, the Timer Output signal begins as Low (0) and then transitions to High (1) when the timer value matches the PWM value. The Timer Output signal returns to Low (0) after the timer reaches the reload value and is reset to 0001h. Observe the following steps to configure a timer for PWM SINGLE OUTPUT Mode and initiate PWM operation: 1. Write to the Timer Control 1 Register to: – Disable the timer – Configure the timer for PWM mode – Set the prescale value – Set the initial logic level (High or Low) and PWM High/Low transition for the Timer Output Alternate Function 2. Write to the Timer Control 2 Register to choose the timer clock source. 3. Write to the Timer Control 0 Register to set the timer interrupt configuration field TICONFIG. 4. Write to the Timer High and Low Byte registers to set the starting count value (typically 0001h). This value only affects the first pass in PWM mode. After the first timer reset in PWM mode, counting always begins at the reset value of 0001h. 5. Write to the Timer PWM0 High and Low Byte registers to set the PWM value. 6. Write to the Timer Reload High and Low Byte registers to set the reload value (PWM period). The reload value must be greater than the PWM value. 7. If appropriate, enable the timer interrupt and set the timer interrupt priority by writing to the relevant interrupt registers. 8. Configure the associated GPIO port pin for the Timer Output alternate function. 9. Write to the Timer Control 1 Register to enable the timer and initiate counting. The PWM period is calculated using the following equation: If an initial starting value other than 0001h is loaded into the Timer High and Low Byte registers, the ONE-SHOT Mode equation must be used to determine the first PWM timeout period. PS025016-1013 PRELIMINARY Timers Z8 Encore! XP® F1680 Series Product Specification 95 Reload Value  Prescale PWM Period (s) = --------------------------------------------------------------------Timer Clock Frequency (Hz) If TPOL is set to 0, the ratio of the PWM output High time to the total period is calculated using the following equation: Reload Value - PWM Value PWM Output High Time Ratio (%) = --------------------------------------------------------------------  100 Reload Value If TPOL is set to 1, the ratio of the PWM output High time to the total period is calculated using the following equation: PWM Value PWM Output High Time Ratio (%) = --------------------------------  100 Reload Value 9.2.3.7. PWM DUAL Output Mode In PWM DUAL OUTPUT Mode, the timer outputs a Pulse Width Modulator output signal and also its complement through two GPIO port pins. The timer first counts up to the 16bit PWM match value stored in the Timer PWM0 High and Low Byte registers. When the timer count value matches the PWM value, the Timer Outputs (TOUT and TOUT) toggle. The timer continues counting until it reaches the reload value stored in the Timer Reload High and Low Byte registers. Upon reaching the reload value, the timer generates an interrupt, the count value in the Timer High and Low Byte registers is reset to 0001h and TOUT and TOUT toggles again and counting resumes. If the TPOL bit in the Timer Control 1 Register is set to 1, the Timer Output signal begins as High (1) and then transitions to Low (0) when the timer value matches the PWM value. The Timer Output signal returns to High (1) after the timer reaches the reload value and is reset to 0001h. If the TPOL bit in the Timer Control 1 Register is set to 0, the Timer Output signal begins as Low (0) and then transitions to High (1) when the timer value matches the PWM value. The Timer Output signal returns to Low (0) after the timer reaches the reload value and is reset to 0001h. The timer also generates a second PWM output signal, Timer Output Complement (TOUT). TOUT is the complement of the Timer Output PWM signal (TOUT). A programmable deadband delay can be configured to set a time delay (0 to 128 timer clock cycles) when one PWM output transitions from High to Low and the other PWM output PS025016-1013 PRELIMINARY Timers Z8 Encore! XP® F1680 Series Product Specification 96 transitions from a Low to High. This configuration ensures a time gap between the removal of one PWM output and the assertion of its complement. Observe the following steps to configure a timer for PWM DUAL OUTPUT Mode and initiate the PWM operation: 1. Write to the Timer Control 1 Register to: – Disable the timer – Configure the timer for PWM DUAL OUTPUT Mode. Setting the mode also involves writing to TMODE[3] bit in the TxCTL0 Register – Set the prescale value – Set the initial logic level (High or Low) and PWM High/Low transition for the Timer Output Alternate Function 2. Write to the Timer High and Low Byte registers to set the starting count value (typically 0001h). This value only affects the first pass in PWM mode. After the first timer reset in PWM mode, counting always begins at the reset value of 0001h. 3. Write to the Timer PWM0 High and Low Byte registers to set the PWM value. 4. Write to the Timer Control 0 Register: – To set the PWM deadband delay value – To choose the timer clock source 5. Write to the Timer Control 0 Register to set the timer interrupt configuration field TICONFIG. 6. Write to the Timer Reload High and Low Byte registers to set the reload value (PWM period). The reload value must be greater than the PWM value. 7. If appropriate, enable the timer interrupt and set the timer interrupt priority by writing to the relevant interrupt registers. 8. Configure the associated GPIO port pin for the Timer Output and Timer Output Complement alternate functions. 9. Write to the Timer Control 1 Register to enable the timer and initiate counting. The PWM period is calculated using the following equation: If an initial starting value other than 0001h is loaded into the Timer High and Low Byte registers, the ONE-SHOT Mode equation must be used to determine the first PWM timeout period. If TPOL is set to 0, the ratio of the PWM output High time to the total period is calculated using the following equation: PS025016-1013 PRELIMINARY Timers Z8 Encore! XP® F1680 Series Product Specification 97 Reload Value  Prescale PWM Period (s) = ----------------------------------------------------------------------Timer Clock Frequency (Hz) Reload Value - PWM Value PWM Output High Time Ratio (%) = --------------------------------------------------------------------  100 Reload Value If TPOL is set to 1, the ratio of the PWM output High time to the total period is calculated using the following equation: PWM Value PWM Output High Time Ratio (%) = --------------------------------  100 Reload Value 9.2.3.8. CAPTURE Mode In CAPTURE Mode, the current timer count value is recorded when the appropriate external Timer Input transition occurs. The Capture count value is written to the Timer PWM0 High and Low Byte registers. The Timer counts timer clocks up to the 16-bit reload value. The TPOL bit in the Timer Control 1 Register determines if the Capture occurs on a rising edge or a falling edge of the Timer Input signal. When the Capture event occurs, an interrupt is generated and the timer continues counting. The INPCAP bit in Timer Control 0 Register is set to indicate the timer interrupt is due to an input capture event. The timer continues counting up to the 16-bit reload value stored in the Timer Reload High and Low Byte registers. Upon reaching the reload value, the timer generates an interrupt and continues counting. The INPCAP bit in Timer Control 0 Register is cleared to indicate the timer interrupt is not due to an input capture event. Observe the following steps to configure a timer for CAPTURE Mode and initiate the count: 1. Write to the Timer Control 1 Register to: – Disable the timer – Configure the timer for CAPTURE Mode – Set the prescale value – Set the Capture edge (rising or falling) for the Timer Input 2. Write to the Timer Control 2 Register to choose the timer clock source. 3. Write to the Timer Control 0 Register to set the timer interrupt configuration field TICONFIG. PS025016-1013 PRELIMINARY Timers Z8 Encore! XP® F1680 Series Product Specification 98 4. Write to the Timer High and Low Byte registers to set the starting count value (typically 0001h). 5. Write to the Timer Reload High and Low Byte registers to set the reload value. 6. Clear the Timer PWM High and Low Byte registers to 0000h. This allows user software to determine if interrupts were generated by either a capture event or a reload. If the PWM High and Low Byte registers still contain 0000h after the interrupt, then the interrupt was generated by a Reload. 7. If required, enable the timer interrupt and set the timer interrupt priority by writing to the relevant interrupt registers. By default, the timer interrupt will be generated for both input capture and reload events. If required, configure the timer interrupt to be generated only at the input capture event or the reload event by setting TICONFIG field of the Timer Control 0 Register. 8. Configure the associated GPIO port pin for the Timer Input alternate function. 9. Write to the Timer Control 1 Register to enable the timer and initiate counting. In CAPTURE Mode, the elapsed time from timer start to Capture event can be calculated using the following equation:  Capture Value - Start Value   Prescale Capture Elapsed Time (s) = -------------------------------------------------------------------------------------------------Timer Clock Frequency (Hz) 9.2.3.9. CAPTURE RESTART Mode In CAPTURE RESTART Mode, the current timer count value is recorded when the appropriate external Timer Input transition occurs. The Capture count value is written to the Timer PWM High and Low Byte registers. The Timer counts timer clocks up to the 16bit reload value. The TPOL bit in the Timer Control 1 Register determines if the Capture occurs on a rising edge or a falling edge of the Timer Input signal. When the Capture event occurs, an interrupt is generated and the count value in the Timer High and Low Byte registers is reset to 0001h and counting resumes. The INPCAP bit in Timer Control 0 Register is set to indicate the timer interrupt is due to an input capture event. If no Capture event occurs, the timer counts up to the 16-bit Compare value stored in the Timer Reload High and Low Byte registers. Upon reaching the reload value, the timer generates an interrupt, the count value in the Timer High and Low Byte registers is reset to 0001h and counting resumes. The INPCAP bit in Timer Control 0 Register is cleared to indicate the timer interrupt is not due to an input capture event. PS025016-1013 PRELIMINARY Timers Z8 Encore! XP® F1680 Series Product Specification 99 Observe the following steps to configure a timer for CAPTURE RESTART Mode and initiate the count: 1. Write to the Timer Control 1 Register to: – Disable the timer – Configure the timer for CAPTURE RESTART Mode. Setting the mode also involves writing to TMODE[3] bit in the TxCTL0 Register – Set the prescale value – Set the Capture edge (rising or falling) for the Timer Input 2. Write to the Timer Control 2 Register to choose the timer clock source. 3. Write to the Timer Control 0 Register to set the timer interrupt configuration field TICONFIG. 4. Write to the Timer High and Low Byte registers to set the starting count value (typically 0001h). 5. Write to the Timer Reload High and Low Byte registers to set the reload value. 6. Clear the Timer PWM High and Low Byte registers to 0000h. This allows user software to determine if interrupts are generated by either a Capture Event or a Reload. If the PWM High and Low Byte registers still contain 0000h after the interrupt, then the interrupt is generated by a Reload. 7. If required, enable the timer interrupt and set the timer interrupt priority by writing to the relevant interrupt registers. By default, the timer interrupt will be generated for both input capture and reload events. If required, configure the timer interrupt to be generated only at the Input Capture event or the reload event by setting TICONFIG field of the Timer Control 0 Register. 8. Configure the associated GPIO port pin for the Timer Input alternate function. 9. Write to the Timer Control 1 Register to enable the timer and initiate counting. In CAPTURE Mode, the elapsed time from Timer start to Capture event can be calculated using the following equation:  Capture Value - Start Value   Prescale Capture Elapsed Time (s) = -------------------------------------------------------------------------------------------------Timer Clock Frequency (Hz) PS025016-1013 PRELIMINARY Timers Z8 Encore! XP® F1680 Series Product Specification 100 9.2.3.10. COMPARE Mode In COMPARE Mode, the timer counts up to the 16-bit maximum Compare value stored in the Timer Reload High and Low Byte registers. The Timer counts timer clocks up to a 16bit reload value. Upon reaching the Compare value, the timer generates an interrupt and counting continues (the timer value is not reset to 0001h). Also, if the Timer Output alternate function is enabled, the Timer Output pin changes state (from Low to High or from High to Low) on Compare. If the Timer reaches FFFFh, the timer rolls over to 0000h and continue counting. Observe the following steps to configure a timer for COMPARE Mode and initiate the count: 1. Write to the Timer Control 1 Register to: – Disable the timer – Configure the timer for COMPARE Mode – Set the prescale valu. – Set the initial logic level (High or Low) for the Timer Output alternate function, if required 2. Write to the Timer Control 2 Register to choose the timer clock source. 3. Write to the Timer Control 0 Register to set the timer interrupt configuration field TICONFIG. 4. Write to the Timer High and Low Byte registers to set the starting count value. 5. Write to the Timer Reload High and Low Byte registers to set the Compare value. 6. If appropriate, enable the timer interrupt and set the timer interrupt priority by writing to the relevant interrupt registers. 7. When using the Timer Output function, configure the associated GPIO port pin for the Timer Output alternate function. 8. Write to the Timer Control 1 Register to enable the timer and initiate counting. In COMPARE Mode, the timer clock always provides the timer input. The Compare time is calculated using the following equation: 9.2.3.11. GATED Mode In GATED Mode, the timer counts only when the Timer Input signal is in its active state (asserted) as determined by the TPOL bit in the Timer Control 1 Register. When the Timer Input signal is asserted, counting begins. A Timer Interrupt is generated when the Timer Input signal is deasserted or a timer reload occurs. To determine if a Timer Input signal PS025016-1013 PRELIMINARY Timers Z8 Encore! XP® F1680 Series Product Specification 101  Compare Value - Start Value   Prescale COMPARE Mode Time (s) = ----------------------------------------------------------------------------------------------------Timer Clock Frequency (Hz) generated the interrupt, read the associated GPIO input value and compare to the value stored in the TPOL bit. The timer counts up to the 16-bit reload value stored in the Timer Reload High and Low Byte registers. The timer input is the timer clock. When reaching the reload value, the timer generates an interrupt, the count value in the Timer High and Low Byte registers is reset to 0001h and counting resumes (assuming the Timer Input signal is still asserted). Also, if the Timer Output alternate function is enabled, the Timer Output pin changes state (from Low to High or from High to Low) at timer reset. Observe the following steps to configure a timer for GATED Mode and initiate the count: 1. Write to the Timer Control 1 Register to: – Disable the timer – Configure the timer for GATED Mode – Set the prescale value 2. Write to the Timer Control 2 Register to choose the timer clock source. 3. Write to the Timer Control 0 Register to set the timer interrupt configuration field TICONFIG. 4. Write to the Timer High and Low Byte registers to set the starting count value. This value only affects the first pass in GATED Mode. After the first timer reset in GATED Mode, counting always begins at the reset value of 0001h. 5. Write to the Timer Reload High and Low Byte registers to set the reload value. 6. If required, enable the timer interrupt and set the timer interrupt priority by writing to the relevant interrupt registers. By default, the timer interrupt will be generated for both input deassertion and reload events. If required, configure the timer interrupt to be generated only at the Input Deassertion event or the Reload event by setting TICONFIG field of the Timer Control 0 Register. 7. Configure the associated GPIO port pin for the Timer Input alternate function. 8. Write to the Timer Control 1 Register to enable the timer. 9. Assert the Timer Input signal to initiate the counting. PS025016-1013 PRELIMINARY Timers Z8 Encore! XP® F1680 Series Product Specification 102 9.2.3.12. CAPTURE/COMPARE Mode In CAPTURE/COMPARE Mode, the timer begins counting on the first external Timer Input transition. The appropriate transition (rising edge or falling edge) is set by the TPOL bit in the Timer Control 1 Register. The Timer counts timer clocks up to the 16-bit reload value. Every subsequent appropriate transition (after the first) of the Timer Input signal captures the current count value. The Capture value is written to the Timer PWM0 High and Low Byte registers. When the Capture event occurs, an interrupt is generated, the count value in the Timer High and Low Byte registers is reset to 0001h and counting resumes. The INPCAP bit in Timer Control 0 Register is set to indicate the timer interrupt is due to an input capture event. If no Capture event occurs, the timer counts up to the 16-bit Compare value stored in the Timer Reload High and Low Byte registers. Upon reaching the Compare value, the timer generates an interrupt, the count value in the Timer High and Low Byte registers is reset to 0001h and counting resumes. The INPCAP bit in Timer Control 0 Register is cleared to indicate the timer interrupt is not due to an input capture event. Observe the following steps to configure a timer for CAPTURE/COMPARE Mode and initiate the count: 1. Write to the Timer Control 1 Register to: – Disable the timer – Configure the timer for CAPTURE/COMPARE Mode – Set the prescale value – Set the Capture edge (rising or falling) for the Timer Input 2. Write to the Timer High and Low Byte registers to set the starting count value (typically 0001h). 3. Write to the Timer Control 2 Register to choose the timer clock source. 4. Write to the Timer Control 0 Register to set the timer interrupt configuration field TICONFIG. 5. Write to the Timer Reload High and Low Byte registers to set the Compare value. 6. If required, enable the timer interrupt and set the timer-interrupt priority by writing to the relevant interrupt registers. By default, the timer interrupt will be generated for both input capture and reload events. If required, configure the timer interrupt to be generated only at the input Capture event or the Reload event by setting TICONFIG field of the Timer Control 0 Register. 7. Configure the associated GPIO port pin for the Timer Input alternate function. 8. Write to the Timer Control 1 Register to enable the timer. PS025016-1013 PRELIMINARY Timers Z8 Encore! XP® F1680 Series Product Specification 103 9. Counting begins on the first transition of the Timer Input signal. No interrupt is generated by this first edge. In CAPTURE/COMPARE Mode, the elapsed time from timer start to Capture event is calculated using the following equation:  Capture Value - Start Value   Prescale Capture Elapsed Time (s) = -------------------------------------------------------------------------------------------------Timer Clock Frequency (Hz) 9.2.3.13. DEMODULATION Mode In DEMODULATION Mode, the timer begins counting on the first external Timer Input transition. The appropriate transition (rising edge or falling edge or both) is set by the TPOL bit in the Timer Control 1 Register and TPOLHI bit in the Timer Control 2 Register. The Timer counts timer clocks up to the 16-bit reload value. Every subsequent appropriate transition (after the first) of the Timer Input signal captures the current count value. The Capture value is written to the Timer PWM0 High and Low Byte registers for rising input edges of the timer input signal. For falling edges the capture count value is written to the Timer PWM1 High and Low Byte registers. The TPOL bit in the Timer Control 1 Register determines if the Capture occurs on a rising edge or a falling edge of the Timer Input signal. If the TPOLHI bit in the Timer Control 2 Register is set, a Capture is executed on both the rising and falling edges of the input signal. Whenever the Capture event occurs, an interrupt is generated and the timer continues counting. The corresponding event flag bit in the Timer Status Register, PWMxEF, is set to indicate that the timer interrupt is due to an input Capture event. The timer counts up to the 16-bit Compare value stored in the Timer Reload High and Low Byte registers. Upon reaching the reload value, the timer generates an interrupt, the count value in the Timer High and Low Byte registers is reset to 0001h, and counting resumes. The RTOEF event flag bit in the Timer Status Register is set to indicate that the timer interrupt is due to a Reload event. Software can use this bit to determine if a Reload occurred prior to a Capture. Observe the following steps to configure a timer for DEMODULATION Mode and initiate the count: 1. Write to the Timer Control 1 Register to: – Disable the timer PS025016-1013 PRELIMINARY Timers Z8 Encore! XP® F1680 Series Product Specification 104 – – – Configure the timer for DEMODULATION Mode. Setting the mode also involves writing to the TMODEHI bit in the TxCTL0 Register Set the prescale value Set the TPOL bit to set the Capture edge (rising or falling) for the Timer Input. This setting applies only if the TPOLHI bit in the TxCTL2 Register is not set 2. Write to the Timer Control 2 Register to: – Choose the timer clock source – Set the TPOLHI bit if the Capture is required on both edges of the input signal 3. Write to the Timer Control 0 Register to set the timer interrupt configuration field TICONFIG. 4. Write to the Timer High and Low Byte registers to set the starting count value (typically 0001h). 5. Write to the Timer Reload High and Low Byte registers to set the reload value. 6. Clear the Timer TxPWM0 and TxPWM1 High and Low Byte registers to 0000h. 7. If required, enable the noise filter and set the noise filter control by writing to the relevant bits in the Noise Filter Control Register. 8. If required, enable the timer interrupt and set the timer interrupt priority by writing to the relevant interrupt registers. By default, the timer interrupt will be generated for both input capture and reload events. If required, configure the timer interrupt to be generated only at the input Capture event or the Reload event by setting TICONFIG field of the Timer Control 0 Register. 9. Configure the associated GPIO port pin for the Timer Input alternate function. 10. Write to the Timer Control 1 Register to enable the timer. Counting will start on the occurrence of the first external input transition. In DEMODULATION Mode, the elapsed time from timer start to Capture event can be calculated using the following equation:  Capture Value - Start Value   Prescale Capture Elapsed Time (s) = -------------------------------------------------------------------------------------------------Timer Clock Frequency (Hz) PS025016-1013 PRELIMINARY Timers Z8 Encore! XP® F1680 Series Product Specification 105 Table 54 provides an example initialization sequence for configuring Timer 0 in DEMODULATION Mode and initiating operation. Table 54. DEMODULATION Mode Initialization Example Register Value Comment T0CTL0 C0h T0CTL1 04h T0CTL2 11h TMODE[3:0] = 1100B selects DEMODULATION Mode. TICONFIG[1:0] = 10B enables interrupt only on Capture events. CSC = 0 selects the Timer Input from the GPIO pin. PWMD[2:0] = 000B has no effect. INPCAP = 0 has no effect. TEN = 0 disables the timer. PRES[2:0] = 000B sets prescaler to divide by 1. TPOLHI,TPOL = 10 enables trigger and Capture on both rising and falling edges of Timer Input. TCLKS = 1 enables 32 kHz peripheral clock as timer clock source T0h 00h T0L 01h T0RH ABh T0RL CDh T0PWM0h 00h T0PWM0L 00h T0PWM1h 00h T0PWM1h 00h T0NFC C0h NFEN = 1 enables noise filter NFCTL = 100B enables 8-bit up/down counter PAADDR 02h Selects Port A Alternate Function control register. PACTL[1:0] 11B PACTL[0] enables Timer 0 Input alternate function. PACTL[1] enables Timer 0 Output alternate function. IRQ0ENH[5] 0B Disables the Timer 0 interrupt. IRQ0ENL[5] 0B T0CTL1 84h Timer starting value = 0001h. Timer reload value = ABCDh Initial PWM0 value = 0000h Initial PWM1 value = 0000h TEN = 1 enables the timer. All other bits remain in their appropriate settings. Notes: Notes: After receiving the input trigger (rising or falling edge), Timer 0 will: 1. Start counting on the timer clock. 2. Upon receiving a Timer 0 Input rising edge, save the Capture value in the T0PWM0 registers, generate an interrupt, and continue to count. 3. Upon receiving a Timer 0 Input falling edge, save the Capture value in the T0PWM1 registers, generate an interrupt, and continue to count. 4. After the timer count to ABCD clocks, set the reload event flag and reset the Timer count to the start value. PS025016-1013 PRELIMINARY Timers Z8 Encore! XP® F1680 Series Product Specification 106 9.2.4. Reading the Timer Count Values The current count value in the timers can be read while counting (enabled). This capability has no effect on timer operation. When the timer is enabled and the Timer High Byte register is read, the contents of the Timer Low Byte Register are placed in a holding register. A subsequent read from the Timer Low Byte Register returns the value in the holding register. This operation allows accurate reads of the full 16-bit timer count value while enabled. When the timers are not enabled, a read from the Timer Low Byte Register returns the actual value in the counter. 9.2.5. Timer Output Signal Operation The Timer Output is a GPIO port pin alternate function. Generally, the Timer Output is toggled every time the counter is reloaded. The complement of the Timer Output is only available in Dual PWM Mode. 9.2.6. Timer Noise Filter A Noise Filter circuit is included which filters noise on a Timer Input signal before the data is sampled by the block. The Noise Filter has the following features: • • Synchronizes the receive input data to the Timer Clock • NFCTL (Noise Filter Control) input selects the width of the up/down saturating counter digital filter. The available widths range from 4 bits to 11 bits • • The digital filter output has hysteresis • Available for operation in STOP Mode NFEN (Noise Filter Enable) input selects whether the Noise Filter is bypassed (NFEN=0) or included (NFEN=1) in the receive data path Provides an active Low saturated state output (FiltSatB) which is used as an indication of the presence of noise 9.2.7. Architecture Figure 12 displays how the Noise Filter is integrated with the Timer. PS025016-1013 PRELIMINARY Timers Z8 Encore! XP® F1680 Series Product Specification 107 Timer Clock TxIN TxIN NEF Timer GPIO Noise Filter NFEN, NFCTL TxOUT TxOUT Figure 12. Noise Filter System Block Diagram 9.2.7.1. Operation Figure 13 displays the operation of the Noise Filter with and without noise. The Noise Filter in this example is a 2-bit up/down counter which saturates at 00 and 11. A 2-bit counter is described for convenience; the operation of wider counters is similar. The output of the filter switches from 1 to 0 when the counter counts down from 01 to 00 and switches from 0 to 1 when the counter counts up from 10 to 11. The Noise Filter delays the receive data by three timer clock cycles. The NEF output signal is checked when the filtered TxIN input signal is sampled. The Timer samples the filtered TxIN input near the center of the bit time. The NEF signal must be sampled at the same time to detect whether there is noise near the center of the bit time. The presence of noise (NEF = 1 at the center of the bit time) does not mean that the sampled data is incorrect; rather, it is intended to be an indicator of the level of noise in the network. PS025016-1013 PRELIMINARY Timers Z8 Encore! XP® F1680 Series Product Specification 108 Timer Clock Input TxIN (ideal) Data Bit = 0 Data Bit = 1 Clean TxIN example Noise Filter 3 3 2 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 2 3 3 3 3 3 3 3 3 3 3 3 3 3 3 Up/Dn Cntr Noise Filter Output nominal filter delay Input TxIN (noisy) Data Bit = 0 Data Bit = 1 Noise Filter Up/Dn Cntr 3 3 2 1 0 0 0 0 0 0 1 2 1 0 0 0 0 0 1 0 1 2 3 3 3 3 2 3 3 3 3 3 3 3 Noise TxIN example Noise Filter Output NEF output Figure 13. Noise Filter Operation 9.3. Timer Control Register Definitions This section defines the features of the following Timer Control registers. Timer 0–2 High and Low Byte Registers: see page 109 Timer Reload High and Low Byte Registers: see page 109 Timer 0–2 PWM0 High and Low Byte Registers: see page 110 Timer 0–2 PWM1 High and Low Byte Registers: see page 111 Timer 0–2 Control Registers: see page 112 Timer 0–2 Status Registers: see page 118 Timer 0–2 Noise Filter Control Register: see page 119 PS025016-1013 PRELIMINARY Timers Z8 Encore! XP® F1680 Series Product Specification 109 9.3.1. Timer 0–2 High and Low Byte Registers The Timer 0–2 High and Low Byte (TxH and TxL) registers, shown in Tables 55 and 56, contain the current 16-bit timer count value. When the timer is enabled, a read from TxH causes the value in TxL to be stored in a temporary holding register. A read from TxL always returns this temporary register when the timers are enabled. When the timer is disabled, reading from the TxL reads the register directly. Writing to the Timer High and Low Byte registers when the timer is enabled is not recommended. There are no temporary holding registers available for write operations; therefore simultaneous 16-bit writes are not possible. If either the Timer High or Low Byte registers are written during counting, the 8-bit written value is placed in the counter (High or Low Byte) at the next clock edge. The counter continues counting from the new value. Table 55. Timer 0–2 High Byte Register (TxH) Bit 7 6 5 4 Field 2 1 0 TH Reset R/W 3 0 0 0 0 0 0 0 0 R/W R/W R/W R/W R/W R/W R/W R/W Address F00h, F08h, F10h Table 56. Timer 0–2 Low Byte Register (TxL) Bit 7 6 5 4 Field 2 1 0 TL Reset R/W 3 0 0 0 0 0 0 0 1 R/W R/W R/W R/W R/W R/W R/W R/W Address F01h, F09h, F11h Bit Description [7:0] TH, TL Timer High and Low Bytes These 2 bytes, {TH[7:0], TL[7:0]}, contain the current 16-bit timer count value. 9.3.2. Timer Reload High and Low Byte Registers The Timer 0–2 Reload High and Low Byte (TxRH and TxRL) registers, shown in Tables 57 and 58, store a 16-bit reload value, {TRH[7:0], TRL[7:0]}. Values written to the Timer Reload High Byte Register are stored in a temporary holding register. When a write to the Timer Reload Low Byte Register occurs, this temporary holding register value is written to the Timer High Byte Register. This operation allows simultaneous updates of the 16-bit timer reload value. PS025016-1013 PRELIMINARY Timers Z8 Encore! XP® F1680 Series Product Specification 110 In COMPARE Mode, the Timer Reload High and Low Byte registers store the 16-bit Compare value. Table 57. Timer 0–2 Reload High Byte Register (TxRH) Bit 7 6 5 4 Field 2 1 0 TRH Reset R/W 3 1 1 1 1 1 1 1 1 R/W R/W R/W R/W R/W R/W R/W R/W Address F02h, F0Ah, F12h Table 58. Timer 0–2 Reload Low Byte Register (TxRL) Bit 7 6 5 4 Field 2 1 0 TRL Reset R/W 3 1 1 1 1 1 1 1 1 R/W R/W R/W R/W R/W R/W R/W R/W Address F03h, F0Bh, F13h Bit Description [7:0] TRH, TRL Timer Reload Register High and Low These two bytes form the 16-bit reload value, {TRH[7:0], TRL[7:0]}. This value is used to set the maximum count value which initiates a timer reload to 0001h. In COMPARE Mode, these two bytes form the 16-bit Compare value. 9.3.3. Timer 0–2 PWM0 High and Low Byte Registers The Timer 0–2 PWM0 High and Low Byte (TxPWM0h and TxPWM0L) registers, shown in Tables 59 and 60, are used for Pulse Width Modulator (PWM) operations. These registers also store the Capture values for the CAPTURE, CAPTURE/COMPARE and DEMODULATION Modes. When the timer is enabled, writes to these registers are buffered, and loading of the registers is delayed until a timer reload to 0001h occurs – that is, unless PWM0UE = 1. Table 59. Timer 0–2 PWM0 High Byte Register (TxPWM0h) Bit 7 6 5 4 Field 2 1 0 PWM0h Reset R/W 3 0 0 0 0 0 0 0 0 R/W R/W R/W R/W R/W R/W R/W R/W Address PS025016-1013 F04h, F0Ch, F14h PRELIMINARY Timers Z8 Encore! XP® F1680 Series Product Specification 111 Table 60. Timer 0–2 PWM0 Low Byte Register (TxPWM0L) Bit 7 6 5 4 Field 1 0 0 0 0 0 0 0 0 0 R/W R/W R/W R/W R/W R/W R/W R/W Address Bit 2 PWM0L Reset R/W 3 F05h, F0Dh, F15h Description [7:0] Pulse Width Modulator 0 High and Low Bytes PWM0h, These two bytes, {PWM0h[7:0], PWM0L[7:0]}, form a 16-bit value that is compared to the PWM0L current 16-bit timer count. When a match occurs, the PWM output changes state. The PWM output value is set by the TPOL bit in the Timer Control 1 Register (TxCTL1). The TxPWM0h and TxPWM0L registers also store the 16-bit captured timer value when operating in CAPTURE, CAPTURE/COMPARE and DEMODULATION Modes. 9.3.4. Timer 0–2 PWM1 High and Low Byte Registers The Timer 0–2 PWM1 High and Low Byte (TxPWM1h and TxPWM1L) registers, shown in Tables 61 and 62, store Capture values for DEMODULATION Mode. Table 61. Timer 0-2 PWM1 High Byte Register (TxPWM1h) Bit 7 6 5 4 Field 2 1 0 PWM1h Reset R/W 3 0 0 0 0 0 0 0 0 R/W R/W R/W R/W R/W R/W R/W R/W Address F20h, F24h, F28h Table 62. Timer 0–2 PWM1 Low Byte Register (TxPWM1L) Bit 7 6 5 4 Field 1 0 0 0 0 0 0 0 0 0 R/W R/W R/W R/W R/W R/W R/W R/W Address Bit 2 PWM1L Reset R/W 3 F21h, F25h, F29h Description [7:0] Pulse Width Modulator 1 High and Low Bytes PWM1h, These two bytes, {PWM1h[7:0], PWM1L[7:0]}, store the 16-bit captured timer value for PWM1L DEMODULATION Mode. PS025016-1013 PRELIMINARY Timers Z8 Encore! XP® F1680 Series Product Specification 112 9.3.5. Timer 0–2 Control Registers The Timer Control registers are described in Tables 63 through 65. 9.3.5.1. Timer 0–2 Control 0 Register The Timer 0–2 Control 0 (TxCTL0) register together with TxCTL1 register determines the timer operating mode. It also includes a programmable PWM deadband delay, two bits to configure timer interrupt definition and a status bit to identify if the last timer interrupt is due to an input capture event. Table 63. Timer 0–2 Control 0 Register (TxCTL0) Bit 7 6 5 3 1 PWMD 0 TMODE[3] Reset 0 0 0 0 0 0 0 0 R/W R/W R/W R/W R/W R/W R/W R/W Address CSC 2 Field R/W TICONFIG 4 INPCAP F06h, F0Eh, F16h Bit Description [7] TMODE[3] Timer Mode High Bit This bit, along with the TMODE[2:0] field in the TxCTL1 Register, determines the operating mode of the timer. This bit is the most significant bit of the timer mode selection value. For more details, see the description of the Timer 0–2 Control 1 Register (TxCTL1) on page 113. [6:5] TICONFIG Timer Interrupt Configuration This field configures timer interrupt definition. 0x = Timer Interrupt occurs on all defined Reload, Compare and Input Events. 10 = Timer Interrupt only on defined Input Capture/Deassertion Events. 11 = Timer Interrupt only on defined Reload/Compare Events. [4] CSC Cascade Timers 0 = Timer Input signal comes from the pin. 1 = For Timer 0, Input signal is connected to Timer 2 output. For Timer 1, Input signal is connected to Timer 0 output. For Timer 2, Input signal is connected to Timer 1 output. PS025016-1013 PRELIMINARY Timers Z8 Encore! XP® F1680 Series Product Specification 113 Bit Description (Continued) [3:1] PWMD PWM Delay Value This field is a programmable delay to control the number of timer clock cycles time delay before the Timer Output and the Timer Output Complement is forced to their active state. 000 = No delay 001 = 2 cycles delay 010 = 4 cycles delay 011 = 8 cycles delay 100 = 16 cycles delay 101 = 32 cycles delay 110 = 64 cycles delay 111 = 128 cycles delay [0] INPCAP Input Capture Event This bit indicates if the last timer interrupt is due to a Timer Input Capture Event. 0 = Previous timer interrupt is not a result of Timer Input Capture Event. 1 = Previous timer interrupt is a result of Timer Input Capture Event. 9.3.5.2. Timer 0–2 Control 1 Register The Timer 0–2 Control 1 (TxCTL1) registers enable and disable the timers, set the prescaler value and determine the timer operating mode. See Table 64. Table 64. Timer 0–2 Control 1 Register (TxCTL1) Bit 7 6 Field TEN TPOL Reset 0 0 0 0 0 0 0 0 R/W R/W R/W R/W R/W R/W R/W R/W R/W 5 4 3 2 PRES Address 1 0 TMODE F07h, F0Fh, F17h Bit Description [7] TEN Timer Enable 0 = Timer is disabled. 1 = Timer enabled to count. PS025016-1013 PRELIMINARY Timers Z8 Encore! XP® F1680 Series Product Specification 114 Bit Description (Continued) [6] TPOL Timer Input/Output Polarity Operation of this field is a function of the current operating modes of the timer. ONE-SHOT Mode When the timer is disabled, the Timer Output signal is set to the value of this bit. When the timer is enabled, the Timer Output signal is complemented upon timer reload. CONTINUOUS Mode When the timer is disabled, the Timer Output signal is set to the value of this bit. When the timer is enabled, the Timer Output signal is complemented upon timer reload. COUNTER Mode When the timer is disabled, the Timer Output signal is set to the value of this bit. When the timer is enabled, the Timer Output signal is complemented upon timer reload. 0 = Count occurs on the rising edge of the Timer Input signal. 1 = Count occurs on the falling edge of the Timer Input signal. PWM SINGLE OUTPUT Mode 0 = Timer Output is forced Low (0) when the timer is disabled. When enabled, the Timer Output is forced High (1) on PWM count match and forced Low (0) on Reload. 1 = Timer Output is forced High (1) when the timer is disabled. When enabled, the Timer Output is forced Low (0) on PWM count match and forced High (1) on Reload. CAPTURE Mode 0 = Count is captured on the rising edge of the Timer Input signal. 1 = Count is captured on the falling edge of the Timer Input signal. COMPARE Mode When the timer is disabled, the Timer Output signal is set to the value of this bit. When the timer is enabled, the Timer Output signal is complemented on timer reload. GATED Mode 0 = Timer counts when the Timer Input signal is High (1) and interrupts are generated on the falling edge of the Timer Input. 1 = Timer counts when the Timer Input signal is Low (0) and interrupts are generated on the rising edge of the Timer Input. CAPTURE/COMPARE Mode 0 = Counting is started on the first rising edge of the Timer Input signal. The current count is captured on subsequent rising edges of the Timer Input signal. 1 = Counting is started on the first falling edge of the Timer Input signal. The current count is captured on subsequent falling edges of the Timer Input signal. PS025016-1013 PRELIMINARY Timers Z8 Encore! XP® F1680 Series Product Specification 115 Bit Description (Continued) [6] (cont’d) PWM DUAL OUTPUT Mode 0 = Timer Output is forced Low (0) and Timer Output Complement is forced High (1) when the timer is disabled. When enabled, the Timer Output is forced High (1) upon PWM count match and forced Low (0) upon Reload. When enabled, the Timer Output Complement is forced Low (0) upon PWM count match and forced High (1) upon Reload. The PWMD field in Timer Control 0 Register is a programmable delay to control the number of cycles time delay before the Timer Output and the Timer Output Complement is forced to High (1). 1 = Timer Output is forced High (1) and Timer Output Complement is forced Low (0) when the timer is disabled. When enabled, the Timer Output is forced Low (0) upon PWM count match and forced High (1) upon Reload. When enabled, the Timer Output Complement is forced High (1) upon PWM count match and forced Low (0) upon Reload. The PWMD field in Timer Control 0 Register is a programmable delay to control the number of cycles time delay before the Timer Output and the Timer Output Complement is forced to Low (0). CAPTURE RESTART Mode 0 = Count is captured on the rising edge of the Timer Input signal. 1 = Count is captured on the falling edge of the Timer Input signal. COMPARATOR COUNTER Mode When the timer is disabled, the Timer Output signal is set to the value of this bit. When the timer is enabled, the Timer Output signal is complemented upon timer reload. TRIGGERED ONE-SHOT Mode 0 = Timer counting is triggered on the rising edge of the Timer Input signal. 1 = Timer counting is triggered on the falling edge of the Timer Input signal. DEMODULATION Mode 0 = Timer counting is triggered on the rising edge of the Timer Input signal. The current count is captured into PWM0 High and Low byte registers on subsequent rising edges of the Timer Input signal. 1 = Timer counting is triggered on the falling edge of the Timer Input signal. The current count is captured into PWM1 High and Low byte registers on subsequent falling edges of the Timer Input signal. The above functionality applies only if TPOLHI bit in Timer Control 2 Register is 0. If TPOLHI bit is 1 then timer counting is triggered on any edge of the Timer Input signal and the current count is captured on both edges. The current count is captured into PWM0 registers on rising edges and PWM1 registers on falling edges of the Timer Input signal. PS025016-1013 PRELIMINARY Timers Z8 Encore! XP® F1680 Series Product Specification 116 Bit Description (Continued) [5:3] PRES Prescale Value The timer input clock is divided by 2PRES, where PRES can be set from 0 to 7. The prescaler is reset each time the Timer is disabled. This insures proper clock division each time the Timer is restarted. 000 = Divide by 1 001 = Divide by 2 010 = Divide by 4 011 = Divide by 8 100 = Divide by 16 101 = Divide by 32 110 = Divide by 64 111 = Divide by 128 [2:0] Timer Mode TMODE[2:0] This field, along with the TMODE[3] bit in the TxCTL0 Register, determines the operating mode of the timer. TMODE[3:0] selects among the following modes: 0000 = ONE-SHOT Mode 0001 = CONTINUOUS Mode 0010 = COUNTER Mode 0011 = PWM SINGLE OUTPUT Mode 0100 = CAPTURE Mode 0101 = COMPARE Mode 0110 = GATED Mode 0111 = CAPTURE/COMPARE Mode 1000 = PWM DUAL OUTPUT Mode 1001 = CAPTURE RESTART Mode 1010 = COMPARATOR COUNTER Mode 1011 = TRIGGERED ONE-SHOT Mode 1100 = DEMODULATION Mode PS025016-1013 PRELIMINARY Timers Z8 Encore! XP® F1680 Series Product Specification 117 9.3.5.3. Timer 0–2 Control 2 Register The Timer 0–2 Control 2 (TxCTL2) registers allow selection of timer clock source and control of timer input polarity in DEMODULATION Mode. See Table 65. Table 65. Timer 0–2 Control 2 Register (TxCTL2) Bit 7 Field Reserved Reset R/W 6 5 4 PWM0UE TPOLHI 3 2 1 Reserved 0 TCLKS* 0 0 0 0 0 0 0 0 R/W R/W R/W R/W R/W R/W R/W R/W Address F22h, F26h, F2Ah Bit Description [7:6] Reserved; must be 0. [5] PWM0 Update Enable PWM0UE This bit determines whether writes to the PWM0 High and Low Byte registers are buffered when TEN = 1. Writes to these registers are not buffered when TEN = 0, regardless of the value of this bit. 0 = Writes to the Channel High and Low Byte registers are buffered when TEN = 1 and only take affect on a timer reload to 0001h. 1 = Writes to the Channel High and Low Byte registers are not buffered when TEN = 1. [4] TPOLHI Timer Input/Output Polarity High Bit This bit determines if timer count is triggered and captured on both edges of the input signal. This applies only to DEMODULATION Mode. 0 = Count is captured only on one edge in DEMODULATION Mode. In this case, edge polarity is determined by TPOL bit in the TxCTL1 Register. 1 = Count is triggered on any edge and captured on both rising and falling edges of the Timer Input signal in DEMODULATION Mode. [3:1] Reserved; must be 0. [0] TCLKS Timer Clock Source 0 = System Clock. 1 = Peripheral Clock.* Note: *Before selecting the peripheral clock as the timer clock source, the peripheral clock must be enabled and oscillating. PS025016-1013 PRELIMINARY Timers Z8 Encore! XP® F1680 Series Product Specification 118 9.3.6. Timer 0–2 Status Registers The Timer 0–2 Status (TxSTAT) indicates PWM capture/compare event occurrence, overrun errors, noise event occurrence and reload time-out status. Table 66. Timer 0–2 Status Register (TxSTAT) Bit 7 6 5 4 1 0 NEF Reset 0 0 0 0 0 0 0 0 R/W R/W R/W R/W R/W R/W R/W R/W Address RTOEF 2 Field R/W Reserved PWM1EO PWM0EO 3 Reserved PWM1EF PWM0EF F23h, F27h, F2Bh Bit Description [7] NEF Noise Event Flag This status is applicable only if the Timer Noise Filter is enabled. The NEF bit will be asserted if digital noise is detected on the Timer input (TxIN) line when the data is being sampled (center of bit time). If this bit is set, it does not mean that the timer input data is corrupted (though it can be in extreme cases), just that one or more Noise Filter data samples near the center of the bit time did not match the average data value. [6] Reserved; must be 0. [5:4] PWM x Event Overrun PWMxEO This bit indicates that an overrun error has occurred. An overrun occurs when a new capture/ compare event occurs before the previous PWMxEF bit is cleared. Clearing the associated PWMxEF bit in the TxSTAT register clears this bit. 0 = No Overrun 1 = Capture/Compare Event Flag Overrun [3] RTOEF Reload Time-Out Event Flag This flag is set if timer counts up to the reload value and is reset to 0001h. Software can use this bit to determine if a reload occurred prior to a capture. It can also determine if timer interrupt is due to a reload event. 0 = No Reload Time-Out event occurred 1 = A Reload Time-Out event occurred [2] Reserved; must be 0. [1:0] PWM x Event Flag PWMxEF This bit indicates if a capture/compare event occurred for this PWM channel. Software can use this bit to determine the PWM channel responsible for generating the timer interrupt. This event flag is cleared by writing a 1 to the bit. These bits will be set when an event occurs independent of the setting of the timer interrupt enable bit. 0 = No Capture/Compare Event occurred for this PWM channel 1 = A Capture/Compare Event occurred for this PWM channel PS025016-1013 PRELIMINARY Timers Z8 Encore! XP® F1680 Series Product Specification 119 9.3.7. Timer 0–2 Noise Filter Control Register The Timer 0–2 Noise Filter Control Register (TxNFC) enables and disables the Timer Noise Filter and sets the noise filter control. Table 67. Timer 0–2 Noise Filter Control Register (TxNFC) Bit 7 Field NFEN Reset 0 R/W 6 5 4 3 2 NFCTL 0 R/W Address 0 1 0 0 0 Reserved 0 0 R/W 0 R F2Ch, F2Dh, F2Eh Bit Description [7] NFEN Noise Filter Enable 0 = Noise Filter is disabled. 1 = Noise Filter is enabled. Receive data is preprocessed by the noise filter. [6:4] NFCTL Noise Filter Control This field controls the delay and noise rejection characteristics of the Noise Filter. The wider the counter the more delay that is introduced by the filter and the wider the noise event that will be filtered. 000 = 2-bit up/down counter 001 = 3-bit up/down counter 010 = 4-bit up/down counter 011 = 5-bit up/down counter 100 = 6-bit up/down counter 101 = 7-bit up/down counter 110 = 8-bit up/down counter 111 = 9-bit up/down counter [3:0] Reserved; must be 0. PS025016-1013 PRELIMINARY Timers Z8 Encore! XP® F1680 Series Product Specification 120 Chapter 10. Multi-Channel Timer The Multi-Channel timer, offered on all 44-pin F1680 Series parts, features a 16-bit up/ down counter and a 4-channel Capture/Compare/PWM channel array. This timer enables the support of multiple synchronous Capture/Compare/PWM channels based on a single timer. The Multi-Channel Timer also includes the following features: • • • • • 16-bit up/down timer counter with programmable prescale Selectable clock source (system clock or external input pin) Count Modulo and Count up/down COUNTER Modes Four independent capture/compare channels which reference the common timer Channel modes: – ONE-SHOT COMPARE Mode – CONTINUOUS COMPARE Mode – PWM OUTPUT COMPARE Mode – CAPTURE Mode 10.1. Architecture Figure 14 displays the Multi-Channel Timer architecture. PS025016-1013 PRELIMINARY Multi-Channel Timer Z8 Encore! XP® F1680 Series Product Specification 121 Data Bus Timer and Channel Control Block Control 16-Bit Reload Register System Clock 16-Bit Counter with Prescaler Timer Input (TIN) A Timer Channel B C Inputs D (T4CHA – T4CHD) Gate Input Four16-Bit PWM Capture Compare Channels C O M P A R E C O M P A R E Interrupt, PWM, and Timer Output Control Timer Interrupt A B Timer Channel Outputs C D (T4CHA – T4CHD) Figure 14. Multi-Channel Timer Block Diagram 10.2. Timer Operation This section discusses the key features of the Multi-Channel Timer, including its counter, clock source, prescaler and counting modes. 10.2.1. Multi-Channel Timer Counter The Multi-Channel Timer is based around a 16-bit up/down counter. The counter, depending on the TIMER mode counts up or down with each rising edge of the clock signal. Timer Counter registers MCTH and MCTL can be read/written by software. 10.2.2. Clock Source The Multi-Channel Timer clock source can come from either the system clock or the alternate function TIN pin when the system clock is the clock source; the alternate function TIN input pin can perform a clock gating function. The TCLKS field in the MCTCTL0 Register selects the timer clock source. When using the TIN pin, the associated GPIO pin, T4CH, must be configured as an input. The TIN frequency cannot exceed one-fourth the system clock frequency. PS025016-1013 PRELIMINARY Multi-Channel Timer Z8 Encore! XP® F1680 Series Product Specification 122 10.2.3. Multi-Channel Timer Clock Prescaler The prescaler allows the system clock signal to be decreased by factors of 1, 2, 4, 8, 16, 32, 64 or 128. The PRES[2:0] bit field in the MCTCTL1 Register controls prescaler operation. The PRES field is buffered for the prescale value to change only on a MultiChannel Timer end-of-cycle count. The prescaler has no effect when the TIN is selected as the clock source. 10.2.4. Multi-Channel Timer Start The Multi-Channel Timer starts counting when the TEN bit in the MCTCTL1 Register is set and the clock source is active. In Count Modulo or Count Up/Down mode, the timer counting can be stopped without disabling the timer by setting the Reload Register to 0. The timer will then stop when the counter next reaches 0. Writing a nonzero value to the Reload Register restarts the timer counting. 10.2.5. Multi-Channel Timer Mode Control The Multi-Channel Timer supports two modes of operation: Count Modulo and Count up/ down. The operating mode is selected with the TMODE[1:0] field in the MCTCTL1 Register. The timer modes are described below in Table 68. Table 68. Timer Count Modes TMODE Timer Mode Description 00 Count Modulo Timer counts up to Reload Register value. Then it is reset to 0000h and counting resumes. 01 Reserved 10 Count Up/Down 11 Reserved Timer counts up to Reload and then counts down to 0000h. The Count up/ down cycle continues. 10.2.6. Count Modulo Mode In the Count Modulo Mode, the Timer counts up to the Reload Register value (max value = FFFFh). Then it is reset to 0000h and counting resumes. As shown in Figure 15, the counting cycle continues with Reload + 1 as the period. A timer count interrupt request is generated when the timer count resets from Reload to 0000h. If Count Modulo is selected when the timer count is greater than Reload, the timer immediately restarts counting from zero. PS025016-1013 PRELIMINARY Multi-Channel Timer Z8 Encore! XP® F1680 Series Product Specification 123 FFFFh Reload 0h Figure 15. Count Modulo Mode 10.2.7. Count Up/Down Mode In the Count Up/Down mode, the timer counts up to the Reload Register value and then counts down to 0000h. As shown in Figures 16, the counting cycle continues with twice the reload value as the period. A timer count interrupt is generated when the timer count decrements to zero. Reload 0h Figure 16. Count Up/Down Mode PS025016-1013 PRELIMINARY Multi-Channel Timer Z8 Encore! XP® F1680 Series Product Specification 124 10.3. Capture/Compare Channel Operation The Multi-Channel timer supports four Capture/Compare channels: CHA, CHB, CHC and CHD. Each channel has the following features: • A 16-bit Capture/Compare Register (MCTCHyH and MCTCHyL registers) used to capture input event times or to generate time intervals. Any user software update of the Capture/Compare Register value when the timer is running takes effect only at the end of the counting cycle, not immediately. The end of the counting cycle is when the counter transitions from the reload value to 0 (count modulo mode) or from 1 to 0 (count up/ down mode). • A dedicated bidirectional pin (T4CHA, T4CHB, T4CHC, or T4CHD) that can be configured for the input capture function or to generate an output compare match or oneshot pulse. Each channel is configured to operate in ONE-SHOT COMPARE, CONTINUOUS COMPARE, PWM OUTPUT, or INPUT CAPTURE mode. 10.3.1. One-Shot Compare Operation In a ONE-SHOT COMPARE operation, a channel interrupt is generated when the channel compare value matches the timer count. The channel event flag (CHyEF) is set in the Channel Status 1 Register (MCTCHS1) to identify the responsible channel. The channel is then automatically disabled. The timer continues counting according to the programmed mode. If the timer channel output alternate function is enabled, the channel output pin (T4CHA, T4CHB, T4CHC, or T4CHD) changes state for one system clock cycle upon match (i.e., from Low to High, then back to Low or High to Low, then back to High as determined by the CHPOL bit). 10.3.2. Continuous Compare Operation In a CONTINUOUS COMPARE operation, a channel interrupt is generated when the channel compare value matches the timer count. The channel event flag (CHyEF) is set in the Channel Status 1 Register (MCTCHS1) and the channel remains enabled. The timer continues counting according to the programmed mode. If the channel output alternate function is enabled, the channel output pin (T4CHA, T4CHB, T4CHC, or T4CHD) changes state upon match (i.e., from Low to High then back to Low; or High to Low then back to High, as determined by the CHPOL bit). PS025016-1013 PRELIMINARY Multi-Channel Timer Z8 Encore! XP® F1680 Series Product Specification 125 10.3.3. PWM Output Operation In a PWM OUTPUT operation, the timer generates a PWM output signal on the channel output pin (T4CHA, T4CHB, T4CHC, or T4CHD). The channel output toggles whenever the timer count matches the channel compare value (defined in the MCTCHyH and MCTCHyL registers). In addition, a channel interrupt is generated and the channel event flag is set in the status register. The timer continues counting according to its programmed mode. The channel output signal begins with the output value = CHPOL and then transitions to CHPOL when timer value matches the PWM value. If timer mode is Count Modulo, the channel output signal returns to output = CHPOL when timer reaches the reload value and is reset. If timer mode is Count up/down, channel output signal returns to output = CHPOL when the timer count matches the PWM value again (when counting down). 10.3.4. Capture Operation In a CAPTURE operation, the current timer count is recorded when the selected transition occurs on T4CHA, T4CHB, T4CHC or T4CHD. The Capture count value is written to the Channel High and Low Byte registers. In addition, a channel interrupt is generated and the channel event flag (CHyEF) is set in the Channel Status Register. The CHPOL bit in the Channel Control Register determines if the Capture occurs on a rising edge or a falling edge of the Channel Input signal. The timer continues counting according to the programmed mode. 10.4. Multi-Channel Timer Interrupts The Multi-Channel Timer provides a single interrupt which has five possible sources. These sources are the internal timer and the four channel inputs (T4CHA, T4CHB, T4CHC, T4CHD). 10.4.1. Timer Interrupt If enabled by the TCIEN bit of the MCTCTL0 Register, the timer interrupt will be generated when the timer completes a count cycle. This occurs during transition from counter = reload register value to counter = 0 in count modulo mode and occurs during transition from counter = 1 to counter = 0 in count up/down mode. 10.4.2. Capture/Compare Channel Interrupt A channel interrupt is generated whenever there is a successful Capture/Compare Event on the Timer Channel and the associated CHIEN bit is set. PS025016-1013 PRELIMINARY Multi-Channel Timer Z8 Encore! XP® F1680 Series Product Specification 126 10.5. Low-Power Modes The Z8 Encore! XP F1680 Series of MCUs contains power-saving features. The highest level of power reduction is provided by STOP Mode. The next level of power reduction is provided by HALT Mode. 10.5.1. Operation in HALT Mode When the eZ8 CPU is operating in HALT Mode, the Multi-Channel Timer will continue to operate if enabled. To minimize current in HALT Mode, the Multi-Channel Timer must be disabled by clearing the TEN control bit. 10.5.2. Operation in STOP Mode When the eZ8 CPU is operating in STOP Mode, the Multi-Channel Timer ceases to operate because the system clock has stopped. The registers are not reset and operation will resume after Stop Mode Recovery occurs. 10.5.3. Power Reduction During Operation Deassertion of the TEN bit will inhibit clocking of the entire Multi-Channel Timer block. Deassertion of the CHEN bit of individual channels will inhibit clocking of channelspecific logic to minimize power consumption of unused channels. The CPU can still read and write to the registers when the enable bit(s) are deasserted. 10.6. Multi-Channel Timer Applications Examples This section provides two brief examples that describe how the the F1680 Series multichannel timer can be used in your application. 10.6.1. PWM Programmable Deadband Generation The count up/down mode supports motor control applications that require dead time between output signals. Figure 17 displays dead time generation between two channels operating in count up/down mode. PS025016-1013 PRELIMINARY Multi-Channel Timer Z8 Encore! XP® F1680 Series Product Specification 127 FFFFh Reload MCTCH0 MCTCH1 0h Dead Time TCH0 Output TCH1 Output CI CI CI CI CI TI CI CI CI Channel Interrupts (CI) TI Timer Interrupts (TI) Figure 17. Count Up/Down Mode with PWM Channel Outputs and Deadband 10.6.2. Multiple Timer Intervals Generation Figure 18 shows a timing diagram featuring two constant time intervals, T0 and T1. The timer is in Count Modulo Mode with reload = FFFFh. Channels 0 and 1 are set up for CONTINUOUS COMPARE operation. After every channel compare interrupt, the channel Capture/Compare registers are updated in the interrupt service routine by adding a constant equal to the time interval required. This operation requires that the Channel Update Enable (CHUE) bit must be set in channels 0 and 1 so that writes to the Capture/ Compare registers take affect immediately. PS025016-1013 PRELIMINARY Multi-Channel Timer Z8 Encore! XP® F1680 Series Product Specification 128 FFFFh 0h t0 t0 t0 t1 t1 t0 t1 Figure 18. Count Max Mode with Channel Compare 10.7. Multi-Channel Timer Control Register Definitions This section defines the features of the following Multi-Channel Timer Control registers. Multi-Channel Timer High and Low Byte Registers: see page 130 Multi-Channel Timer Reload High and Low Byte Registers: see page 130 Multi-Channel Timer Subaddress Register: see page 131 Multi-Channel Timer Subregister x (0, 1, or 2): see page 132 Multi-Channel Timer Control 0, Control 1 Registers: see page 132 Multi-Channel Timer Channel Status 0 and Status 1 Registers: see page 135 Multi-Channel Timer Channel-y Control Registers: see page 137 Multi-Channel Timer Channel-y High and Low Byte Registers: see page 139 10.7.1. Multi-Channel Timer Address Map Table 69 defines the byte address offsets for the Multi-channel Timer registers. For saving address space, a subaddress is used for the Timer Control 0, Timer Control 1, Channel Status 0, Channel Status 1, Channel-y Control, and Channel-y High and Low byte registers. Only the Timer High and Low Byte registers and the Reload High and Low Byte registers can be directly accessed. PS025016-1013 PRELIMINARY Multi-Channel Timer Z8 Encore! XP® F1680 Series Product Specification 129 While writing a subregister, first write the subaddress to Timer Subaddress Register, then write data to subregister0, subregister1, or subregister2. A read is the same as a write. Table 69. Multi-Channel Timer Address Map Address/Subaddress Register/Subregister Name Direct Access Register FA0 Timer (Counter) High FA1 Timer (Counter) Low FA2 Timer Reload High FA3 Timer Reload Low FA4 Timer Subaddress FA5 Subregister 0 FA6 Subregister 1 FA7 Subregister 2 Subregister 0 0 Timer Control 0 1 Channel Status 0 2 Channel A Capture/Compare High 3 Channel B Capture/Compare High 4 Channel C Capture/Compare High 5 Channel D Capture/Compare High Subregister 1 0 Timer Control 1 1 Channel Status 1 2 Channel A Capture/Compare Low 3 Channel B Capture/Compare Low 4 Channel C Capture/Compare Low 5 Channel D Capture/Compare Low Subregister 2 PS025016-1013 0 Reserved 1 Reserved 2 Channel A Control 3 Channel B Control 4 Channel C Control 5 Channel D Control PRELIMINARY Multi-Channel Timer Z8 Encore! XP® F1680 Series Product Specification 130 10.7.2. Multi-Channel Timer High and Low Byte Registers The High and Low Byte (MCTH and MCTL) registers, shown in Table 70, contain the current 16-bit Multi-Channel Timer count value. Zilog does not recommend writing to the Multi-Channel Timer High and Low Byte registers while the Multi-Channel Timer is enabled. If either or both of the Multi-Channel Timer High or Low Byte registers are written during counting, the 8-bit written value is placed in the counter (High and/or Low byte) at the next system clock edge. The counter continues counting from the new value. Table 70. Multi-Channel Timer High and Low Byte Registers (MCTH, MCTL) Bit 7 6 5 4 Field 1 0 0 0 0 0 0 0 0 0 R/W R/W R/W R/W R/W R/W R/W R/W 3 2 1 0 Address FA0h Bit 7 6 5 4 Field MCTL Reset R/W 2 MCTH Reset R/W 3 0 0 0 0 0 0 0 0 R/W R/W R/W R/W R/W R/W R/W R/W Address FA1h Bit Description [7:0] MCTH, MCTL Multi-Channel Timer High and Low Byte These bytes contain the current 16-bit Multi-Channel Timer count value, {MCTH[7:0], MCTL[7:0]}. When the Multi-Channel Timer is enabled, a read from MCTH causes the value in MCTL to be stored in a temporary holding register. A read from MCTL returns this temporary register when the Multi-Channel Timer is enabled. When the Multi-Channel Timer is disabled, reads from MCTL read the register directory. The Multi-Channel Timer High and Low Byte registers are not reset when TEN = 0. 10.7.3. Multi-Channel Timer Reload High and Low Byte Registers The Multi-Channel Timer Reload High and Low Byte (MCTRH and MCTRL) registerss, shown in Table 71, store a 16-bit reload value, {MCTRH[7:0], MCTRL[7:0]}. When TEN = 0, writes to this address update the register on the next clock cycle. When TEN = 1, PS025016-1013 PRELIMINARY Multi-Channel Timer Z8 Encore! XP® F1680 Series Product Specification 131 writes to this register are buffered and transferred into the register when the counter reaches the end of the count cycle. Prescaler   Reload Value + 1  Modulo Mode Period = ---------------------------------------------------------------------------------------f MCTclk 2  Prescaler  Reload Value Up  Down Mode Period = ----------------------------------------------------------------------------------f MCTclk Table 71. Multi-Channel Timer Reload High and Low Byte Registers (MCTRH, MCTRL) Bit 7 6 5 4 Field 0 1 1 1 1 1 1 1 R/W R/W R/W R/W R/W R/W R/W R/W 3 2 1 0 FA2h Bit 7 6 5 4 Field MCTRL Reset 1 1 1 1 1 1 1 1 R/W R/W R/W R/W R/W R/W R/W R/W Address Bit 1 1 Address R/W 2 MCTRH Reset R/W 3 FA3h Description [7:0] Multi-Channel Timer Reload Register High and Low MCTRH, These two bytes form the 16-bit reload value, {MCTRH[7:0], MCTRL[7:0]}. This value sets the MCTRL Multi-Channel Timer period in Modulo and Up/Down Count modes. The value written to the MCTRH is stored in a temporary holding register. When a write to the MCTRL occurs, the temporary holding register value is written to the MCTRH. This operation allows simultaneous updates of the 16-bit Multi-Channel Timer reload value. 10.7.4. Multi-Channel Timer Subaddress Register The Multi-Channel Timer Subaddress Register stores 3-bit subaddresses for subregisters. These three bits are from MCTSAR[2:0], all other bits are reserved. When accessing subregister (writing or reading), set MCTSA right value first, then access subregister by writing or reading Subregisters 0, 1, or 2. PS025016-1013 PRELIMINARY Multi-Channel Timer Z8 Encore! XP® F1680 Series Product Specification 132 Table 72. Multi-Channel Timer Subaddress Register (MCTSA) Bit 7 6 5 4 Field 2 1 0 MCTSA Reset R/W 3 X X X X X X X X R/W R/W R/W R/W R/W R/W R/W R/W Address FA4h 10.7.5. Multi-Channel Timer Subregister x (0, 1, or 2) The Multi-Channel Timer subregisters 0, 1 or 2 store the 8-bit data write to subregister or 8-bit data read from subregister. The Multi-Channel Timer Subaddress Register selects the subregister to be written to or read from. Table 73. Multi-Channel Timer Subregister x (MCTSRx) Bit 7 6 5 4 Field 2 1 0 MCTSRx Reset R/W 3 X X X X X X X X R/W R/W R/W R/W R/W R/W R/W R/W Address FA5h, FA6h, FA7h 10.7.6. Multi-Channel Timer Control 0, Control 1 Registers The Multi-Channel Timer Control registers (MCTCTL0, MCTCTL1) control MultiChannel Timer operation. Writes to the PRES field of the MCTCTL1 Register are buffered when TEN = 1 and will not take effect until the next end of the cycle count occurs. Table 74. Multi-Channel Timer Control 0 Register (MCTCTL0) Bit 7 6 5 Field TCTST CHST TCIEN Reset 0 0 0 0 0 0 0 0 R/W R R/W R R R/W R/W R/W R/W Address 4 3 2 Reserved Reserved 1 0 TCLKS See note. Note: If a 00h is in the Subaddress Register, it is accessible through Subregister 0. PS025016-1013 PRELIMINARY Multi-Channel Timer Z8 Encore! XP® F1680 Series Product Specification 133 Bit Description [7] TCTST Timer Count Status This bit indicates if a timer count cycle is complete and is cleared by writing 1 to the bit and is cleared when TEN = 0. 0 = Timer count cycle is not complete. 1 = Timer count cycle is complete. [6] CHST Channel Status This bit indicates if a channel Capture/Compare event occurred. This bit is the logical OR of the CHyEF bits in the MCTCHS1 register. This bit is cleared when TEN=0. 0 = No channel capture/compare event has occurred. 1 = A channel capture/compare event has occurred. One or more of the CHDEF, CHCEF, CHBEF and CHAEF bits in the MCTCHS1 register are set. [5] TCIEN Timer Count Interrupt Enable This bit enables generation of timer count interrupt. A timer count interrupt is generated whenever the timer completes a count cycle: counting up to Reload Register value or counting down to zero depending on whether the TIMER mode is Count Modulo or Count up/down. 0 = Timer Count Interrupt is disabled. 1 = Timer Count Interrupt is enabled. [4:3] Reserved; must be 0. 2:0 TCLKS Timer Clock Source 000 = System Clock (Prescaling enabled) 001 = Reserved 010 = System Clock gated by active High Timer Input signal (Prescaling enabled). 011 = System Clock gated by active Low Timer Input signal (Prescaling enabled). 100 = Timer I/O pin input rising edge (Prescaler disabled). 101 = Timer I/O pin input falling edge (Prescaler disabled). 110 = Reserved. 111 = Reserved. Note: PS025016-1013 The input frequency of the Timer Input Signal must not exceed one-fourth the system clock frequency. PRELIMINARY Multi-Channel Timer Z8 Encore! XP® F1680 Series Product Specification 134 Table 75. Multi-Channel Timer Control 1 Register (MCTCTL1) Bit 7 6 Field TEN Reserved Reset 0 0 0 0 0 0 0 0 R/W R R/W R/W R/W R R/W R/W R/W Address 5 4 3 PRES 2 1 Reserved 0 TMODE See note. Note: If a 00h is in the Subaddress Register, it is accessible through Subregister 1. Bit Description [7] TEN Timer Enable 0 = Timer is disabled and the counter is reset. 1 = Timer is enabled to count. [6] Reserved; must be 0. [5:3] PRES Prescale Value The system clock is divided by 2PRES, where PRES can be set from 0 to 7. The prescaling operation is not applied when the alternate function input pin is selected as the timer clock source. 000 = Divide by 1 001 = Divide by 2 010 = Divide by 4 011 = Divide by 8 100 = Divide by 16 101 = Divide by 32 110 = Divide by 64 111 = Divide by 128 [2] Reserved; must be 0. [1:0] TMODE Timer Mode 00 = Count Modulo: Timer Counts up to Reload Register value. Then it is reset to 0000h and counting up resumes. 01 = Reserved. 10 = Count up/down: Timer Counts up to Reload and then counts down to 0000h. The count up and count down cycle continues. 11 = Reserved. PS025016-1013 PRELIMINARY Multi-Channel Timer Z8 Encore! XP® F1680 Series Product Specification 135 10.7.7. Multi-Channel Timer Channel Status 0 and Status 1 Registers The Multi-Channel Timer Channel Status 0 and Status 1 registers (MCTCHS0, MCTCHS1) indicate channel overruns and channel capture/compare events. Table 76. Multi-Channel Timer Channel Status 0 Register (MCTCHS0) Bit 7 6 Field 5 4 Reserved 3 2 1 0 CHDEO CHCEO CHBEO CHAEO Reset 0 0 0 0 0 0 0 0 R/W R R R R R R R R Address See note. Note: If a 01h is in the Subaddress Register, it is accessible through Subregister 0. Bit Description [7:4] Reserved; must be 0. [3:0] CHyEO Channel y Event Flag Overrun This bit indicates that an overrun error has occurred. An overrun occurs when a new Capture/ Compare event occurs before the previous CHyEF bit is cleared. Clearing the associated CHyEF bit in the MCTCHS1 register clears this bit. This bit is cleared when TEN=0 (TEN is the MSB of MCTCTL1). 0 = No Overrun. 1 = Capture/Compare Event Flag Overrun PS025016-1013 PRELIMINARY Multi-Channel Timer Z8 Encore! XP® F1680 Series Product Specification 136 Table 77. Multi-Channel Timer Channel Status 1 Register (MCTCHS1) Bit 7 6 Field 5 4 Reserved 3 2 1 0 CHDEF CHCEF CHBEF CHAEF Reset 0 0 0 0 0 0 0 0 R/W R R R R R/W R/W R/W R/W Address See note. Note: If a 01h is in the Subaddress Register, it is accessible through Subregister 1. Bit Description [7:4] Reserved; must be 0. [3:0] CHyEF Channel y Event Flag This bit indicates if a Capture/Compare event occurred for this channel. Software can use this bit to determine the channel(s) responsible for generating the Multi-Channel Timer channel interrupt. This event flag is cleared by writing a 1 to the bit. These bits will be set when an event occurs independent of the setting of the CHIEN bit. This bit is cleared when TEN=0 (TEN is the MSB of MCTCTL1). 0 = No Capture/Compare Event occurred for this channel. 1 = A Capture/Compare Event occurred for this channel. PS025016-1013 PRELIMINARY Multi-Channel Timer Z8 Encore! XP® F1680 Series Product Specification 137 10.7.8. Multi-Channel Timer Channel-y Control Registers Each channel has a control register to enable the channel, select the input/output polarity, enable channel interrupts and select the channel mode of operation. Table 78. Multi-Channel Timer Channel Control Register (MCTCHyCTL)1 Bit 7 6 5 4 3 Field CHEN CHPOL CHIEN CHUE Reserved Reset 0 0 0 0 0 0 0 0 R/W R/W R/W R/W R R/W R/W R/W R/W Address 2 1 0 CHOP See note 2. Notes: 1. y = A, B, C, D. 2. If 02h, 03h, 04h and 05h are in the Subaddress Register, they are accessible through Subregister 2. Bit Description [7] CHEN Channel Enable 0 = Channel is disabled. 1 = Channel is enabled. [6] CHPOL Channel Input/Output Polarity Operation of this bit is a function of the current operating method of the channel. ONE-SHOT Operation When the channel is disabled, the Channel Output signal is set to the value of this bit. When the channel is enabled, the Channel Output signal toggles for one system clock on reaching the Channel Capture/Compare Register value. CONTINUOUS COMPARE Operation When the channel is disabled, the Channel Output signal is set to the value of this bit. When the channel is enabled, the Channel Output signal toggles (from Low to High or High to Low) on reaching the Channel Capture/Compare Register value. PWM OUTPUT Operation 0 = Channel Output is forced Low when the channel is disabled. When enabled, the Channel Output is forced High on Channel Capture/Compare Register value match and forced Low on reaching the Timer Reload Register value (modulo mode) or counting down through the channel Capture/Compare register value (count up/down mode). 1 = Channel Output is forced Low when the channel is disabled. When enabled, the Channel Output is forced High on Channel Capture/Compare Register value match and forced Low on reaching the Timer Reload Register value (modulo mode) or counting down through the channel Capture/Compare register value (count up/down mode). CAPTURE Operation 0 = Count is captured on the rising edge of the Channel Input signal. 1 = Count is captured on the falling edge of the Channel Input signal. PS025016-1013 PRELIMINARY Multi-Channel Timer Z8 Encore! XP® F1680 Series Product Specification 138 Bit Description (Continued) [5] CHIEN Channel Interrupt Enable This bit enables generation of channel interrupt. A channel interrupt is generated whenever there is a capture/compare event on the Timer Channel. 0 = Channel interrupt is disabled. 1 = Channel interrupt is enabled. [4] CHUE Channel Update Enable This bit determines whether writes to the Channel High and Low Byte registers are buffered when TEN = 1. Writes to these registers are not buffered when TEN = 0 regardless of the value of this bit. 0 = Writes to the Channel High and Low Byte registers are buffered when TEN = 1 and only take affect on the next end of cycle count. 1 = Writes to the Channel High and Low Byte registers are not buffered when TEN = 1. [3] Reserved; must be 0. [2:0] CHOP Channel Operation Method This field determines the operating mode of the channel. For a detailed description of the operating modes, see Count Up/Down Mode on page 123. 000 = One-Shot Compare operation. 001 = Continuous Compare operation. 010 = PWM Output operation. 011 = Capture operation. 100 – 111 = Reserved. PS025016-1013 PRELIMINARY Multi-Channel Timer Z8 Encore! XP® F1680 Series Product Specification 139 10.7.9. Multi-Channel Timer Channel-y High and Low Byte Registers Each channel has a 16-bit capture/compare register defined here as the Channel-y High and Low Byte registers. When the timer is enabled, writes to these registers are buffered and loading of the registers is delayed until the next timer end count, unless CHUE = 1. Table 79. Multi-Channel Timer Channel-y High Byte Registers (MCTCHyH)* Bit 7 6 5 4 Field 2 1 0 CHyH Reset R/W 3 0 0 0 0 0 0 0 0 R/W R/W R/W R/W R/W R/W R/W R/W Address See note. Note: If 02h, 03h, 04h and 05h are in the Subaddress Register, they are accessible through Subregister 0. Bit 7 6 5 4 Field 2 1 0 CHyL Reset R/W 3 0 0 0 0 0 0 0 0 R/W R/W R/W R/W R/W R/W R/W R/W Address Note: If 02h, 03h, 04h and 05h are in the Subaddress Register, they are accessible through Subregister 1. Bit Description [7:0] CHyH, CHyL Multi-Channel Timer Channel-y High and Low Bytes During a compare operation, these two bytes, {CHyH[7:0], CHyL[7:0]}, form a 16-bit value that is compared to the current 16-bit timer count. When a match occurs, the Channel Output changes state. The Channel Output value is set by the TPOL bit in the Channel-y Control subregister. During a capture operation, the current Timer Count is recorded in these two bytes when the appropriate Channel Input transition occurs. Note: *y = A, B, C, D. PS025016-1013 PRELIMINARY Multi-Channel Timer Z8 Encore! XP® F1680 Series Product Specification 140 Chapter 11. Watchdog Timer The Watchdog Timer (WDT) function helps protect against corrupted or unreliable software and other system-level problems that can place the Z8 Encore! XP F1680 Series MCU into unsuitable operating states. The WDT includes the following features: • • • On-chip RC oscillator A selectable time-out response: Reset or System Exception 16-bit programmable time-out value 11.1. Operation The WDT is a retriggerable one-shot timer that resets or interrupts the Z8 Encore! XP F1680 Series when the WDT reaches its terminal count. The WDT uses its own dedicated on-chip RC oscillator as its clock source. The WDT has only two modes of operation— ON and OFF. After it is enabled, the WDT always counts and must be refreshed to prevent a time-out. An enable can be performed by executing the WDT instruction or by writing the WDT_AO option bit. When cleared to 0, the WDT_AO bit enables the WDT to operate continuously, even if a WDT instruction has not been executed. To minimize power consumption, the RC oscillator can be disabled. The RC oscillator is disabled by clearing the WDTEN bit in the Oscillator Control 0 Register (OSCCTL0)1. If the RC oscillator is disabled, the WDT will not operate. The WDT is a 16-bit reloadable downcounter that uses two 8-bit registers in the eZ8 CPU register space to set the reload value. The nominal WDT time-out period is calculated using the following equation: WDT Reload Value WDT Time– Out Period  ms  = ------------------------------------------------------10 In the above equation, the WDT reload value is computed using {WDTH[7:0], WDTL[7:0]} and the typical Watchdog Timer RC Oscillator frequency is 10 kHz. Users must consider system requirements when selecting the time-out delay. Table 80 indicates the approximate time-out delays for the default and maximum WDT reload values. 1. For details about this register, see Table 170 on page 319. PS025016-1013 PRELIMINARY Watchdog Timer Z8 Encore! XP® F1680 Series Product Specification 141 Table 80. Watchdog Timer Approximate Time-Out Delays Approximate Time-Out Delay (with 10 kHz Typical WDT Oscillator Frequency) WDT Reload Value (Hex) WDT Reload Value (Decimal) Typical Description 0400 1024 102 ms Reset default value time-out delay. FFFF 65,536 6.55 s Maximum time-out delay. 11.1.1. Watchdog Timer Refresh When first enabled, the WDT is loaded with the value in the WDT Reload registers. The WDT then counts down to 0000h unless a WDT instruction is executed by the eZ8 CPU. Execution of the WDT instruction causes the downcounter to be reloaded with the WDT reload value stored in the WDT Reload registers. Counting resumes following the reload operation. When the eZ8 CPU is operating in DEBUG Mode (through the OCD), the WDT is continuously refreshed to prevent unnecessary WDT time-outs. 11.1.2. Watchdog Timer Time-Out Response The WDT times out when the counter reaches 0000h. A time-out of the WDT generates either a system exception or a Reset. The WDT_RES option bit determines the time-out response of the WDT. For information about programming the WDT_RES option bit, see the Flash Option Bits section on page 276. 11.1.2.1. WDT System Exception in Normal Operation If it is configured to generate a system exception when a time-out occurs, the WDT issues an exception request to the interrupt controller. The eZ8 CPU responds to the request by fetching the System Exception vector and executing code from the vector address. After time-out and system exception generation, the WDT is reloaded automatically and continues counting. 11.1.2.2. WDT System Exception in STOP Mode The WDT automatically initiates a Stop Mode Recovery and generates a system exception request if configured to generate a system exception when a time-out occurs and the CPU is in STOP Mode. Both the WDT status bit and the stop bit in the Reset Status Register are set to 1 following a WDT time-out in STOP Mode. Upon completion of the Stop Mode Recovery, the eZ8 CPU responds to the system exception request by fetching the System Exception vector and executing code from the vector address. PS025016-1013 PRELIMINARY Watchdog Timer Z8 Encore! XP® F1680 Series Product Specification 142 11.1.2.3. WDT Reset in Normal Operation The WDT forces the device into the Reset state if it is configured to generate a Reset when a time-out occurs; the WDT status bit is set to 1 (for details, see the Reset Status Register section on page 40). For more information about Reset and the WDT status bit, see the Reset, Stop Mode Recovery and Low-Voltage Detection section on page 31. Following a Reset sequence, the WDT Counter is initialized with its reset value. 11.1.2.4. WDT Reset in STOP Mode If enabled in STOP Mode and configured to generate a Reset when a time-out occurs and the device is in STOP Mode, the WDT initiates a Stop Mode Recovery. Both the WDT status bit and the stop bit in the Reset Status Register (RSTSTAT) are set to 1 following a WDT time-out in STOP Mode. For more information, see the Reset, Stop Mode Recovery and Low-Voltage Detection section on page 31. 11.1.3. Watchdog Timer Reload Unlock Sequence Writing the unlock sequence to the Watchdog Timer Reload High (WDTH) Register address unlocks the two Watchdog Timer Reload registers (WDTH and WDTL) to allow changes to the time-out period. These write operations to the WDTH Register address produce no effect on the bits in the WDTH Register. The locking mechanism prevents unwarranted writes to the Reload registers. The following sequence is required to unlock the Watchdog Timer Reload registers (WDTH and WDTL) for write access. 1. Write 55h to the Watchdog Timer Reload High Register (WDTH). 2. Write AAh to the Watchdog Timer Reload High Register (WDTH). 3. Write the appropriate value to the Watchdog Timer Reload High Register (WDTH). 4. Write the appropriate value to the Watchdog Timer Reload Low Register (WDTL). After this write occurs, the Watchdog Timer Reload registers are again locked. All steps of the WDT Reload Unlock sequence must be written in the sequence defined above. The values in these WDT Reload registers are loaded into the counter every time a WDT instruction is executed. 11.2. Watchdog Timer Register Definitions The two Watchdog Timer Reload registers (WDTH and WDTL) are described in the following tables. PS025016-1013 PRELIMINARY Watchdog Timer Z8 Encore! XP® F1680 Series Product Specification 143 11.2.1. Watchdog Timer Reload High and Low Byte Registers The Watchdog Timer Reload High and Low Byte (WDTH, WDTL) registers, shown in Tables 81 and 82, form the 16-bit reload value that is loaded into the Watchdog Timer when a WDT instruction executes; this 16-bit reload value is {WDTH[7:0], WDTL[7:0]}. Writing to these registers following the unlock sequence sets the appropriate reload value. Reading from these registers returns the current WDT count value. Table 81. Watchdog Timer Reload High Byte Register (WDTH = FF2h) Bit 7 6 5 4 Field 2 1 0 WDTH Reset R/W 3 0 0 0 0 0 0 0 0 R/W R/W R/W R/W R/W R/W R/W R/W Address FF2h Table 82. Watchdog Timer Reload Low Byte Register Bit 7 6 5 4 Field 3 2 1 0 WDTL Reset R/W (WDTL = FF3h) 0 0 0 0 0 0 0 0 R/W R/W R/W R/W R/W R/W R/W R/W Address FF3h Bit Description [7:0] WDTH, WDTL Watchdog Timer Reload High and Low Bytes WDTH: The WDT Reload High Byte is the most significant byte, or bits [15:8] of the 16-bit WDT reload value. WDTL: The WDT Reload Low Byte is the least significant byte, or bits [7:0] of the 16-bit WDT reload value. PS025016-1013 PRELIMINARY Watchdog Timer Z8 Encore! XP® F1680 Series Product Specification 144 Chapter 12. LIN-UART The Local Interconnect Network Universal Asynchronous Receiver/Transmitter (LINUART) is a full-duplex communication channel capable of handling asynchronous data transfers in standard UART applications and providing LIN protocol support. The LINUART is a superset of the standard Z8 Encore!® UART, providing all its standard features, LIN protocol support and a digital noise filter. LIN-UART includes the following features: • • • • 8-bit asynchronous data transfer • • • Separate transmit and receive interrupts • • Driver Enable output for external bus transceivers • Configuring digital-noise filter on Receive Data line Selectable even- and odd-parity generation and checking Option of 1 or 2 stop bits Selectable MULTIPROCESSOR (9-bit) Mode with three configurable interrupt schemes Framing, parity, overrun and break detection 16-bit baud rate generator (BRG) which can function as a general purpose timer with interrupt LIN protocol support for both MASTER and SLAVE modes: – Break generation and detection – Selectable Slave Autobaud – Check Tx versus Rx data when sending 12.1. LIN-UART Architecture The LIN-UART consists of three primary functional blocks: transmitter, receiver and baud-rate generator. The LIN-UART’s transmitter and receiver function independently but use the same baud rate and data format. The basic UART operation is enhanced by the Noise Filter and IrDA blocks. Figure 19 displays the LIN-UART architecture. PS025016-1013 PRELIMINARY LIN-UART Z8 Encore! XP® F1680 Series Product Specification 145 Figure 19. LIN-UART Block Diagram 12.1.1. Data Format for Standard UART Modes The LIN-UART always transmits and receives data in an 8-bit data format with the least significant bit first. An even-or-odd parity bit or multiprocessor address/data bit can be optionally added to the data stream. Each character begins with an active Low start bit and ends with either 1 or 2 active High stop bits. Figures 20 and 21 display the asynchronous data format employed by the LIN-UART without parity and with parity, respectively. PS025016-1013 PRELIMINARY LIN-UART Z8 Encore! XP® F1680 Series Product Specification 146 Figure 20. LIN-UART Asynchronous Data Format without Parity Figure 21. LIN-UART Asynchronous Data Format with Parity 12.1.2. Transmitting Data using the Polled Method Observe the following steps to transmit data using the polled-operating method: 1. Write to the LIN-UART Baud Rate High and Low Byte registers to set the appropriate baud rate. 2. Enable the LIN-UART pin functions by configuring the associated GPIO port pins for alternate-function operation. 3. If MULTIPROCESSOR Mode is appropriate, write to the LIN-UART Control 1 Register to enable MULTIPROCESSOR (9-bit) Mode functions. 4. Set the MULTIPROCESSOR Mode Select bit (MPEN) to enable MULTIPROCESSOR Mode. 5. Write to the LIN-UART Control 0 Register to: a. Set the Transmit Enable bit (TEN) to enable the LIN-UART for data transmission. b. If parity is appropriate and MULTIPROCESSOR Mode is not enabled, set the parity enable bit (PEN) and select either even-or-odd parity (PSEL). c. Set or clear the CTSE bit to enable or disable control from the remote receiver using the CTS pin. PS025016-1013 PRELIMINARY LIN-UART Z8 Encore! XP® F1680 Series Product Specification 147 6. Check the TDRE bit in the LIN-UART Status 0 Register to determine if the Transmit Data Register is empty (indicated by a 1); if empty, continue to Step 7. If the Transmit Data Register is full (indicated by a 0), continue to monitor the TDRE bit until the Transmit Data Register becomes available to receive new data. 7. If operating in MULTIPROCESSOR Mode, write to the LIN-UART Control 1 Register to select the outgoing address bit. – Set the Multiprocessor Bit Transmitter (MPBT) if sending an address byte; clear it if sending a data byte. 8. Write the data byte to the LIN-UART Transmit Data Register. The transmitter automatically transfers the data to the Transmit Shift Register and transmits the data. 9. If appropriate – and if MULTIPROCESSOR Mode is enabled – changes can be made to the Multiprocessor Bit Transmitter (MPBT) value. 10. To transmit additional bytes, return to Step 5. 12.1.3. Transmitting Data Using Interrupt-Driven Method The LIN-UART Transmitter interrupt indicates the availability of the Transmit Data Register to accept new data for transmission. Observe the following steps to configure the LIN-UART for interrupt-driven data transmission: 1. Write to the LIN-UART Baud Rate High and Low Byte registers to set the appropriate baud rate. 2. Enable the LIN-UART pin functions by configuring the associated GPIO port pins for alternate function operation. 3. Execute a DI instruction to disable interrupts. 4. Write to the interrupt control registers to enable the LIN-UART Transmitter interrupt and set the appropriate priority. 5. If MULTIPROCESSOR Mode is appropriate, write to the LIN-UART Control 1 Register to enable MULTIPROCESSOR (9-bit) Mode functions. 6. Set the MULTIPROCESSOR Mode Select bit (MPEN) to enable MULTIPROCESSOR Mode. 7. Write to the LIN-UART Control 0 Register to: a. Set the transmit enable bit (TEN) to enable the LIN-UART for data transmission. b. If MULTIPROCESSOR Mode is not enabled, then enable parity if appropriate and select either even or odd parity. c. Set or clear the CTSE bit to enable or disable control from the remote receiver via the CTS pin. PS025016-1013 PRELIMINARY LIN-UART Z8 Encore! XP® F1680 Series Product Specification 148 8. Execute an EI instruction to enable interrupts. The LIN-UART is now configured for interrupt-driven data transmission. Because the LIN-UART Transmit Data Register is empty, an interrupt is generated immediately. When the LIN-UART Transmit interrupt is detected and there is transmit data ready to send, the associated interrupt service routine (ISR) performs the following: 1. If in MULTIPROCESSOR Mode, writes to the LIN-UART Control 1 Register to select the outgoing address bit: – Sets the Multiprocessor Bit Transmitter (MPBT) if sending an address byte, clears it if sending a data byte. 2. Writes the data byte to the LIN-UART Transmit Data Register. The transmitter automatically transfers the data to the Transmit Shift Register and transmits the data. 3. Executes the IRET instruction to return from the interrupt-service routine and wait for the Transmit Data Register to again become empty. If a transmit interrupt occurs and there is no transmit data ready to send, the interrupt service routine executes the IRET instruction. When the application does have data to transmit, software can set the appropriate interrupt request bit in the Interrupt Controller to initiate a new transmit interrupt. Another alternative would be for the software to write the data to the Transmit Data Register instead of invoking the interrupt service routine. 12.1.4. Receiving Data Using Polled Method Observe the following steps to configure the LIN-UART for polled data reception: 1. Write to the LIN-UART Baud Rate High and Low Byte registers to set the appropriate baud rate. 2. Enable the LIN-UART pin functions by configuring the associated GPIO port pins for alternate function operation. 3. If MULTIPROCESSOR Mode is appropriate, write to the LIN-UART Control 1 Register to enable MULTIPROCESSOR (9-bit) Mode functions. 4. Write to the LIN-UART Control 0 Register to: a. Set the Receive Enable bit (REN) to enable the LIN-UART for data reception. b. If MULTIPROCESSOR Mode is not enabled, then enable parity (if appropriate), and select either even or odd parity. 5. Check the RDA bit in the LIN-UART Status 0 Register to determine if the Receive Data Register contains a valid data byte (indicated by a 1). If RDA is set to 1 to indicate available data, continue to Step 6. If the Receive Data Register is empty (indicated by a 0), continue to monitor the RDA bit that is awaiting reception of the valid data. PS025016-1013 PRELIMINARY LIN-UART Z8 Encore! XP® F1680 Series Product Specification 149 6. Read data from the LIN-UART Receive Data Register. If operating in MULTIPROCESSOR (9-bit) Mode, further actions may be required depending on the MULTIPROCESSOR Mode bits MPMD[1:0]. 7. Return to Step 5 to receive additional data. 12.1.5. Receiving Data Using the Interrupt-Driven Method The LIN-UART Receiver interrupt indicates the availability of new data (as well as error conditions). Observe the following steps to configure the LIN-UART receiver for interrupt-driven operation: 1. Write to the LIN-UART Baud Rate High and Low Byte registers to set the appropriate baud rate. 2. Enable the LIN-UART pin functions by configuring the associated GPIO port pins for alternate function operation. 3. Execute a DI instruction to disable interrupts. 4. Write to the Interrupt Control registers to enable the LIN-UART Receiver interrupt and set the appropriate priority. 5. Clear the LIN-UART Receiver interrupt in the applicable Interrupt Request Register. 6. Write to the LIN-UART Control 1 Register to enable MULTIPROCESSOR (9-bit) Mode functions, if appropriate. a. Set the MULTIPROCESSOR Mode Select bit (MPEN) to enable MULTIPROCESSOR Mode. b. Set the MULTIPROCESSOR Mode Bits, MPMD[1:0] to select the appropriate address matching scheme. c. Configure the LIN-UART to interrupt on received data and errors or errors only (interrupt on errors only is unlikely to be useful for Z8 Encore! devices without a DMA block). 7. Write the device address to the Address Compare Register (automatic MULTIPROCESSOR Modes only). 8. Write to the LIN-UART Control 0 Register to: a. Set the receive enable bit (REN) to enable the LIN-UART for data reception. b. If MULTIPROCESSOR Mode is not enabled, then enable parity (if appropriate) and select either even or odd parity. 9. Execute an EI instruction to enable interrupts. PS025016-1013 PRELIMINARY LIN-UART Z8 Encore! XP® F1680 Series Product Specification 150 The LIN-UART is now configured for interrupt-driven data reception. When the LINUART Receiver interrupt is detected, the associated ISR performs the following: 1. Checks the LIN-UART Status 0 Register to determine the source of the interrupt-error, break, or received data. 2. If the interrupt is due to data available, read the data from the LIN-UART Receive Data Register. If operating in MULTIPROCESSOR (9-bit) Mode, further actions may be required depending on the MULTIPROCESSOR Mode bits MPMD[1:0]. 3. Execute the IRET instruction to return from the ISR and await more data. 12.1.6. Clear To Send Operation The Clear To Send (CTS) pin, if enabled by the CTSE bit of the LIN-UART Control 0 Register performs flow control on the outgoing transmit data stream. The Clear To Send (CTS) input pin is sampled one system clock before any new character transmission begins. To delay transmission of the next data character, an external receiver must reduce CTS at least one system clock cycle before a new data transmission begins. For multiple character transmissions, this operation is typically performed during the stop bit transmission. If CTS stops in the middle of a character transmission, the current character is sent completely. 12.1.7. External Driver Enable The LIN-UART provides a Driver Enable (DE) signal for off-chip bus transceivers. This feature reduces the software overhead associated using a GPIO pin to control the transceiver when communicating on a multitransceiver bus, such as RS-485. Driver Enable is a programmable polarity signal which envelopes the entire transmitted data frame including parity and stop bits as illustrated in Figure 22. The Driver Enable signal asserts when a byte is written to the LIN-UART Transmit Data Register. The Driver Enable signal asserts at least one bit period and no greater than two bit periods before the start bit is transmitted. This allows a set-up time to enable the transceiver. The Driver Enable signal deasserts one system clock period after the last stop bit is transmitted. This system clock delay allows both time for data to clear the transceiver before disabling it, as well as the ability to determine if another character follows the current character. In the event of back-to-back characters (new data must be written to the Transmit Data Register before the previous character is completely transmitted) the DE signal is not deasserted between characters. The DEPOL bit in the LIN-UART Control Register 1 sets the polarity of the Driver Enable signal. PS025016-1013 PRELIMINARY LIN-UART Z8 Encore! XP® F1680 Series Product Specification 151 Figure 22. LIN-UART Driver Enable Signal Timing with One Stop Bit and Parity The Driver Enable to start bit set-up time is calculated as follows: 1 Baud Rate (Hz) ≤ DE to Start Bit Set-up Time(s) ≤ 2 Baud Rate (Hz) 12.1.8. LIN-UART Special Modes The special modes of the LIN-UART are: • • MULTIPROCESSOR Mode LIN Mode The LIN-UART features a common control register (Control 0) that has a unique register address and several mode-specific control registers (Multiprocessor Control, Noise Filter Control and LIN Control) that share a common register address (Control 1). When the Control 1 address is read or written, the MSEL[2:0] (Mode Select) field of the Mode Select and Status Register determines which physical register is accessed. Similarly, there are mode-specific status registers, one of which is returned when the Status 0 Register is read depending on the MSEL field. 12.1.9. MULTIPROCESSOR Mode The LIN-UART features a MULTIPROCESSOR (9-bit) Mode that uses an extra (9th) bit for selective communication when a number of processors share a common UART bus. In MULTIPROCESSOR Mode (also referred to as 9-bit mode), the multiprocessor bit (MP) is transmitted immediately following the 8 bits of data and immediately preceding the stop bit(s) as displayed in Figure 23. PS025016-1013 PRELIMINARY LIN-UART Z8 Encore! XP® F1680 Series Product Specification 152 Figure 23. LIN-UART Asynchronous MULTIPROCESSOR Mode Data Format In MULTIPROCESSOR (9-bit) Mode, the Parity bit location (9th bit) becomes the Multiprocessor control bit. The LIN-UART Control 1 and Status 1 registers provide MULTIPROCESSOR (9-bit) Mode control and status information. If an automatic address matching scheme is enabled, the LIN-UART Address Compare register holds the network address of the device. 12.1.9.1. MULTIPROCESSOR Mode Receive Interrupts When MULTIPROCESSOR (9-bit) Mode is enabled, the LIN-UART processes only frames addressed to it. To determine whether a frame of data is addressed to the LINUART can be made in hardware, software or a combination of the two, depending on the multiprocessor configuration bits. In general, the address compare feature reduces the load on the CPU, because it is not required to access the LIN-UART when it receives data directed to other devices on the multinode network. The following three MULTIPROCESSOR Modes are available in hardware: • • • Interrupt on all address bytes Interrupt on matched address bytes and correctly framed data bytes Interrupt only on correctly framed data bytes These modes are selected with MPMD[1:0] in the LIN-UART Control 1 Register. For all MULTIPROCESSOR Modes, bit MPEN of the LIN-UART Control 1 Register must be set to 1. The first scheme is enabled by writing 01b to MPMD[1:0]. In this mode, all incoming address bytes cause an interrupt, while data bytes never cause an interrupt. The interrupt service routine checks the address byte which triggered the interrupt. If it matches the LIN-UART address, the software clears MPMD[0]. At this point, each new incoming byte interrupts the CPU. The software determines the end of the frame and checks for it by reading the MPRX bit of the LIN-UART Status 1 Register for each incoming byte. If MPRX = 1, a new frame begins. If the address of this new frame is different from the LINUART’s address, then MPMD[0] must be set to 1 by software, causing the LIN-UART PS025016-1013 PRELIMINARY LIN-UART Z8 Encore! XP® F1680 Series Product Specification 153 interrupts to go inactive until the next address byte. If the new frame’s address matches the LIN-UART’s, then the data in the new frame is also processed. The second scheme is enabled by setting MPMD[1:0] to 10B and writing the LIN-UART’s address into the LIN-UART Address Compare Register. This mode introduces more hardware control, interrupting only on frames that match the LIN-UART’s address. When an incoming address byte does not match the LIN-UART’s address, it is ignored. All successive data bytes in this frame are also ignored. When a matching address byte occurs, an interrupt is issued and further interrupts occur on each successive data byte. The first data byte in the frame has NEWFRM=1 in the LIN-UART Status 1 Register. When the next address byte occurs, the hardware compares it to the LIN-UART’s address. If there is a match, the interrupt occurs and the NEWFRM bit is set to the first byte of the new frame. If there is no match, the LIN-UART ignores all incoming bytes until the next address match. The third scheme is enabled by setting MPMD[1:0] to 11B and by writing the LINUART’s address into the LIN-UART Address Compare Register. This mode is identical to the second scheme, except that there are no interrupts on address bytes. The first data byte of each frame remains accompanied by a NEWFRM assertion. 12.1.10. LIN Protocol Mode The Local Interconnect Network (LIN) protocol as supported by the LIN-UART module is defined in rev 2.0 of the LIN Specification Package. The LIN protocol specification covers all aspects of transferring information between LIN Master and Slave devices using message frames including error detection and recovery, SLEEP Mode and wake-up from SLEEP Mode. The LIN-UART hardware in LIN mode provides character transfers to support the LIN protocol including break transmission and detection, wake-up transmission and detection and slave autobauding. Part of the error detection of the LIN protocol is for both master and slave devices to monitor their receive data when transmitting. If the receive and transmit data streams do not match, the LIN-UART asserts the PLE bit (physical layer error bit in Status 0 Register). The message frame time-out aspect of the protocol depends on software requiring the use of an additional general purpose timer. The LIN mode of the LIN-UART does not provide any hardware support for computing/verifying the checksum field or verifying the contents of the identifier field. These fields are treated as data and are not interpreted by hardware. The checksum calculation/verification can easily be implemented in software via the ADC (Add with Carry) instruction. The LIN bus contains a single Master and one or more Slaves. The LIN master is responsible for transmitting the message frame header which consists of the Break, Synch and Identifier fields. Either the master or one of the slaves transmits the associated response section of the message which consists of data characters followed by a checksum character. PS025016-1013 PRELIMINARY LIN-UART Z8 Encore! XP® F1680 Series Product Specification 154 In LIN mode, the interrupts defined for normal UART operation still apply with the following changes: • A Parity Error (the PE bit in the Status 0 Register) is redefined as the Physical Layer Error (PLE) bit. The PLE bit indicates that receive data does not match transmit data when the LIN-UART is transmitting. This definition applies to both Master and Slave operating modes. • The Break Detect interrupt (BRKD bit in Status 0 Register) indicates when a Break is detected by the slave (break condition for at least 11 bit times). Software can use this interrupt to start a timer checking for message frame time-out. The duration of the break can be read in the RxBreakLength[3:0] field of the Mode Select and Status Register. • The Break Detect interrupt (BRKD bit in Status 0 Register) indicates when a wake-up message has been received, if the LIN-UART is in LIN SLEEP state. • In LIN SLAVE Mode, if the BRG counter overflows while measuring the autobaud period (from the start bit to the beginning of bit 7 of the autobaud character), an Overrun Error is indicated (OE bit in the Status 0 Register). In this case, software sets the LINSTATE field back to 10b, where the slave ignores the current message and waits for the next break. The Baud Reload High and Low registers are not updated by hardware if this autobaud error occurs. The OE bit is also set if a data overrun error occurs. 12.1.10.1. LIN System Clock Requirements The LIN Master provides the timing reference for the LIN network and is required to have a clock source with a tolerance of ±0.5%. A slave with autobaud capability is required to have a baud clock matching the master oscillator within ±14%. The slave nodes autobaud to lock onto the master timing reference with an accuracy of ±2%. If a slave does not contain autobaud capability, it must include a baud clock which deviates from the masters by not more than ±1.5%. These accuracy requirements must include the effects such as voltage and temperature drift during operation. Before sending/receiving messages, the Baud Reload High/Low registers must be initialized. Unlike standard UART modes, the Baud Reload High/Low registers must be loaded with the baud interval rather than 1/16 of the baud interval. In order to autobaud with the required accuracy, the LIN SLAVE system clock must be at least 100 times the baud rate. 12.1.10.2. LIN Mode Initialization and Operation The LIN protocol mode is selected by setting either the LIN Master (LMST) or LIN SLAVE (LSLV) and optionally (for the LIN SLAVE) the Autobaud Enable (ABEN) bits in the LIN Control Register. To access the LIN Control Register, the Mode Select (MSEL) field of the LIN-UART Mode Select/Status Register must be equal to 010B. The LIN- PS025016-1013 PRELIMINARY LIN-UART Z8 Encore! XP® F1680 Series Product Specification 155 UART Control 0 Register must be initialized with TEN = 1, REN = 1 and all other bits = 0. In addition to the LMST, LSLV and ABEN bits in the LIN Control Register, a LinState[1:0] field exists which defines the current state of the LIN logic. This field is initially set by software. In the LIN SLAVE Mode, the LinState field is updated by hardware as the slave moves through the Wait For Break, AutoBaud and Active states. 12.1.10.3. LIN MASTER Mode Operation LIN MASTER Mode is selected by setting LMST = 1, LSLV = 0, ABEN = 0 and LinState[1:0] = 11B. If the LIN bus protocol indicates the bus is required go into the LIN SLEEP state, the LinState[1:0] bits must be set to 00B by software. The break is the first part of the message frame transmitted by the master, consisting of at least 13 bit periods of logical zero on the LIN bus. During initialization of the LIN master, the duration (in bit times) of the break is written to the TxBreakLength field of the LIN Control Register. The transmission of the break is performed by setting the SBRK bit in the Control 0 Register. The LIN-UART starts the break after the SBRK bit is set and any character transmission currently underway has completed. The SBRK bit is deasserted by hardware until the break is completed. If it is necessary to generate a break longer than 15 bit times, the SBRK bit can be used in normal UART mode where software times the duration of the break. The Synch character is transmitted by writing a 55h to the Transmit Data Register (TDRE must = 1 before writing). The Synch character is not transmitted by the hardware until the break is complete. The identifier character is transmitted by writing the appropriate value to the Transmit Data Register (TDRE must = 1 before writing). If the master is sending the response portion of the message, these data and checksum characters are written to the Transmit Data Register when the TDRE bit asserts. If the Transmit Data Register is written after TDRE asserts, but before TXE asserts, the hardware inserts one or two stop bits between each character as determined by the stop bit in the Control 0 Register. Additional idle time occurs between characters, if TXE asserts before the next character is written. If the selected slave is sending the response portion of the frame to the master, each receive byte will be signalled by the receive data interrupt (RDA bit will be set in the Status 0 Register). If the selected slave is sending the response to a different slave, the master can ignore the response characters by deasserting the REN bit in the Control 0 Register until the frame time slot is completed. 12.1.10.4. LIN SLEEP Mode While the LIN bus is in the sleep state, the CPU can either be in low power STOP Mode, in HALT Mode, or in normal operational state. Any device on the LIN bus can issue a PS025016-1013 PRELIMINARY LIN-UART Z8 Encore! XP® F1680 Series Product Specification 156 Wake-up message if it requires the master to initiate a LIN message frame. Following the Wake-up message, the master wakes up and initiates a new message. A Wake-up message is accomplished by pulling the bus Low for at least 250 µs but less than 5 ms. Transmitting a 00h character is one way to transmit the Wake-up message. If the CPU is in STOP Mode, the LIN-UART is not active and the Wake-up message must be detected by a GPIO edge detect Stop Mode Recovery. The duration of the Stop Mode Recovery sequence can preclude making an accurate measurement of the Wake-up message duration. If the CPU is in HALT or OPERATIONAL mode, the LIN-UART (if enabled) times the duration of the Wake-up and provides an interrupt following the end of the break sequence if the duration is ≥ 3 bit times. The total duration of the Wake-up message in bit times can be obtained by reading the RxBreakLength field in the Mode Select and Status register. After a Wake-up message has been detected, the LIN-UART can be placed (by software) either into LIN Master or LIN Slave Wait for Break states as appropriate. If the break duration exceeds 15 bit times, the RxBreakLength field contains the value Fh. If the LINUART is disabled, Wake-up message is detected via a port pin interrupt and timed by software. If the device is in STOP Mode, the High to Low transition on the port pin will bring the device out of STOP Mode. The LIN Sleep state is selected by software setting LinState[1:0] = 00. The decision to move from an active state to sleep state is based on the LIN messages as interpreted by software. 12.1.10.5. LIN Slave Operation LIN SLAVE Mode is selected by setting LMST = 0, LSLV = 1, ABEN = 1 or 0 and LinState[1:0] = 01b (Wait for Break state). The LIN slave detects the start of a new message by the break which appears to the Slave as a break of at least 11 bit times in duration. The LIN-UART detects the break and generates an interrupt to the CPU. The duration of the break is observable in the RxBreakLength field of the Mode Select and Status register. A break of less than 11 bit times in duration does not generate a break interrupt when the LIN-UART is in Wait for Break state. If the break duration exceeds 15 bit times, the RxBreakLength field contains the value Fh. Following the break, the LIN-UART hardware automatically transits to the Autobaud state, where it autobauds by timing the duration of the first 8 bit times of the Synch character as defined in the LIN standard. The duration of the autobaud period is measured by the BRG Counter which will update every 8th system clock cycle between the start bit and the beginning of bit 7 of the autobaud sequence. At the end of the autobaud period, the duration measured by the BRG counter (auto baud period divided by 8) is automatically transferred to the Baud Reload High and Low registers if the ABEN bit of the LIN control register is set. If the BRG Counter overflows before reaching the start of bit 7 in the autobaud sequence the Autobaud Overrun Error interrupt occurs, the OE bit in the Status 0 Register is set and the Baud Reload registers are not updated. To autobaud within 2% of the master’s baud rate, the slave system clock must be a minimum of 100 times the baud PS025016-1013 PRELIMINARY LIN-UART Z8 Encore! XP® F1680 Series Product Specification 157 rate. To avoid an autobaud overrun error, the system clock must not be greater than 219 times the baud rate (16 bit counter following 3-bit prescaler when counting the 8 bit times of the Autobaud sequence). Following the Synch character, the LIN-UART hardware transits to the Active state, in which the identifier character is received and the characters of the response section of the message are sent or received. The slave remains in this Active state until a break is received or software forces a state change. After it is in an Active state (i.e., autobaud has completed), a break of 10 or more bit times is recognized and causes a transition to the Autobaud state. If the identifier character indicates that this slave device is not participating in the message, software sets the LinState[1:0] = 01b (Wait for Break state) to ignore the rest of the message. No further receive interrupts will occur until the next break. 12.1.11. LIN-UART Interrupts The LIN-UART features separate interrupts for the transmitter and receiver. In addition, when the LIN-UART primary functionality is disabled, the Baud Rate Generator can also function as a basic timer with interrupt capability. 12.1.11.1. Transmitter Interrupts The transmitter generates a single interrupt when the Transmit Data Register Empty bit (TDRE) is set to 1. This indicates that the transmitter is ready to accept new data for transmission. The TDRE interrupt occurs when the transmitter is initially enabled and after the Transmit Shift Register has shifted out the first bit of a character. At this point, the Transmit Data Register can be written with the next character to send. This provides 7 bit periods of latency to load the Transmit Data Register before the Transmit Shift Register completes shifting the current character. Writing to the LIN-UART Transmit Data Register clears the TDRE bit to 0. 12.1.11.2. Receiver Interrupts The receiver generates an interrupt when any one of the following occurs: • PS025016-1013 A data byte has been received and is available in the LIN-UART Receive Data Register. This interrupt can be disabled independent of the other receiver interrupt sources via the RDAIRQ bit (this feature is useful in devices which support DMA). The received data interrupt occurs after the receive character has been placed in the Receive Data Register. Software must respond to this received data available condition before the next character is completely received to avoid an overrun error. PRELIMINARY LIN-UART Z8 Encore! XP® F1680 Series Product Specification 158 Note: In MULTIPROCESSOR Mode (MPEN=1), the receive-data interrupts are dependent on the multiprocessor configuration and the most recent address byte. • • • • A break is received A Receive Data Overrun or LIN Slave Autobaud Overrun Error is detected A Data Framing Error is detected A Parity Error is detected (physical layer error in LIN mode) 12.1.11.3. LIN-UART Overrun Errors When an overrun error condition occurs, the LIN-UART prevents overwriting of the valid data currently in the Receive Data Register. The Break Detect and Overrun status bits are not displayed until after the valid data has been read. After the valid data has been read, the OE bit of the Status 0 register is updated to indicate the overrun condition (and Break Detect, if applicable). The RDA bit is set to 1 to indicate that the Receive Data Register contains a data byte. However, because the overrun error occurred, this byte cannot contain valid data and must be ignored. The BRKD bit indicates if the overrun is caused by a break condition on the line. After reading the status byte indicating an overrun error, the Receive Data Register must be read again to clear the error bits in the LIN-UART Status 0 Register. In LIN mode, an Overrun Error is signalled for receive-data overruns as described above and in the LIN Slave if the BRG Counter overflows during the autobaud sequence (the ATB bit will also be set in this case). There is no data associated with the autobaud overflow interrupt; however the Receive Data Register must be read to clear the OE bit. In this case, software must write a 10B to the LinState field, forcing the LIN slave back to a Wait for Break state. 12.1.11.4. LIN-UART Data- and Error-Handling Procedure Figures 24 displays the recommended procedure for use in LIN-UART receiver interrupt service routines. PS025016-1013 PRELIMINARY LIN-UART Z8 Encore! XP® F1680 Series Product Specification 159 Figure 24. LIN-UART Receiver Interrupt Service Routine Flow 12.1.11.5. Baud Rate Generator Interrupts If the BRGCTL bit of the Multiprocessor Control Register (LIN-UART Control 1 Register with MSEL = 000b) is set and the REN bit of the Control 0 Register is 0. The LIN-UART Receiver interrupt asserts when the LIN-UART Baud Rate Generator reloads. This action allows the Baud Rate Generator to function as an additional counter, if the LIN-UART receiver functionality is not employed. The transmitter can be enabled in this mode. PS025016-1013 PRELIMINARY LIN-UART Z8 Encore! XP® F1680 Series Product Specification 160 12.1.12. LIN-UART Baud Rate Generator The LIN-UART Baud Rate Generator creates a lower frequency baud rate clock for data transmission. The input to the Baud Rate Generator is the system clock. The LIN-UART Baud Rate High and Low Byte registers combine to create a 16-bit baud rate divisor value (BRG[15:0]) that sets the data-transmission rate (baud rate) of the LIN-UART. The LINUART data rate for normal UART operation is calculated using the following equation: System Clock Frequency (Hz) UART Data Rate (bits/s) = 16 x UART Baud Rate Divisor Value The LIN-UART data rate for LIN mode UART operation is calculated using the following equation: System Clock Frequency (Hz) UART Data Rate (bits/s) = UART Baud Rate Divisor Value When the LIN-UART is disabled, the BRG functions as a basic 16-bit timer with interrupt on time-out. To configure the BRG as a timer with interrupt on time-out, follow the procedure below: 1. Disable the LIN-UART receiver by clearing the REN bit in the LIN-UART Control 0 Register to 0 (i.e., the TEN bit can be asserted; transmit activity can occur). 2. Load the appropriate 16-bit count value into the LIN-UART Baud Rate High and Low Byte registers. 3. Enable the BRG timer function and the associated interrupt by setting the BRGCTL bit in the LIN-UART Control 1 Register to 1. 12.2. Noise Filter A noise filter circuit is included which filters noise on a digital input signal (such as UART Receive Data) before the data is sampled by the block. This noise filter is likely to be a requirement for protocols with a noisy environment. The noise filter contains the following features: • • PS025016-1013 Synchronizes the receive input data to the System Clock Noise Filter Enable (NFEN) input selects whether the noise filter is bypassed (NFEN = 0) or included (NFEN = 1) in the receive data path PRELIMINARY LIN-UART Z8 Encore! XP® F1680 Series Product Specification 161 • Noise Filter Control (NFCTL[2:0]) input selects the width of the up/down saturating counter digital filter; the available width ranges from 4 to 11 bits • • The digital filter output features hysteresis Provides an active low Saturated State output (FiltSatB) which is used as an indication of the presence of noise 12.2.1. Architecture Figure 25 displays how the noise filter is integrated with the LIN-UART on a LIN network. Figure 25. Noise Filter System Block Diagram 12.2.2. Operation Figure 26 displays the operation of the noise filter both with and without noise. The noise filter in this example is a 2-bit up/down counter which saturates at 00b and 11b. A 2-bit counter is shown for convenience, the operation of wider counters is similar. The output of the filter switches from 1 to 0, when the counter counts down from 01b to 00b; and switches from 0 to 1, when the counter counts up from 10b to 11b. The noise filter delays the receive data by three System Clock cycles. The FiltSatB signal is checked when the filtered RxD is sampled in the center of the bit time. The presence of noise (FiltSatB = 1 at center of bit time) does not mean that the sampled data is incorrect, but just that the filter is not in its ‘saturated’ state of all 1s or all 0s. If FiltSatB = 1 then RxD is sampled during a receive character, the NE bit in the PS025016-1013 PRELIMINARY LIN-UART Z8 Encore! XP® F1680 Series Product Specification 162 ModeStatus[4:0] field is set. By observing this bit, an indication of the level of noise in the network can be obtained. Figure 26. Noise Filter Operation PS025016-1013 PRELIMINARY LIN-UART Z8 Encore! XP® F1680 Series Product Specification 163 12.3. LIN-UART Control Register Definitions The LIN-UART control registers support the LIN-UART, the associated Infrared Encoder/ Decoder and the noise filter. For more information about the infrared operation, see the Infrared Encoder/Decoder section on page 182. 12.3.1. LIN-UART Transmit Data Register Data bytes written to the LIN-UART Transmit Data Register, shown in Table 83, are shifted out on the TxD pin. The write-only LIN-UART Transmit Data Register shares a Register File address with the read-only LIN-UART Receive Data Register. Table 83. LIN-UART Transmit Data Register (U0TXD = F40h) Bit 7 6 5 4 Field 3 2 1 0 TxD Reset X X X X X X X X R/W W W W W W W W W Address F40h, F48h Note: W = Write; X = undefined. Bit Description [7:0] TxD Transmit Data LIN–UART transmitter data byte to be shifted out through the TxD pin. PS025016-1013 PRELIMINARY LIN-UART Z8 Encore! XP® F1680 Series Product Specification 164 12.3.2. LIN-UART Receive Data Register Data bytes received through the RxD pin are stored in the LIN-UART Receive Data Register as shown in Table 84. The read-only LIN-UART Receive Data Register shares a Register File address with the write-only LIN-UART Transmit Data Register. Table 84. LIN-UART Receive Data Register (U0RXD = F40h) Bit 7 6 5 4 Field 3 2 1 0 RxD Reset X X X X X X X X R/W R R R R R R R R Address F40h, F48h Note: R = Read. Bit Description [7:0] RxD Receive Data LIN–UART receiver data byte from the RxD pin. PS025016-1013 PRELIMINARY LIN-UART Z8 Encore! XP® F1680 Series Product Specification 165 12.3.3. LIN-UART Status 0 Register The LIN-UART Status 0 Register identifies the current LIN-UART operating configuration and status. Table 85 describes the Status 0 Register for standard UART mode. Table 86 describes the Status 0 Register for LIN mode. Table 85. LIN-UART Status 0 Register—Standard UART Mode (U0STAT0 = F41h) Bit 7 6 5 4 3 2 1 0 Field RDA PE OE FE BRKD TDRE TXE CTS Reset 0 0 0 0 0 1 1 X R/W R R R R R R R R Address F41h, F49h Note: R = Read; X = undefined. Bit Description [7] RDA Receive Data Available This bit indicates that the LIN-UART Receive Data Register has received data. Reading the LIN-UART Receive Data Register clears this bit. 0 = The LIN-UART Receive Data Register is empty. 1 = There is a byte in the LIN-UART Receive Data Register. [6] PE Parity Error This bit indicates that a parity error has occurred. Reading the Receive Data Register clears this bit. 0 = No parity error occurred. 1 = A parity error occurred. [5] OE Overrun Error This bit indicates that an overrun error has occurred. An overrun occurs when new data is received and the Receive Data Register is not read. Reading the Receive Data Register clears this bit. 0 = No overrun error occurred. 1 = An overrun error occurred. [4] FE Framing Error This bit indicates that a framing error (no stop bit following data reception) was detected. Reading the Receive Data Register clears this bit. 0 = No framing error occurred. 1 = A framing error occurred. [3] BRKD Break Detect This bit indicates that a break occurred. If the data bits, parity/multiprocessor bit and stop bit(s) are all zeros then this bit is set to 1. Reading the Receive Data Register clears this bit. 0 = No break occurred. 1 = A break occurred. PS025016-1013 PRELIMINARY LIN-UART Z8 Encore! XP® F1680 Series Product Specification 166 Bit Description (Continued) [2] TDRE Transmitter Data Register Empty This bit indicates that the Transmit Data Register is empty and ready for additional data. Writing to the Transmit Data Register resets this bit. 0 = Do not write to the Transmit Data Register. 1 = The Transmit Data Register is ready to receive an additional byte for transmission. [1] TXE Transmitter Empty This bit indicates that the Transmit Shift Register is empty and character transmission is finished. 0 = Data is currently transmitting. 1 = Transmission is complete. [0] CTS Clear to Send Signal When this bit is read it returns the level of the CTS signal. If LBEN = 1, the CTS input signal is replaced by the internal Receive Data Available signal to provide flow control in loopback mode. CTS only affects transmission if the CTSE bit = 1. Table 86. LIN-UART Status 0 Register—LIN Mode (U0STAT0 = F41h) Bit 7 6 5 4 3 2 1 0 Field RDA PLE OE FE BRKD TDRE TXE ATB Reset 0 0 0 0 0 1 1 0 R/W R R R R R R R R Address F41h, F49h Note: R = Read. Bit Description [7] RDA Receive Data Available This bit indicates that the Receive Data Register has received data. Reading the Receive Data Register clears this bit. 0 = The Receive Data Register is empty. 1 = There is a byte in the Receive Data Register. [6] PLE Physical Layer Error This bit indicates that transmit and receive data do not match when a LIN slave or master is transmitting. This could be by a fault in the physical layer or multiple devices driving the bus simultaneously. Reading the Status 0 Register or the Receive Data Register clears this bit. 0 = Transmit and Receive data match. 1 = Transmit and Receive data do not match. PS025016-1013 PRELIMINARY LIN-UART Z8 Encore! XP® F1680 Series Product Specification 167 Bit Description (Continued) [5] OE Receive Data and Autobaud Overrun Error This bit is set just as in normal UART operation if a receive data overrun error occurs. This bit is also set during LIN Slave autobaud if the BRG counter overflows before the end of the autobaud sequence. This indicates that the receive activity is not an autobaud character or the master baud rate is too slow. The ATB status bit will also be set in this case. This bit is cleared by reading the Receive Data Register. 0 = No autobaud or data overrun error occurred. 1 = An autobaud or data overrun error occurred. [4] FE Framing Error This bit indicates that a framing error (no stop bit following data reception) is detected. Reading the Receive Data Register clears this bit. 0 = No framing error occurred. 1 = A framing error occurred. [3] BRKD Break Detect This bit is set in LIN mode if: • It is in Lin Sleep state and a break of at least 4 bit times occurred (Wake-up event) or • It is in Slave Wait Break state and a break of at least 11 bit times occurred (Break event) or • It is in Slave Active state and a break of at least 10 bit times occurs. Reading the Status 0 Register or the Receive Data Register clears this bit. 0 = No LIN break occurred. 1 = LIN break occurred. [2] TDRE Transmitter Data Register Empty This bit indicates that the Transmit Data Register is empty and ready for additional data. Writing to the Transmit Data Register resets this bit. 0 = Do not write to the Transmit Data Register. 1 = The Transmit Data Register is ready to receive an additional byte for transmission. [1] TXE Transmitter Empty This bit indicates that the Transmit Shift Register is empty and character transmission is completed. 0 = Data is currently transmitting. 1 = Transmission is complete. [0] ATB LIN Slave Autobaud Complete This bit is set in LIN SLAVE Mode when an autobaud character is received. If the ABIEN bit is set in the LIN Control Register, then a receive interrupt is generated when this bit is set. Reading the Status 0 Register clears this bit. This bit will be 0 in LIN MASTER Mode. PS025016-1013 PRELIMINARY LIN-UART Z8 Encore! XP® F1680 Series Product Specification 168 12.3.4. LIN-UART Mode Select and Status Register The LIN-UART Mode Select and Status Register, shown in Table 87, contains mode select and status bits. Table 87. LIN-UART Mode Select and Status Register (U0MDSTAT = F44h) Bit 7 Field 5 4 3 MSEL Reset R/W 6 2 1 0 MODE STATUS 0 0 0 0 0 0 0 0 R/W R/W R/W R R R R R Address F44h, F4Ch Note: R = Read; R/W = Read/Write. Bit Description [7:5] MSEL Mode Select This read/write field determines which control register is accessed when performing a write or read to the UART Control 1 Register address. This field also determines which status is returned in the Mode Status field when reading this register. 000 = Multiprocessor and normal UART control/status 001 = Noise filter control/status 010 = LIN protocol control/status 011 = Reserved 100 = Reserved 101 = Reserved 110 = Reserved 111 = LIN-UART hardware revision (allows hardware revision to be read in the Mode Status field. [4:0] Mode Status This read-only field returns status corresponding to one of four modes selected by MSEL. These four modes are described in Table 88 on page 169. MSEL[2:0]=000, MULTIPROCESSOR Mode status = {0,0,0,NEWFRM, MPRX} MSEL[2:0]=001, Noise filter status = {NE,0,0,0,0} MSEL[2:0]=010, LIN mode status = {NE, RxBreakLength} MSEL[2:0]=011, Reserved; must be 00000 MSEL[2:0]=100, Reserved; must be 00000 MSEL[2:0]=101, Reserved; must be 00000 MSEL[2:0]=110, Reserved; must be 00000 MSEL[2:0]=111, LIN-UART hardware revision PS025016-1013 PRELIMINARY LIN-UART Z8 Encore! XP® F1680 Series Product Specification 169 Table 88. Mode Status Fields MULTIPROCESSOR Mode Status Field NEWFRM Status bit denoting the start of a new frame. Reading the LIN-UART Receive Data Register resets this bit to 0. 0 = The current byte is not the first data byte of a new frame. 1 = The current byte is the first data byte of a new frame. Multiprocessor Receive (MPRX) Returns the value of the last multiprocessor bit received. Reading from the LINUART Receive Data Register resets this bit to 0. Digital Noise Filter Mode Status Field Noise Event (NE); MSEL = 001b This bit is asserted if digital noise is detected on the receive data line when the data is sampled (center of bit-time). If this bit is set, it does not mean that the receive data is corrupted (though it can be in extreme cases), means that one or more of the noise filter data samples near the center of the bit-time did not match the average data value. LIN Mode Status Field Noise Event (NE); MSEL = 010b This bit is asserted if some noise level is detected on the receive data line when the data is sampled (center of bit-time). If this bit is set, it does not indicate that the receive data is corrupt (though it can be in extreme cases), means that one or more of the 16x data samples near the center of the bit-time did not match the average data value. RxBreakLength LIN mode received break length. This field can be read following a break (LIN Wake-up or Break) so that the software can determine the measured duration of the break. If the break exceeds 15 bit times the value saturates at 1111b. Hardware Revision Mode Status Field PS025016-1013 Noise Event (NE); MSEL = 111b This field indicates the hardware revision of the LIN-UART block. 00_xxx LIN UART hardware revision. 01_xxx Reserved. 10_xxx Reserved. 11_xxx Reserved. PRELIMINARY LIN-UART Z8 Encore! XP® F1680 Series Product Specification 170 12.3.5. LIN-UART Control 0 Register The LIN-UART Control 0 Register, shown in Table 89, configures the basic properties of LIN-UART’s transmit and receive operations. A more detailed discussion of each bit follows the table. Table 89. LIN-UART Control 0 Register (U0CTL0 = F42h) Bit 7 6 5 4 3 2 1 0 Field TEN REN CTSE PEN PSEL SBRK STOP LBEN Reset 0 0 0 0 0 0 0 0 R/W R/W R/W R/W R/W R/W R/W R/W R/W Address F42h, F4Ah Note: R/W = Read/Write. Bit Description [7] TEN Transmit Enable This bit enables or disables the transmitter. The enable is also controlled by the CTS signal and the CTSE bit. If the CTS signal is Low and the CTSE bit is 1, the transmitter is enabled. 0 = Transmitter disabled. 1 = Transmitter enabled. [6] REN Receive Enable This bit enables or disables the receiver. 0 = Receiver disabled. 1 = Receiver enabled. [5] CTSE Clear To Send Enable 0 = The CTS signal has no effect on the transmitter. 1 = The LIN-UART recognizes the CTS signal as an enable control for the transmitter. [4] PEN Parity Enable This bit enables or disables parity. Even or odd is determined by the PSEL bit. 0 = Parity is disabled. This bit is overridden by the MPEN bit. 1 = The transmitter sends data with an additional parity bit and the receiver receives an additional parity bit. [3] PSEL Parity Select 0 = Even parity is sent as an additional parity bit for the transmitter/receiver. 1 = Odd parity is sent as an additional parity bit for the transmitter/receiver. PS025016-1013 PRELIMINARY LIN-UART Z8 Encore! XP® F1680 Series Product Specification 171 Bit Description (Continued) [2] SBRK Send Break This bit pauses or breaks data transmission. Sending a break interrupts any transmission in progress, so ensure that the transmitter has completed sending data before setting this bit. In standard UART mode, the duration of the break is determined by how long the software leaves this bit asserted. Also the duration of any required stop bits following the break must be timed by software before writing a new byte to be transmitted to the Transmit Data Register. In LIN mode, the master sends a Break character by asserting SBRK. The duration of the break is timed by hardware and the SBRK bit is deasserted by hardware when the Break is completed. The duration of the Break is determined by the TxBreakLength field of the LIN Control Register. One or two stop bits are automatically provided by the hardware in LIN mode as defined by the stop bit. 0 = No break is sent. 1 = The output of the transmitter is 0. [1] STOP Stop Bit Select 0 = The transmitter sends one stop bit. 1 = The transmitter sends two stop bits. [0] LBEN Loop Back Enable 0 = Normal operation. 1 = All transmitted data is looped back to the receiver within the IrDA module. 12.3.6. LIN-UART Control 1 Registers Multiple registers, shown in Tables 90 and 91, are accessible by a single bus address. The register selected is determined by the Mode Select (MSEL) field. These registers provide additional control over LIN-UART operation. PS025016-1013 PRELIMINARY LIN-UART Z8 Encore! XP® F1680 Series Product Specification 172 12.3.6.1. Multiprocessor Control Register When MSEL = 000b, the Multiprocessor Control Register, shown in Table 90, provides control for UART MULTIPROCESSOR Mode, IRDA Mode and Baud Rate Timer Mode as well as other features that can apply to multiple modes. Table 90. Multiprocessor Control Register (U0CTL1 = F43h with MSEL = 000b) Bit 7 6 5 4 3 2 1 0 Field MPMD1 MPEN MPMD0 MPBT DEPOL BRGCTL RDAIRQ IREN Reset 0 0 0 0 0 0 0 0 R/W R/W R/W R/W R/W R/W R/W R/W R/W Address F43h, F4Bh Note: R/W = Read/Write. Bit Position Value Description [7,5] MPMD[1:0] MULTIPROCESSOR (9-bit) Mode [6] MPEN [4] MPBT [3] DEPOL PS025016-1013 00 The LIN-UART generates an interrupt request on all data and address bytes. 01 The LIN-UART generates an interrupt request only on received address bytes. 10 The LIN-UART generates an interrupt request when a received address byte matches the value stored in the Address Compare Register and on all successive data bytes until an address mismatch occurs. 11 The LIN-UART generates an interrupt request on all received data bytes for which the most recent address byte matched the value in the Address Compare Register. Multiprocessor Enable This bit is used to enable MULTIPROCESSOR (9-bit) Mode. 0 Disable MULTIPROCESSOR (9-bit) Mode. 1 Enable MULTIPROCESSOR (9-bit) Mode. Multiprocessor Bit Transmit This bit is applicable only when MULTIPROCESSOR (9-bit) Mode is enabled. 0 Send a 0 in the multiprocessor bit location of the data stream (9th bit). 1 Send a 1 in the multiprocessor bit location of the data stream (9th bit). Driver Enable Polarity 0 DE signal is active High. 1 DE signal is active Low. PRELIMINARY LIN-UART Z8 Encore! XP® F1680 Series Product Specification 173 Bit Position Value Description (Continued) [2] BRGCTL Baud Rate Generator Control This bit causes different LIN-UART behavior depending on whether the LIN-UART receiver is enabled (REN = 1 in the LIN-UART Control 0 Register). When the LINUART receiver is not enabled, this bit determines whether the Baud Rate Generator issues interrupts. When the LIN-UART receiver is enabled, this bit allows Reads from the baud rate registers to return the BRG count value instead of the reload value. Baud Rate Generator Control when the LIN-UART receiver is not enabled: 0 BRG is disabled. Reads from the Baud Rate High and Low Byte registers return the BRG reload value. 1 BRG is enabled and counting. The Baud Rate Generator generates a receive interrupt when it counts down to 0. Reads from the Baud Rate High and Low Byte registers return the current BRG count value. Baud Rate Generator Control when the LIN-UART receiver is enabled: [1] RDAIRQ [0] IREN PS025016-1013 0 Reads from the Baud Rate High and Low Byte registers return the BRG reload value. 1 Reads from the Baud Rate High and Low Byte registers return the current BRG count value. Unlike the timers, there is no mechanism to latch the High Byte when the Low Byte is read. Receive Data Interrupt 0 Received data and receiver errors generates an interrupt request to the Interrupt controller. 1 Received data does not generate an interrupt request to the Interrupt controller. Only receiver errors generate an interrupt request. Loop Back Enable 0 Infrared Encoder/Decoder is disabled. LIN-UART operates normally. 1 Infrared Encoder/Decoder is enabled. The LIN-UART transmits and receives data through the Infrared Encoder/Decoder. PRELIMINARY LIN-UART Z8 Encore! XP® F1680 Series Product Specification 174 12.3.7. Noise Filter Control Register When MSEL = 001b, the Noise Filter Control Register, shown in Table 91, provides control for the digital noise filter. Table 91. Noise Filter Control Register (U0CTL1 = F43h with MSEL = 001b) Bit 7 6 5 4 3 2 0 Field NFEN Reset 0 0 0 0 0 0 0 0 R/W R/W R/W R/W R R R R R/W NFCTL 1 — Address F43h, F4Bh Note: R = Read; R/W = Read/Write. Bit Position Value Description [7] NFEN Noise Filter Enable [6:4] NFCTL [3:0] Reserved PS025016-1013 0 Noise filter is disabled. 1 Noise filter is enabled. Receive data is preprocessed by the noise filter. Noise Filter Control This field controls the delay and noise rejection characteristics of the noise filter. The wider the counter is, the more delay is introduced by the filter and the wider the noise event is filtered. 000 4-bit up/down counter. 001 5-bit up/down counter. 010 6-bit up/down counter. 011 7-bit up/down counter. 100 8-bit up/down counter. 101 9-bit up/down counter. 110 10-bit up/down counter. 111 11-bit up/down counter. — Reserved; must be 0000. PRELIMINARY LIN-UART Z8 Encore! XP® F1680 Series Product Specification 175 12.3.8. LIN Control Register When MSEL = 010b, the LIN Control Register provides control for the LIN mode of operation. Table 92. LIN Control Register (U0CTL1 = F43h with MSEL = 010b) Bit 7 6 5 4 Field LMST LSLV ABEN ABIEN Reset 0 0 0 0 0 0 0 0 R/W R/W R/W R/W R/W R/W R/W R/W R/W Address 3 2 LinState[1:0] 1 0 TxBreakLength F43h, F4Bh Note: R/W = Read/Write. Bit Position Value Description [7] LMST LIN MASTER Mode [6] LSLV [5] ABEN [4] ABIEN PS025016-1013 0 LIN MASTER Mode not selected. 1 LIN MASTER Mode selected (if MPEN, PEN, LSLV = 0). LIN SLAVE Mode 0 LIN SLAVE Mode not selected. 1 LIN SLAVE Mode selected (if MPEN, PEN, LMST = 0). Autobaud Enable 0 Autobaud not enabled. 1 Autobaud enabled, if in LIN SLAVE Mode. Autobaud Interrupt Enable 0 Interrupt following autobaud does not occur. 1 Interrupt following autobaud enabled, if in LIN SLAVE Mode. When the autobaud character is received, a receive interrupt is generated and the ATB bit is set in the Status0 Register. PRELIMINARY LIN-UART Z8 Encore! XP® F1680 Series Product Specification 176 Bit Position Value Description (Continued) [3:2] LINSTATE[1:0] LIN State Machine The LinState is controlled by both hardware and software. Software can force a state change at any time if necessary. In normal operation, software moves the state in and out of Sleep state. For a LIN slave, software changes the state from Sleep to Wait for Break, after which hardware cycles through the Wait for Break, Autobaud and Active states. Software changes the state from one of the active states to Sleep state, if the LIN bus goes into Sleep mode. For a LIN master, software changes the state from Sleep to Active, where it remains until the software sets it back to the Sleep state. After configuration, software does not alter the LinState field during operation. [1:0] TxBreakLength PS025016-1013 00 Sleep state (either LMST or LSLV can be set). 01 Wait for Break state (only valid for LSLV = 1). 10 Autobaud state (only valid for LSLV = 1). 11 Active state (either LMST or LSLV can be set). TxBreakLength Used in LIN mode by the master to control the duration of the transmitted break. 00 13 bit times. 01 14 bit times. 10 15 bit times. 11 16 bit times. PRELIMINARY LIN-UART Z8 Encore! XP® F1680 Series Product Specification 177 12.3.9. LIN-UART Address Compare Register The LIN-UART Address Compare Register, shown in Table 93, stores the multinode network address of the LIN-UART. When the MPMD[1] bit of the LIN-UART Control Register 0 is set, all incoming address bytes are compared to the value stored in this Address Compare Register. Receive interrupts and RDA assertions only occur in the event of a match. Table 93. LIN-UART Address Compare Register (U0ADDR = F45h) Bit 7 6 5 Field 3 2 1 0 COMP_ADDR Reset R/W 4 0 0 0 0 0 0 0 0 R/W R/W R/W R/W R/W R/W R/W R/W Address F45h, F4Dh Note: R/W = Read/Write. Bit Position Value Description [7:0] COMP_ADDR — Compare Address This 8-bit value is compared to the incoming address bytes. 12.3.10. LIN-UART Baud Rate High and Low Byte Registers The LIN-UART Baud Rate High and Low Byte registers, shown in Tables 94 and 95) combine to create a 16-bit baud rate divisor value (BRG[15:0]) that sets the data transmission rate (baud rate) of the LIN-UART. Table 94. LIN-UART Baud Rate High Byte Register (U0BRH = F46h) Bit 7 6 5 4 Field 2 1 0 BRH Reset R/W 3 1 1 1 1 1 1 1 1 R/W R/W R/W R/W R/W R/W R/W R/W Address F46h, F4Eh Note: R/W = Read/Write. Bit Position Value Description [7:0] BRH — PS025016-1013 Baud Rate High These bits set the High byte of the baud rate divisor value. PRELIMINARY LIN-UART Z8 Encore! XP® F1680 Series Product Specification 178 Table 95. LIN-UART Baud Rate Low Byte Register (U0BRL = F47h) Bit 7 6 5 4 Field 3 2 1 0 BRL Reset R/W 1 1 1 1 1 1 1 1 R/W R/W R/W R/W R/W R/W R/W R/W Address F47h, F4Fh Note: R/W = Read/Write. Bit Position Value Description [7:0] BRL — Baud Rate Low These bits set the Low Byte of the baud rate divisor value. The LIN-UART data rate is calculated using the following equation for standard UART modes. For the LIN protocol, the Baud Rate registers must be programmed with the baud period rather than 1/16th of the baud period. Note: The UART must be disabled when updating the Baud Rate registers because the High and Low registers must be written independently. The LIN-UART data rate is calculated using the following equation for standard UART operation: UART Data Rate (bits/s) = System Clock Frequency (Hz) 16 x UART Baud Rate Divisor Value The LIN-UART data rate is calculated using the following equation for LIN mode UART operation: UART Data Rate (bits/s) = System Clock Frequency (Hz) UART Baud Rate Divisor Value For a given LIN-UART data rate, the integer baud rate divisor value is calculated using the following equation for standard UART operation: System Clock Frequency (Hz) UART Baud Rate Divisor Value (BRG) = Round  -------------------------------------------------------------------------------  16xUART Data Rate (bits/s)  PS025016-1013 PRELIMINARY LIN-UART Z8 Encore! XP® F1680 Series Product Specification 179 For a given LIN-UART data rate, the integer baud rate divisor value is calculated using the following equation for LIN mode UART operation: System Clock Frequency (Hz) UART Baud Rate Divisor Value (BRG) = Round  -------------------------------------------------------------------------------  UART Data Rate (bits/s)  The baud rate error relative to the appropriate baud rate is calculated using the following equation: ot Actual Data Rate – Desired Data Rate UART Baud Rate Error (%) = 100   ----------------------------------------------------------------------------------------------------   Desired Data Rate For reliable communication, the LIN-UART baud rate error must never exceed 5 percent. Tables 96 through 100 provide error data for popular baud rates and commonly-used crystal oscillator frequencies for normal UART modes of operation. Table 96. LIN-UART Baud Rates, 20.0 MHz System Clock Applicable Rate (kHz) BRG Divisor Actual Rate (Decimal) (kHz) Error (%) BRG Applicable Divisor Actual Rate Rate (kHz) (Decimal) (kHz) Error (%) 1250.0 1 1250.0 0.00 9.60 130 9.62 0.16 625.0 2 625.0 0.00 4.80 260 4.81 0.16 250.0 5 250.0 0.00 2.40 521 2.399 –0.03 115.2 11 113.64 –1.19 1.20 1042 1.199 –0.03 57.6 22 56.82 –1.36 0.60 2083 0.60 0.02 38.4 33 37.88 –1.36 0.30 4167 0.299 –0.01 19.2 65 19.23 0.16 Table 97. LIN-UART Baud Rates, 10.0 MHz System Clock BRG Applicable Divisor Actual Rate Rate (kHz) (Decimal) (kHz) Error (%) BRG Applicable Divisor Actual Rate Rate (kHz) (Decimal) (kHz) Error (%) 1250.0 N/A N/A N/A 9.60 65 9.62 0.16 625.0 1 625.0 0.00 4.80 130 4.81 0.16 250.0 3 208.33 –16.67 2.40 260 2.40 –0.03 115.2 5 125.0 8.51 1.20 521 1.20 –0.03 57.6 11 56.8 –1.36 0.60 1042 0.60 –0.03 PS025016-1013 PRELIMINARY LIN-UART Z8 Encore! XP® F1680 Series Product Specification 180 Table 97. LIN-UART Baud Rates, 10.0 MHz System Clock (Continued) BRG Applicable Divisor Actual Rate Rate (kHz) (Decimal) (kHz) Error (%) 38.4 16 39.1 1.73 19.2 33 18.9 0.16 BRG Applicable Divisor Actual Rate Rate (kHz) (Decimal) (kHz) Error (%) 0.30 2083 0.30 0.2 Table 98. LIN-UART Baud Rates, 5.5296 MHz System Clock BRG Applicable Divisor Actual Rate Rate (kHz) (Decimal) (kHz) Error (%) BRG Applicable Divisor Actual Rate Rate (kHz) (Decimal) (kHz) Error (%) 1250.0 N/A N/A N/A 9.60 36 9.60 0.00 625.0 N/A N/A N/A 4.80 72 4.80 0.00 250.0 1 345.6 38.24 2.40 144 2.40 0.00 115.2 3 115.2 0.00 1.20 288 1.20 0.00 57.6 6 57.6 0.00 0.60 576 0.60 0.00 38.4 9 38.4 0.00 0.30 1152 0.30 0.00 19.2 18 19.2 0.00 Table 99. LIN-UART Baud Rates, 3.579545 MHz System Clock BRG Applicable Divisor Actual Rate (kHz) Error (%) Rate (kHz) (Decimal) BRG Divisor Actual Rate Applicable Rate (kHz) (Decimal) (kHz) Error (%) 1250.0 N/A N/A N/A 9.60 23 9.73 1.32 625.0 N/A N/A N/A 4.80 47 4.76 –0.83 250.0 1 223.72 –10.51 2.40 93 2.41 0.23 115.2 2 111.9 –2.90 1.20 186 1.20 0.23 57.6 4 55.9 –2.90 0.60 373 0.60 –0.04 38.4 6 37.3 –2.90 0.30 746 0.30 –0.04 19.2 12 18.6 –2.90 PS025016-1013 PRELIMINARY LIN-UART Z8 Encore! XP® F1680 Series Product Specification 181 Table 100. LIN-UART Baud Rates, 1.8432 MHz System Clock BRG Applicable Divisor Actual Rate Rate (kHz) (Decimal) (kHz) Error(%) BRG Applicable Divisor Actual Rate Rate (kHz) (Decimal) (kHz) Error(%) 1250.0 N/A N/A N/A 9.60 12 9.60 0.00 625.0 N/A N/A N/A 4.80 24 4.80 0.00 250.0 N/A N/A N/A 2.40 48 2.40 0.00 115.2 1 115.2 0.00 1.20 96 1.20 0.00 57.6 2 57.6 0.00 0.60 192 0.60 0.00 38.4 3 38.4 0.00 0.30 384 0.30 0.00 19.2 6 19.2 0.00 PS025016-1013 PRELIMINARY LIN-UART Z8 Encore! XP® F1680 Series Product Specification 182 Chapter 13. Infrared Encoder/Decoder The Z8 Encore! XP F1680 Series products contain a fully-functional, high-performance UART to infrared encoder/decoder (endec). The infrared endec is integrated with an onchip UART to allow easy communication between the Z8 Encore! and IrDA Physical Layer Specification and version 1.3-compliant infrared transceivers. Infrared communication provides secure, reliable, low-cost, point-to-point communication between PCs, PDAs, cell phones, printers and other infrared enabled devices. 13.1. Architecture Figure 27 displays the architecture of the infrared endec. System Clock Infrared Transceiver RxD RXD RXD TxD UART Baud Rate Clock Interrupt I/O Signal Address Infrared Encoder/Decoder (endec) TXD TXD Data Figure 27. Infrared Data Communication System Block Diagram 13.2. Operation When the infrared endec is enabled, the transmit data from the associated on-chip UART is encoded as digital signals in accordance with the IrDA standard and output to the infrared transceiver through the TXD pin. Likewise, data received from the infrared transceiver is passed to the infrared endec through the RXD pin, decoded by the infrared PS025016-1013 PRELIMINARY Infrared Encoder/Decoder Z8 Encore! XP® F1680 Series Product Specification 183 endec and passed to the UART. Communication is half-duplex, that is, simultaneous data transmission and reception is not allowed. The baud rate is set by the UART’s Baud Rate Generator and supports IrDA standard baud rates from 9600 baud to 115.2 KBaud. Higher baud rates are possible, but do not meet IrDA specifications. The UART must be enabled to use the infrared endec. The infrared endec data rate is calculated using the following equation: System Clock Frequency  Hz  Infrared Data Rate  bits  s  = -----------------------------------------------------------------------------------------------------16  UART Baud Rate Divisor Value 13.2.1. Transmitting IrDA Data The data to be transmitted using the infrared transceiver is first sent to the UART. The UART’s transmit signal (TXD) and baud rate clock are used by the IrDA to generate the modulation signal (IR_TXD) that drives the infrared transceiver. Each UART/infrared data bit is 16 clocks wide. If the data to be transmitted is 1, the IR_TXD signal remains Low for the full 16-clock period. If the data to be transmitted is 0, the transmitter first outputs a 7-clock Low period, followed by a 3-clock High pulse. Finally, a 6-clock Low pulse is the output to complete the full 16 clock data period. Figure 28 displays IrDA data transmission. When the infrared endec is enabled, the UART’s TXD signal is internal to the Z8 Encore! XP F1680 Series products while the IR_TXD signal is the output through the TXD pin. 16-clock period Baud Rate Clock UART’s TXD Start Bit = 0 Data Bit 0 = 1 Data Bit 1 = 0 Data Bit 2 = 1 Data Bit 3 = 1 3-clock pulse IR_TXD 7-clock delay Figure 28. Infrared Data Transmission PS025016-1013 PRELIMINARY Infrared Encoder/Decoder Z8 Encore! XP® F1680 Series Product Specification 184 13.2.2. Receiving IrDA Data Data received from the infrared transceiver using the IR_RXD signal through the RXD pin is decoded by the infrared endec and passed to the UART. The UART’s baud rate clock is used by the infrared endec to generate the demodulated signal (RXD) that drives the UART. Each UART/infrared data bit is 16 clocks wide. Figure 29 displays data reception. When the infrared endec is enabled, the UART’s RXD signal is internal to the Z8 Encore! XP F1680 Series products while the IR_RXD signal is received through the RXD pin. 16-clock period Baud Rate Clock Start Bit = 0 Data Bit 0 = 1 Data Bit 1 = 0 Data Bit 2 = 1 Data Bit 3 = 1 IR_RXD min. 1.4 µs pulse UART’s RXD Start Bit = 0 8-clock delay 16-clock period Data Bit 0 = 1 Data Bit 1 = 0 16-clock period 16-clock period Data Bit 2 = 1 Data Bit 3 = 1 16-clock period Figure 29. IrDA Data Reception Caution: The system clock frequency must be at least 1.0 MHz to ensure proper reception of the 1.4 µs minimum width pulses allowed by the IrDA standard. 13.2.2.1. Endec Receiver Synchronization The IrDA receiver uses a local baud rate clock counter (0 to 15 clock periods) to generate an input stream for the UART and to create a sampling window for detection of incoming pulses. The generated UART input (UART RXD) is delayed by 8 baud rate clock periods with respect to the incoming IrDA data stream. When a falling edge in the input data stream is detected, the endec counter is reset. When the count reaches a value of 8, the UART RXD value is updated to reflect the value of the decoded data. When the count reaches 12 baud clock periods, the sampling window for the next incoming pulse opens. PS025016-1013 PRELIMINARY Infrared Encoder/Decoder Z8 Encore! XP® F1680 Series Product Specification 185 The window remains open until the count again reaches 8 (in other words, 24 baud clock periods since the previous pulse is detected), giving the endec a sampling window of minus 4 baud rate clocks to plus 8 baud rate clocks around the expected time of an incoming pulse. If an incoming pulse is detected inside this window this process is repeated. If the incoming data is a logical 1 (no pulse), the endec returns to the initial state and waits for the next falling edge. As each falling edge is detected, the endec clock counter is reset, resynchronizing the endec to the incoming signal, allowing the endec to tolerate jitter and baud rate errors in the incoming datastream. Resynchronizing the endec does not alter the operation of the UART, which ultimately receives the data. The UART is only synchronized to the incoming data stream when a start bit is received. 13.3. Infrared Encoder/Decoder Control Register Definitions All infrared endec configuration and status information is set by the UART control registers as defined beginning on page 163. Caution: To prevent spurious signals during IrDA data transmission, set the IREN bit in the UART Control 1 Register to 1 to enable the infrared encoder/decoder before enabling the GPIO Port alternate function for the corresponding pin of UART. See Tables 17 through 19 on pages 49–54 for details. PS025016-1013 PRELIMINARY Infrared Encoder/Decoder Z8 Encore! XP® F1680 Series Product Specification 186 Chapter 14. Analog-to-Digital Converter The Z8 Encore! includes an eight-channel Successive Approximation Register Analog-toDigital converter (SAR ADC). The ADC converts an analog input signal to a 10-bit binary number. The features of the ADC include: • • • • • • • Eight analog input sources multiplexed with general-purpose I/O ports Fast conversion time, less than 4.9 µs Programmable timing controls Interrupt on conversion complete Internal 1.6 V voltage reference generator Internal reference voltage available externally Ability to supply external reference voltage 14.1. Architecture The ADC architecture, shown in Figure 30, consists of an 8-input multiplexer, sampleand-hold amplifier and 10-bit SAR ADC. The ADC digitizes the signal on a selected channel and stores the digitized data in the ADC data registers. In environments with high electrical noise, an external RC filter must be added at the input pins to reduce highfrequency noise. 14.2. Operation The ADC converts the analog input, ANAX, to a 10-bit digital representation. The equation for calculating the digital value is calculated by: ADC Output = 1024   ANA x  V REF  Assuming zero gain and offset errors, any voltage outside the ADC input limits of AVSS and VREF returns all 0s or 1s, respectively. A new conversion can be initiated by software write to the ADC Control Register’s start bit. Initiating a new conversion stops any conversion currently in progress and begins a new conversion. To avoid disrupting a conversion already in progress, this start bit can be read to indicate ADC operation status (busy or available). PS025016-1013 PRELIMINARY Analog-to-Digital Converter Z8 Encore! XP® F1680 Series Product Specification 187 REFEN Sel 28 Package VR2 Internal Voltage Reference Generator VREF RBUF Analog Input Multiplexer Analog-to-Digital Converter ANA0 ANA1 Reference Input Data Output 10 BUSY ANA2 ANA3 Analog Input Sample-and-Hold Amplifier ANA4 ANA5 ANA6 ANA7 ADCLK ANAIN[2:0] ADCEN SAMPLE/HOLD START Figure 30. Analog-to-Digital Converter Block Diagram 14.2.1. ADC Timing Each ADC measurement consists of 3 phases: 1. Input sampling (programmable, minimum of 1.8 µs). 2. Sample-and-hold amplifier settling (programmable, minimum of 0.5 µs). 3. Conversion is 13 ADCLK cycles. Figure 31 displays the timing of an ADC conversion. PS025016-1013 PRELIMINARY Analog-to-Digital Converter Z8 Encore! XP® F1680 Series Product Specification 188 conversion period START 1.8 µs min sample period Programmable settling period SAMPLE/HOLD 13-clock convert period BUSY Figure 31. ADC Timing Diagram 14.2.2. ADC Interrupt convertbit7 convertbit6 convertbit5 convertbit4 convertbit3 4 5 6 7 8 9 store in register convertbit8 3 convertbit0 convertbitmsb 2 convertbit1 sync 1 convertbit2 sync The ADC can generate an interrupt request when a conversion is completed. An interrupt request that is pending when the ADC is disabled is not automatically cleared. See Figure 32. 10 11 12 13 14 15 16 17 ADC Clock BUSY 13 clocks convert period Figure 32. ADC Convert Timing 14.2.3. Reference Buffer The reference buffer, RBUF, supplies the reference voltage for the ADC. When enabled, the internal voltage reference generator supplies the ADC and this voltage is available on PS025016-1013 PRELIMINARY Analog-to-Digital Converter Z8 Encore! XP® F1680 Series Product Specification 189 the VREF pin. When RBUF is disabled, the ADC must have the reference voltage supplied externally through the VREF pin. RBUF is controlled by the REFEN bit in the ADC Control Register. 14.2.4. Internal Voltage Reference Generator The Internal Voltage Reference Generator provides the voltage, VR2, for the RBUF. VR2 is 1.6 V. 14.2.5. Calibration and Compensation You can calibrate and store the values into Flash, or the user code can perform a manual offset calibration. There is no provision for manual gain calibration. 14.3. ADC Control Register Definitions The registers that control analog-to-digital conversion functions are defined in this section. 14.3.1. ADC Control Register 0 The ADC Control Register 0, shown in Table 101, initiates the A/D conversion and provides ADC status information. Table 101. ADC Control Register 0 (ADCCTL0) Bits 7 6 5 4 Field START INTREF_SEL REFEN ADCEN Reset 0 0 0 0 0 0 0 0 R/W1 R/W R/W R/W R/W R/W R/W R/W R/W Address 3 2 1 ANAIN[3:0] F70h Bit Position Value (H) Description [7] START  0 ADC Start/Busy Writing a 0 has no effect. Reading a 0 indicates the ADC is available to begin a conversion. 1 Writing a 1 starts a conversion. Reading a 1 indicates that a conversion is currently in progress. 0 Select 1.6 V as internal reference. 1 Select AVDD as internal reference. [6] INTREF_SEL PS025016-1013 0 PRELIMINARY Analog-to-Digital Converter Z8 Encore! XP® F1680 Series Product Specification 190 Bit Position Value (H) Description (Continued) [5] REFEN 0 Select external reference. 1 Select internal reference. [4] ADCEN 0 ADC is disabled. 1 ADC is enabled for normal use. This bit cannot change with bit 7 (start) at the same time. [3:0] ANAIN  0000 Analog Input Select ANA0 input is selected for analog-to-digital conversion. 0001 ANA1 input is selected for analog-to-digital conversion. 0010 ANA2 input is selected for analog-to-digital conversion. 0011 ANA3 input is selected for analog-to-digital conversion. 0100 ANA4 input is selected for analog-to-digital conversion. 0101 ANA5 input is selected for analog-to-digital conversion. 0110 ANA6 input is selected for analog-to-digital conversion. 0111 ANA7 input is selected for analog-to-digital conversion. 1000 Hold LPO input nodes (ANA1 and ANA2) to ground. 1001 Temperature Sensor. 1100 Temperature Sensor output to ANA3 PAD. 1101 vbg_chop signal output to ANA3 PAD. Others Reserved. PS025016-1013 PRELIMINARY Analog-to-Digital Converter Z8 Encore! XP® F1680 Series Product Specification 191 14.3.2. ADC Raw Data High Byte Register The ADC Raw Data High Byte Register, shown in Table 102, contains the upper 8 bits of raw data from the ADC output. Access to the ADC Raw Data High Byte register is readonly. This register is used for test only. Table 102. ADC Raw Data High Byte Register (ADCRD_H) Bits 7 6 5 4 3 Field ADCRDh Reset X R/W R Address 2 1 0 F71h Value (H) Description Bit Position [7:0] 00–FF ADC Raw Data High Byte The data in this register is the raw data coming from the SAR Block. It will change as the conversion is in progress. This register is used for testing only. 14.3.3. ADC Data High Byte Register The ADC Data High Byte Register, shown in Table 103, contains the upper eight bits of the ADC output. Access to the ADC Data High Byte Register is read-only. Reading the ADC Data High Byte Register latches data in the ADC Low Bits Register. Table 103. ADC Data High Byte Register (ADCD_H) Bits 7 6 5 4 3 Field ADCDh Reset X R/W R Address Bit Position [7:0] PS025016-1013 2 1 0 F72h Value (H) Description 00–FF ADC High Byte The last conversion output is held in the data registers until the next ADC conversion has completed. PRELIMINARY Analog-to-Digital Converter Z8 Encore! XP® F1680 Series Product Specification 192 14.3.4. ADC Data Low Bits Register The ADC Data Low Bits Register, shown in Table 104, contains the lower bits of the ADC output as well as an overflow status bit. Access to the ADC Data Low Bits Register is read-only. Reading the ADC Data High Byte Register latches data in the ADC Low Bits Register. Table 104. ADC Data Low Bits Register (ADCD_L) Bits 7 6 5 4 3 2 Field ADCDL Reserved Reset X X R/W R R Address 1 0 F73h Bit Position Value Description (H) [7:6] ADCDL 00– 11b ADC Low Bit These bits are the 2 least significant bits of the 10-bit ADC output; they are undefined after a Reset. The Low bits are latched into this register whenever the ADC Data High Byte register is read. [5:0] 0 Reserved; must be 0. PS025016-1013 PRELIMINARY Analog-to-Digital Converter Z8 Encore! XP® F1680 Series Product Specification 193 14.3.5. Sample Settling Time Register The Sample Settling Time Register, shown in Table 105, is used to program the length of time from the SAMPLE/HOLD signal to the start signal, when the conversion can begin. The number of clock cycles required for settling will vary from system to system depending on the system clock period used. The system designer should program this register to contain the number of clocks required to meet a 0.5 µs minimum settling time. Table 105. Sample Settling Time (ADCSST) Bits 7 6 5 Field Reserved Reset 0 R/W R 4 3 2 1 0 1 1 SST 1 1 R/W Address F74h Bit Position Value Description (H) [7:4] 0 Reserved; must be 0. [3:0] SST 0–F Sample settling time in number of system clock periods to meet 0.5 µs minimum. PS025016-1013 PRELIMINARY Analog-to-Digital Converter Z8 Encore! XP® F1680 Series Product Specification 194 14.3.6. Sample Time Register The Sample Time Register, shown in Table 106, is used to program the length of active time for the sample after a conversion begins by setting the start bit in the ADC Control Register or initiated by the PWM. The number of system clock cycles required for sample time varies from system to system, depending on the clock period used. The system designer should program this register to contain the number of system clocks required to meet a 1.8 µs minimum sample time. Table 106. Sample Time (ADCST) Bits 7 6 Field Reserved Reset 0 R/W 5 4 3 2 1 0 1 1 1 ST 1 1 1 R/W R/W Address F75h Bit Position Value (H) Description [7:6] 0 Reserved; must be 0. [5:0] ST 00–3F Sample Hold time in number of system clock periods to meet 1.8 µs minimum. PS025016-1013 PRELIMINARY Analog-to-Digital Converter Z8 Encore! XP® F1680 Series Product Specification 195 14.3.7. ADC Clock Prescale Register The ADC Clock Prescale Register, shown in Table 107, is used to provide a divided system clock to the ADC. When this register is programmed with 0h, the System Clock is used for the ADC Clock. DIV16 maintains the highest priority, DIV2 has the lowest priority. Table 107. ADC Clock Prescale Register (ADCCP) Bits 7 6 5 4 3 2 1 0 Field Reserved DIV16 DIV8 DIV4 DIV2 Reset 0 0 0 0 0 R/W R/W Address F76h Bit Description [7:4] Reserved; must be 0. [3] DIV16 Divide by 16 0 = Clock is not divided. 1 = System Clock is divided by 16 for ADC Clock. [2] DIV8 Divide by 8 0 = Clock is not divided. 1 = System Clock is divided by 8 for ADC Clock. [1] DIV4 Divide by 4 0 = Clock is not divided. 1 = System Clock is divided by 4 for ADC Clock. [0] DIV2 Divide by 2 0 = Clock is not divided. 1 = System Clock is divided by 2 for ADC Clock. Caution: The maximum ADC clock at 2.7 V–3.6 V is 5 MHz. The maximum ADC clock at 1.8 V– 2.7 V is 2.5 MHz. Set the Prescale Register correctly according to the different system clocks. See the ADC Clock Prescale Register for details. PS025016-1013 PRELIMINARY Analog-to-Digital Converter Z8 Encore! XP® F1680 Series Product Specification 196 Chapter 15. Low-Power Operational Amplifier The low-power operational amplifier is a standard operational amplifier designed for current measurements. Each of the three ports of the amplifier is accessible from the package pins. The inverting input is commonly used to connect to the current source. The output node connects an external feedback network to the inverting input. The noninverting output is required to apply a nonzero bias point. In a standard single-supply system, this bias point must be substantially above ground to measure positive input currents. The noninverting input can also be used for offset correction. Note: This amplifier is a voltage gain operational amplifier. Its transimpedance nature is determined by the feedback network. The low-power operational amplifier contains only one pin configuration; ANA0 is the output/feedback node, ANA1 is the inverting input and ANA2 is the noninverting input. To use the low-power operational amplifier, it must be enabled in the Power Control Register Definitions, discussed on page 44. The default state of the low-power operational amplifier is OFF. To use the low-power operational amplifier, the TRAM bit must be cleared, turning it ON (see Power Control Register 0 on page 44). When making normal ADC (i.e., not transimpedance) measurements on ANA0, the TRAM bit must be OFF. Turning the TRAM bit ON interferes with normal ADC measurements. Finally, this bit enables the amplifier even in STOP Mode. If the amplifier is not required in STOP Mode, disable it. Failing to perform this results in STOP Mode currents greater than specified. As with other ADC measurements, any pins used for analog purposes must be configured as in the GPIO registers (see the Port A–E Alternate Function Subregisters on page 61). Standard transimpedance measurements are made on ANA0 as selected by the ANAIN[3:0] bits of the ADC Control Register 0, discussed on page 189. It is also possible to make single-ended measurements on ANA1 and ANA2 when the amplifier is enabled which is often useful for determining offset conditions. PS025016-1013 PRELIMINARY Low-Power Operational Amplifier Z8 Encore! XP® F1680 Series Product Specification 197 Chapter 16. Enhanced Serial Peripheral Interface The Enhanced Serial Peripheral Interface (ESPI) supports the Serial Peripheral Interface (SPI) and other synchronous serial interface modes, such as Inter-IC Sound (I2S) and time division multiplexing (TDM). ESPI includes the following features: • • • • Full-duplex, synchronous, character-oriented communication • SLAVE Mode transfer rates up to a maximum of one-eighth the system clock frequency • • • Error detection Four-wire interface (SS, SCK, MOSI and MISO) Data Shift Register is buffered to enable high throughput MASTER Mode transfer rates up to a maximum of one-half the system clock frequency Dedicated Programmable Baud Rate Generator Data transfer control via polling, interrupt 16.1. Architecture The ESPI is a full-duplex, synchronous, character-oriented channel that supports a fourwire interface (serial clock, transmit data, receive data and slave select). The ESPI block consists of a shift register, data buffer register, a Baud Rate (clock) Generator, control/ status registers and a control state machine. Transmit and receive transfers are in synch as there is a single shift register for both transmitting and receiving data. Figure 33 displays a diagram of the ESPI block. PS025016-1013 PRELIMINARY Enhanced Serial Peripheral Interface Z8 Encore! XP® F1680 Series Product Specification 198 Peripheral Bus Interrupt ESPI Control Register ESPI Status Register ESPI BRH Register ESPI Mode Register ESPI State Register ESPI BRL Register ESPI State Machine Baud Rate Generator Interrupt count = 1 Data Register SCK Logic Shift Register 0 1 2 3 4 5 6 7 data_out SS out SCK in SS in MISO in MOSI in Pin Direction Control MISO out SCK out MOSI out GPIO Logic and Port Pins SS MISO MOSI SCK Figure 33. ESPI Block Diagram PS025016-1013 PRELIMINARY Enhanced Serial Peripheral Interface Z8 Encore! XP® F1680 Series Product Specification 199 16.2. ESPI Signals The four ESPI signals are: • • • • Master-In/Slave-Out (MISO) Master-Out/Slave-In (MOSI) Serial Clock (SCK) Slave Select (SS) The following paragraphs discuss these signals as they operate in both MASTER and SLAVE modes. 16.2.1. Master-In/Slave-Out The Master-In/Slave-Out (MISO) pin is configured as an input in a Master device and as an output in a slave device. Data is transferred most significant bit first. The MISO pin of a Slave device is placed in a high-impedance state if the Slave is not selected. When the ESPI is not enabled, this signal is in a high-impedance state. The direction of this pin is controlled by the MMEN bit of the ESPI Control Register. 16.2.2. Master-Out/Slave-In The Master-Out/Slave-In (MOSI) pin is configured as an output in a Master device and as an input in a slave device. Data is transferred most significant bit first. When the ESPI is not enabled, this signal is in a high-impedance state. The direction of this pin is controlled by the MMEN bit of the ESPI Control Register. 16.2.3. Serial Clock The Serial Clock (SCK) synchronizes data movement both in and out of the Shift Register via the MOSI and MISO pins. In MASTER Mode (MMEN = 1), the ESPI’s Baud Rate Generator creates the serial clock and drives it out on its SCK pin to the slave devices. In SLAVE Mode, the SCK pin is an input. Slave devices ignore the SCK signal, unless their SS pin is asserted. The Master and Slave are each capable of exchanging a character of data during a sequence of NUMBITS clock cycles (see Table 112 on page 217). In both Master and Slave ESPI devices, data is shifted on one edge of the SCK and is sampled on the opposite edge where data is stable. SCK phase and polarity is determined by the PHASE and CLKPOL bits in the ESPI Control Register. PS025016-1013 PRELIMINARY Enhanced Serial Peripheral Interface Z8 Encore! XP® F1680 Series Product Specification 200 16.2.4. Slave Select The Slave Select signal is a bidirectional framing signal with several modes of operation to support SPI and other synchronous serial interface protocols. The Slave Select mode is selected by the SSMD field of the ESPI Mode Register. The direction of the SS signal is controlled by the SSIO bit of the ESPI Mode Register. The SS signal is an input on slave devices and is an output on the active Master device. Slave devices ignore transactions on the bus unless their Slave Select input is asserted. In SPI MASTER Mode, additional GPIO pins are required to provide Slave Selects if there is more than one slave device. 16.3. Operation During a transfer, data is sent and received simultaneously by both the Master and Slave devices. Separate signals are required for transmit data, receive data and the serial clock. When a transfer occurs, a multi-bit (typically 8-bit) character is shifted out one data pin and a multi-bit character is simultaneously shifted in on second data pin. An 8-bit shift register in the Master and an 8-bit shift register in the Slave are connected as a circular buffer. The ESPI Shift Register is buffered to support back-to-back character transfers in high-performance applications. A transaction is initiated when the Data Register is written in the Master device. The value from the Data Register is transferred into the Shift Register and the SPI transaction begins. At the end of each character transfer, if the next transmit value has been written to the Data Register, the data and shift register values are swapped, which places the new transmit data into the Shift Register and the Shift Register contents (receive data) into the Data Register. At that point the Receive Data Register Not Empty signal is asserted (RDRNE bit set in the Status Register). After software reads the receive data from the Data Register, the Transmit Data Register Empty signal is asserted (TDRE bit set in the Status Register) to request the next transmit byte. To support back-to-back transfers without an intervening pause, the receive and transmit interrupts must be serviced when the current character is being transferred. The Master sources the Serial Clock (SCK) and Slave Select signal (SS) during the transfer. Internal data movement (by software) to/from the ESPI block is controlled by the Transmit Data Register Empty (TDRE) and Receive Data Register Not Empty (RDRNE) signals. These signals are read-only bits in the ESPI Status Register. When either the TDRE or RDRNE bits assert, an interrupt is sent to the interrupt controller. In many cases the software application is only moving information in one direction. In this case either the TDRE or RDRNE interrupts can be disabled to minimize software overhead. Unidirectional data transfer is supported by setting the ESPIEN1,0 bits in the Control Register to 10 or 01. PS025016-1013 PRELIMINARY Enhanced Serial Peripheral Interface Z8 Encore! XP® F1680 Series Product Specification 201 16.3.1. Throughput In MASTER Mode, the maximum SCK rate supported is one-half the system clock frequency. This rate is achieved by programming the value 0001h into the Baud Rate High/Low register pair. Though each character will be transferred at this rate it is unlikely that software interrupt routines could keep up with this rate. In SPI mode the transfer will automatically pause between characters until the current receive character is read and the next transmit data value is written. In SLAVE Mode, the transfer rate is controlled by the Master. As long as the TDRE and RDRNE interrupt are serviced before the next character transfer completes, the Slave will keep up with the Master. In SLAVE Mode the baud rate must be restricted to a maximum of one-eighth of the system clock frequency to allow for synchronization of the SCK input to the internal system clock. 16.3.2. ESPI Clock Phase and Polarity Control The ESPI supports four combinations of serial clock phase and polarity using two bits in the ESPI Control Register. The clock polarity bit, CLKPOL, selects an active High or active Low clock and has no effect on the transfer format. Table 108 lists the ESPI Clock Phase and Polarity Operation parameters. The clock phase bit, PHASE, selects one of two fundamentally different transfer formats. The data is output a half-cycle before the receive clock edge which provides a half cycle of setup and hold time. Table 108. ESPI Clock Phase (PHASE) and Clock Polarity (CLKPOL) Operation PHASE CLKPOL SCK Transmit Edge SCK Receive Edge SCK Idle State 0 0 Falling Rising Low 0 1 Rising Falling High 1 0 Rising Falling Low 1 1 Falling Rising High 16.3.2.1. Transfer Format when Phase Equals Zero Figure 34 displays the timing diagram for an SPI type transfer, in which PHASE = 0. For SPI transfers the clock only toggles during the character transfer. The two SCK waveforms show polarity with CLKPOL = 0 and CLKPOL = 1. The diagram can be interpreted as either a Master or Slave timing diagram because the SCK Master-In/SlaveOut (MISO) and Master-Out/Slave-In (MOSI) pins are directly connected between the Master and the Slave. PS025016-1013 PRELIMINARY Enhanced Serial Peripheral Interface Z8 Encore! XP® F1680 Series Product Specification 202 SCK (CLKPOL = 0) SCK (CLKPOL = 1) MOSI Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 MISO Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 Input Sample Time SS Figure 34. ESPI Timing when PHASE = 0 16.3.2.2. Transfer Format When Phase Equals One Figure 35 displays a timing diagram for an SPI type transfer in which PHASE is one. For SPI transfers the clock only toggles during the character transfer. Two waveforms are depicted for SCK, one for CLKPOL = 0 and another for CLKPOL = 1. PS025016-1013 PRELIMINARY Enhanced Serial Peripheral Interface Z8 Encore! XP® F1680 Series Product Specification 203 SCK (CLKPOL = 0) SCK (CLKPOL = 1) MOSI Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 MISO Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 Bit0 Input Sample Time SS Figure 35. ESPI Timing when PHASE = 1 16.3.3. Slave Select Modes of Operation This section describes the different modes of data transfer supported by the ESPI block. The mode is selected by the Slave Select Mode (SSMD) field of the Mode Register. 16.3.3.1. SPI Mode This mode is selected by setting the SSMD field of the Mode Register to 00. In this mode software controls the assertion of the SS signal directly via the SSV bit of the SPI Transmit Data Command register. Software can be used to control an SPI mode transaction. Prior to or simultaneously with writing the first transmit data byte; software sets the SSV bit. Software sets the SSV bit either by performing a byte write to the Transmit Data Command register prior to writing the first transmit character to the Data Register or by performing a word write to the Data Register address which loads the first transmit character and simultaneously sets the SSV bit. SS will remain asserted when one or more characters are transferred. There are two mechanisms for deasserting SS at the end of the transaction. One method used by software is to set the TEOF bit of the Transmit Data Command register, when the last TDRE interrupt is being serviced (set TEOF before or simultaneously with writing the last data byte). After the last bit of the last character is PS025016-1013 PRELIMINARY Enhanced Serial Peripheral Interface Z8 Encore! XP® F1680 Series Product Specification 204 transmitted, the hardware will automatically deassert the SSV and TEOF bits. The second method is for software to directly clear the SSV bit after the transaction completes. If software clears the SSV bit directly it is not necessary for software to also set the TEOF bit on the last transmit byte. After writing the last transmit byte, the end of the transaction can be detected by waiting for the last RDRNE interrupt or monitoring the TFST bit in the ESPI Status Register. The transmit underrun and receive overrun errors will not occur in an SPI mode Master. If the RDRNE and TDRE requests have not been serviced before the current byte transfer completes, SCLK will be paused until the Data Register is read and written. The transmit underrun and receive overrun errors will occur in a Slave if the Slave’s software does not keep up with the Master data rate. In this case the Shift Register in the Slave will be loaded with all 1s. In the SPI mode, the SCK is active only for the data transfer with one SCK period per bit transferred. If the SPI bus has multiple Slaves, the Slave Select lines to all or all but one of the Slaves must be controlled independently by software using GPIO pins. Figure 36 displays multiple character transfer in SPI mode. Note: PS025016-1013 When character n is transferred via the Shift Register, software responds to the receive request for character n-1 and the transmit request for character n+1. PRELIMINARY Enhanced Serial Peripheral Interface Z8 Encore! XP® F1680 Series Product Specification 205 SCK (SSMD = 00, PHASE = 0, CLKPOL = 0, SSPO = 0) MOSI, MISO Data Register Shift Register Bit0 Bit7 Tx n Rx n-1 Tx/Rx n-1 Bit6 Bit1 empty Bit0 Bit7 Rx n Tx n+1 Tx/Rx n Bit 6 empty Tx/Rx n+1 TDRE RDRNE ESPI Interrupt Figure 36. SPI Mode (SSMD = 00) 16.3.3.2. Synchronous Frame Sync Pulse Mode This mode is selected by setting the SSMD field of the Mode Register to 10. This mode is typically used for continuous transfer of fixed length frames where the frames are delineated by a pulse of duration one SCK period. The SSV bit in the ESPI Transmit Data Command register does not control the SS pin directly in this mode. SSV must be set before or in sync with the first transmit data byte being written. The SS signal will assert 1 SCK cycle before the first data bit and will stop after 1 SCK period. SCK is active from the initial assertion of SS until the transaction end due to lack of transmit data. The transaction is terminated by the Master when it no longer has data to send. If TDRE=1 at the end of a character, the SS output will remain detached and SCK stops after the last bit is transferred. The TUND bit (transmit underrun) will assert in this case. After the transaction has completed, hardware will clear the SSV bit. Figure 37 displays a frame with synchronous frame sync pulse mode. PS025016-1013 PRELIMINARY Enhanced Serial Peripheral Interface Z8 Encore! XP® F1680 Series Product Specification 206 SCK (SSMD = 10, PHASE = 0, CLKPOL = 0, SSPO = 1) MOSI, MISO Bit7 Bit6 Bit1 Bit0 Bit7 Bit 6 SS SSV Figure 37. Synchronous Frame Sync Pulse mode (SSMD = 10) 16.3.3.3. Synchronous Framing with SS Mode This mode is selected by setting the SSMD field of the Mode Register to 11. Figure 38 displays synchronous message framing mode with SS alternating between consecutive frames. A frame consists of a fixed number of data bytes as defined by software. An example of this mode is the Inter-IC Sound (I2S) protocol which is used to transfer left/ right channel audio data. The SSV indicates whether the corresponding bytes are left or right channel data. The SSV value must be updated when servicing the TDRE interrupt/ request for the first byte in a left or write channel frame. This can be accomplished by performing a word write when writing the first byte of the audio word, which will update both the ESPI Data and Transmit Data Command words or by doing a byte write to update SSV followed by a byte Write to the Data Register. The SS signal will lead the data by one SCK period. The transaction is terminated when the Master has no more data to transmit. After the last bit is transferred, SCLK will stop and SS and SSV will return to their default states. A transmit underrun error will occur at this point. PS025016-1013 PRELIMINARY Enhanced Serial Peripheral Interface Z8 Encore! XP® F1680 Series Product Specification 207 SCK (SSMD = 11, PHASE = 0, CLKPOL = 0) SS MOSI, MISO Bit7 Bit0 Bit7 frame n Bit0 Bit 7 frame n + 1 Figure 38. Synchronous Message Framing Mode (SSMD = 11), Multiple Frames 16.3.4. SPI Protocol Configuration This section describes in detail how to configure the ESPI block for the SPI protocol. In the SPI protocol the Master sources the SCK and asserts Slave Select signals to one or more Slaves. The Slave Select signals are typically active Low. 16.3.4.1. SPI Master Operation The ESPI block is configured for MASTER Mode operation by setting the MMEN bit = 1 in the ESPICTL register. The SSMD field of the ESPI Mode Register is set to 00 for SPI protocol mode. The PHASE, CLKPOL and WOR bits in the ESPICTL register and the NUMBITS field in the ESPI Mode Register must be set to be consistent with the Slave SPI devices. Typically for an SPI Master, SSIO = 1 and SSPO = 0. The appropriate GPIO pins are configured for the ESPI alternate function on the MOSI, MISO and SCK pins. Typically the GPIO for the ESPI SS pin is configured in an alternate function mode as well though the software can use any GPIO pin(s) to drive one or more Slave select lines. If the ESPI SS signal is not used to drive a Slave select the SSIO bit should still be set to 1 in a single Master system. Figures 39 and 40 display a block diagram of the the ESPI configured as an SPI Master. PS025016-1013 PRELIMINARY Enhanced Serial Peripheral Interface Z8 Encore! XP® F1680 Series Product Specification 208 ESPI Master To Slave’s SS Pin From Slave To Slave To Slave SS MISO 8-bit Shift Register Bit 0 Bit 7 MOSI Baud Rate Generator SCK Figure 39. ESPI Configured as an SPI Master in a Single Master, Single Slave System ESPI Master To Slave #2s SS Pin GPIO To Slave #1s SS Pin GPIO 8-bit Shift Register From Slaves MISO To Slaves To Slaves Bit 0 Bit 7 MOSI SCK Baud Rate Generator Figure 40. ESPI Configured as an SPI Master in a Single Master, Multiple Slave System 16.3.4.2. Multi-Master SPI Operation In a Multi-Master SPI system, all SCK pins are tied together, all MOSI pins are tied together and all MISO pins are tied together. All SPI pins must be configured in opendrain mode to prevent bus contention. At any time, only one SPI device is configured as the Master and all other devices on the bus are configured as slaves. The Master asserts the PS025016-1013 PRELIMINARY Enhanced Serial Peripheral Interface Z8 Encore! XP® F1680 Series Product Specification 209 SS pin on the selected slave. Then, the active Master drives the clock and transmits data on the SCK and MOSI pins to the SCK and MOSI pins on the Slave (including those Slaves which are not enabled). The enabled slave drives data out its MISO pin to the MISO Master pin. When the ESPI is configured as a Master in a Multi-Master SPI system, the SS pin must be configured as an input. The SS input signal on a device configured as a Master should remain High. If the SS signal on the active Master goes Low (indicating another Master is accessing this device as a Slave), a Collision error flag is set in the ESPI Status Register. The Slave select outputs on a Master in a Multi-Master system must come from GPIO pins. 16.3.4.3. SPI Slave Operation The ESPI block is configured for SLAVE Mode operation by setting the MMEN bit = 0 in the ESPICTL register and setting the SSIO bit = 0 in the ESPIMODE register. The SSMD field of the ESPI Mode Register is set to 00 for SPI protocol mode. The PHASE, CLKPOL and WOR bits in the ESPICTL register and the NUMBITS field in the ESPIMODE register must be set to be consistent with the other SPI devices. Typically for an SPI Slave, SSPO = 0. If the Slave has data to send to the Master, the data must be written to the Data Register before the transaction starts (first edge of SCK when SS is asserted). If the Data Register is not written prior to the Slave transaction, the MISO pin outputs all 1s. Due to the delay resulting from synchronization of the SS and SCK input signals to the internal system clock, the maximum SCK baud rate that can be supported in SLAVE Mode is the system clock frequency divided by 4. This rate is controlled by the SPI Master. Figure 41 displays the ESPI configuration in SPI SLAVE Mode. PS025016-1013 PRELIMINARY Enhanced Serial Peripheral Interface Z8 Encore! XP® F1680 Series Product Specification 210 SPI Slave From Master To Master From Master From Master SS 8-bit Shift Register MISO Bit 7 Bit 0 MOSI SCK Figure 41. ESPI Configured as an SPI Slave 16.3.5. Error Detection Error events detected by the ESPI block are described in this section. Error events generate an ESPI interrupt and set a bit in the ESPI Status Register. The error bits of the ESPI Status Register are Read/Write 1 to clear. 16.3.5.1. Transmit Underrun A transmit underrun error occurs for a Master with SSMD = 10 or 11 when a character transfer completes and TDRE = 1. In these modes when a transmit underrun occurs the transfer will be aborted (SCK will halt and SSV will be deasserted). For a Master in SPI mode (SSMD = 00), a transmit underrun is not signaled since SCK will pause and wait for the Data Register to be written. In SLAVE Mode, a transmit underrun error occurs if TDRE = 1 at the start of a transfer. When a transmit underrun occurs in SLAVE Mode, ESPI will transmit a character of all 1s. A transmit underrun sets the TUND bit in the ESPI Status Register to 1. Writing a 1 to TUND clears this error flag. 16.3.5.2. Mode Fault (Multi-Master Collision) A mode fault indicates when more than one Master is trying to communicate simultaneously (a Multi-Master collision) in SPI mode. The mode fault is detected when the enabled Master’s SS input pin is asserted. For this to happen the Control and Mode registers must PS025016-1013 PRELIMINARY Enhanced Serial Peripheral Interface Z8 Encore! XP® F1680 Series Product Specification 211 be configured with MMEN = 1, SSIO = 0 (SS is an input) and SS input = 0. A mode fault sets the COL bit in the ESPI Status Register to 1. Writing a 1 to COL clears this error flag. 16.3.5.3. Receive Overrun A receive overrun error occurs when a transfer completes and the RDRNE bit is still set from the previous transfer. A receive overrun sets the ROVR bit in the ESPI Status Register to 1. Writing a 1 to ROVR clears this error flag. The Receive Data Register is not overwritten and will contain the data from the transfer which initially set the RDRNE bit. Subsequent received data is lost until the RDRNE bit is cleared. In SPI MASTER Mode, a receive overrun will not occur. Instead, the SCK will be paused until software responds to the previous RDRNE/TDRE requests. 16.3.5.4. SLAVE Mode Abort In SLAVE Mode, if the SS pin deasserts before all bits in a character have been transferred, the transaction is aborted. When this condition occurs the ABT bit is set in the ESPI Status Register. A Slave abort error resets the Slave control logic to idle state. A Slave abort error is also asserted in SLAVE Mode, if BRGCTL = 1 and a baud rate generator time-out occurs. When BRGCTL = 1 in SLAVE Mode, the baud rate generator functions as a Watchdog Timer monitoring the SCK signal. The BRG counter is reloaded every time a transition on SCK occurs while SS is asserted. The Baud Rate Reload registers must be programmed with a value longer than the expected time between the SS assertion and the first SCK edge, between SCK transitions while SS is asserted and between the last SCK edge and SS deassertion. A time-out indicates the Master is stalled or disabled. Writing a 1 to ABT clears this error flag. 16.3.6. ESPI Interrupts ESPI has a single interrupt output which is asserted when any of the TDRE, TUND, COL, ABT, ROVR or RDRNE bits are set in the ESPI Status Register. The interrupt is a pulse which is generated when any one of the source bits initially sets. The TDRE and RDRNE interrupts can be enabled/disabled via the Data Interrupt Request Enable (DIRQE) bit of the ESPI Control Register. A transmit interrupt is asserted by the TDRE status bit when the ESPI block is enabled and the DIRQE bit is set. The TDRE bit in the Status register is cleared automatically when the Data Register is written or the ESPI block is disabled. After the Data Register is loaded into the Shift Register to start a new transfer, the TDRE bit will be set again, causing a new transmit interrupt. In SLAVE Mode, if information is being received but not transmitted the transmit interrupts can be eliminated by selecting Receive Only mode (ESPIEN1,0 = 01). A Master cannot operate in Receive Only mode since a write to the ESPI (Transmit) Data Register is still required to initiate the transfer of a character even if information is being received but not transmitted by the software application. PS025016-1013 PRELIMINARY Enhanced Serial Peripheral Interface Z8 Encore! XP® F1680 Series Product Specification 212 A receive interrupt is generated by the RDRNE status bit when the ESPI block is enabled, the DIRQE bit is set and a character transfer completes. At the end of the character transfer, the contents of the Shift Register are transferred into the Data Register, causing the RDRNE bit to assert. The RDRNE bit is cleared when the Data Buffer is read as empty. If information is being transmitted but not received by the software application, the receive interrupt can be eliminated by selecting Transmit Only mode (ESPIEN1,0 = 10) in either MASTER or SLAVE modes. When information is being sent and received under interrupt control, RDRNE and TDRE will both assert simultaneously at the end of a character transfer. Since the new receive data is in the Data Register, the receive interrupt must be serviced before the transmit interrupt. ESPI error interrupts occur if any of the TUND, COL, ABT and ROVR bits in the ESPI Status Register are set. These bits are cleared by writing a 1. If the ESPI is disabled (ESPIEN1, 0 = 00), an ESPI interrupt can be generated by a Baud Rate Generator timeout. This timer function must be enabled by setting the BRGCTL bit in the ESPICTL register. This timer interrupt does not set any of the bits of the ESPI Status Register. 16.3.7. ESPI Baud Rate Generator In ESPI MASTER Mode, the Baud Rate Generator creates a lower frequency serial clock (SCK) for data transmission synchronization between the Master and the external Slave. The input to the Baud Rate Generator is the system clock. The ESPI Baud Rate High and Low Byte registers combine to form a 16-bit reload value, BRG[15:0], for the ESPI Baud Rate Generator. The ESPI baud rate is calculated using the following equation: System Clock Frequency  Hz  SPI Baud Rate  bits § s  = -----------------------------------------------------------------------------------------2  BRG[15:0] Minimum baud rate is obtained by setting BRG[15:0] to 0000h for a clock divisor value of (2 x 65536 = 131072). When the ESPI is disabled, the Baud Rate Generator can function as a basic 16-bit timer with interrupt on time-out. Observe the following steps to configure the Baud Rate Generator as a timer with interrupt on time-out: 1. Disable the ESPI by clearing the ESPIEN1,0 bits in the ESPI Control Register. 2. Load the appropriate 16-bit count value into the ESPI Baud Rate High and Low Byte registers. 3. Enable the Baud Rate Generator timer function and associated interrupt by setting the BRGCTL bit in the ESPI Control Register to 1. When configured as a general purpose timer, the SPI BRG interrupt interval is calculated using the following equation: PS025016-1013 PRELIMINARY Enhanced Serial Peripheral Interface Z8 Encore! XP® F1680 Series Product Specification 213 SPI BRG Interrupt Interval (s) = System Clock Period (s)  BRG[15:0] 16.4. ESPI Control Register Definitions This section defines the features of the following ESPI Control registers. ESPI Data Register: see page 213 ESPI Transmit Data Command and Receive Data Buffer Control Register: see page 214 ESPI Control Register: see page 215 ESPI Mode Register: see page 217 ESPI Status Register: see page 219 ESPI State Register: see page 220 ESPI Baud Rate High and Low Byte Registers: see page 221 16.4.1. ESPI Data Register The ESPI Data Register, shown in Table 109, addresses both the outgoing Transmit Data Register and the incoming Receive Data Register. Reads from the ESPI Data Register return the contents of the Receive Data Register. The Receive Data Register is updated with the contents of the Shift Register at the end of each transfer. Writes to the ESPI Data Register load the Transmit Data Register unless TDRE = 0. Data is shifted out starting with bit 7. The last bit received resides in bit position 0. With the ESPI configured as a Master, writing a data byte to this register initiates the data transmission. With the ESPI configured as a Slave, writing a data byte to this register loads the Shift Register in preparation for the next data transfer with the external Master. In either the MASTER or SLAVE modes, if TDRE = 0, writes to this register are ignored. When the character length is less than 8 bits (as set by the NUMBITS field in the ESPI Mode Register), the transmit character must be left justified in the ESPI Data Register. A received character of less than 8 bits is right justified (last bit received is in bit position 0). For example, if the ESPI is configured for 4-bit characters, the transmit characters must be written to ESPIDATA[7:4] and the received characters are read from ESPIDATA[3:0]. PS025016-1013 PRELIMINARY Enhanced Serial Peripheral Interface Z8 Encore! XP® F1680 Series Product Specification 214 Table 109. ESPI Data Register (ESPIDATA) Bits 7 6 5 4 Field 2 1 0 DATA Reset R/W 3 X X X X X X X X R/W R/W R/W R/W R/W R/W R/W R/W Address F60h Bit Description [7:0] DATA Data Transmit and/or receive data. Writes to the ESPIDATA register load the Shift Register. Reads from the ESPIDATA register return the value of the Receive Data Register. 16.4.2. ESPI Transmit Data Command and Receive Data Buffer Control Register The ESPI Transmit Data Command and Receive Data Buffer Control Register, shown in Table 110, provides control of the SS pin when it is configured as an output (MASTER Mode), clear receive data buffer function and flag. The CRDR, TEOF and SSV bits can be controlled by a bus write to this register. Table 110. ESPI Transmit Data Command and Receive Data Buffer Control Register (ESPITDCR) Bits 7 Field CRDR RDFLAG Reset 0 00 0 0 R/W R R R R/W Address 6 5 4 3 2 1 0 TEOF SSV 0 0 0 R R/W R/W Reserved F61h Bit Description [7] CRDR Clear Receive Data Register Writing 1 to this bit is used to clear all data in receive data buffer. [6:5] Receive Data Buffer Flag RDFLAG This bit is used to indicate how many bytes stored in receive buffer. 00 = 0 or 4 bytes (see RDRNE in the ESPI Status Register). 01 = 1 byte. 02 = 2 bytes. 03 = 3 bytes. [4:2] Reserved These bits are reserved and must be programmed to 000. PS025016-1013 PRELIMINARY Enhanced Serial Peripheral Interface Z8 Encore! XP® F1680 Series Product Specification 215 Bit Description [1] TEOF Transmit End of Frame This bit is used in MASTER Mode to indicate that the data in the Transmit Data Register is the last byte of the transfer or frame. When the last byte has been sent SS (and SSV) will change state and TEOF will automatically clear. 0 = The data in the Transmit Data Register is not the last character in the message. 1 = The data in the Transmit Data Register is the last character in the message. [0] SSV Slave Select Value When SSIO = 1, writes to this register will control the value output on the SS pin. For more details, see the SSMD field of the ESPI Mode Register on page 217. 16.4.3. ESPI Control Register The ESPI Control Register, shown in Table 111, configures the ESPI for transmit and receive operations. Table 111. ESPI Control Register Bits 7 6 5 4 3 2 1 0 Field DIRQE ESPIEN1 BRGCTL PHASE CLKPOL WOR MMEN ESPIEN0 Reset 0 0 0 0 0 0 0 0 R/W R/W R/W R/W R/W R/W R/W R/W R/W Address F62h Bit Description [7] DIRQE Data Interrupt Request Enable This bit is used to disable or enable data (TDRE and RDRNE) interrupts. Disabling the data interrupts is needed to control data transfer by polling. Error interrupts are not disabled. To block all ESPI interrupt sources, clear the ESPI interrupt enable bit in the Interrupt Controller. 0 = TDRE and RDRNE assertions do not cause an interrupt. Use this setting if controlling data transfer by software polling of TDRE and RDRNE. The TUND, COL, ABT and ROVR bits will cause an interrupt. 1 = TDRE and RDRNE assertions will cause an interrupt. TUND, COL, ABT and ROVR will also cause interrupts. Use this setting when controlling data transfer via interrupt handlers. PS025016-1013 PRELIMINARY Enhanced Serial Peripheral Interface Z8 Encore! XP® F1680 Series Product Specification 216 Bit Description (Continued) [6,0] ESPI Enable and Direction Control ESPIEN1, 00 = The ESPI block is disabled. BRG can be used as a general-purpose timer by setting ESPIEN0 BRGCTL = 1. 01 = Receive Only Mode. Use this setting in SLAVE Mode if software application is receiving data but not sending. TDRE will not assert. Transmitted data will be all 1s. Not valid in MASTER Mode since Master must source data to drive the transfer. 10 = Transmit Only Mode Use this setting in MASTER or SLAVE Mode when the software application is sending data but not receiving. RDRNE will not assert. 11 = Transmit/Receive Mode Use this setting if the software application is both sending and receiving information. Both TDRE and RDRNE will be active. [5] Baud Rate Generator Control BRGCTL The function of this bit depends upon ESPIEN1,0. When ESPIEN1,0 = 00, this bit allows enabling the BRG to provide periodic interrupts. If the ESPI is disabled 0 = The Baud Rate Generator timer function is disabled. Reading the Baud Rate High and Low registers returns the BRG reload value. 1 = The Baud Rate Generator timer function and time-out interrupt is enabled. Reading the Baud Rate High and Low registers returns the BRG Counter value. If the ESPI is enabled 0 = Reading the Baud Rate High and Low registers returns the BRG reload value. If MMEN = 1, the BRG is enabled to generate SCK. If MMEN = 0, the BRG is disabled. 1 = Reading the Baud Rate High and Low registers returns the BRG Counter value. If MMEN = 1, the BRG is enabled to generate SCK. If MMEN = 0 the BRG is enabled to provide a Slave SCK time-out. See the SLAVE Mode Abort error description on page 211. Caution: If reading the counter one byte at a time while the BRG is counting keep in mind that the values will not be in sync. Zilog recommends reading the counter using (2-byte) word reads. [4] PHASE Phase Select Sets the phase relationship of the data to the clock. For more information about operation of the PHASE bit, see the ESPI Clock Phase and Polarity Control section on page 201. [3] Clock Polarity CLKPOL 0 = SCK idles Low (0). 1 = SCK idles High (1). [2] WOR Wire-OR (Open-Drain) Mode Enabled 0 = ESPI signal pins not configured for open-drain. 1 = All four ESPI signal pins (SCK, SS, MISO and MOSI) configured for open-drain function. This setting is typically used for multi-Master and/or Multi-Slave configurations. [1] MMEN ESPI MASTER Mode Enable This bit controls the data I/O pin selection and SCK direction. 0 = Data out on MISO, data in on MOSI (used in SPI SLAVE Mode), SCK is an input. 1 = Data out on MOSI, data in on MISO (used in SPI MASTER Mode), SCK is an output. PS025016-1013 PRELIMINARY Enhanced Serial Peripheral Interface Z8 Encore! XP® F1680 Series Product Specification 217 16.4.4. ESPI Mode Register The ESPI Mode Register, shown in Table 112, configures the character bit width and mode of the ESPI I/O pins. Table 112. ESPI Mode Register (ESPIMODE) Bits 7 6 5 4 3 2 0 SSIO SSPO Field SSMD Reset 000 0 0 0 0 0 R/W R/W R/W R/W R/W R/W R/W Address NUMBITS[2:0] 1 F63h Bit Description [7:5] SSMD Slave Select Mode This field selects the behavior of SS as a framing signal. For a detailed description of these modes, see Slave Select on page 200. 000 = SPI Mode When SSIO = 1, the SS pin is driven directly from the SSV bit in the Transmit Data Command Register. The Master software should set SSV (or a GPIO output if the SS pin is not connected to the appropriate Slave) to the asserted state prior to or on the same clock cycle that the Transmit Data Register is written with the initial byte. At the end of a frame (after the last RDRNE event), SSV will be automatically deasserted by hardware. In this mode, SCK is active only for data transfer (one clock cycle per bit transferred). 001 = Loopback Mode When ESPI is configured as Master (MMEN = 1), the outputs are deasserted and data is looped from Shift Register Out to Shift Register In. When ESPI is configured as a Slave (MMEN = 0) and SS in asserts, MISO (Slave output) is tied to MOSI (Slave input) to provide an asynchronous remote loop back (echo) function. 010 = I2S Mode (Synchronous Framing with SSV) In this mode, the value from SSV will be output by the Master on the SS pin with one SCK period before the data and will remain in that state until the start of the next frame. Typically this mode is used to send back to back frames with SS alternating on each frame. A frame boundary is indicated in the Master when SSV changes. A frame boundary is detected in the Slave by SS changing state. The SS framing signal will lead the frame by one SCK period. In this mode SCK will run continuously, starting with the initial SS assertion. Frames will run back-to-back as long as software continues to provide data. An example of this mode is the I2S protocol (Inter IC Sound) which is used to carry left and right channel audio data with the SS signal indicating which channel is being sent. In SLAVE Mode, the change in state of SS (Low to High or High to Low) triggers the start of a transaction on the next SCK cycle. PS025016-1013 PRELIMINARY Enhanced Serial Peripheral Interface Z8 Encore! XP® F1680 Series Product Specification 218 Bit Description (Continued) [4:2] Number of Data Bits Per Character to Transfer NUMBITS[2:0] This field contains the number of bits to shift for each character transfer. For information about valid bit positions when the character length is less than 8 bits, see the description of the ESPI Data Register on page 213. 000 = 8 bits 001 = 1 bit 010 = 2 bits 011 = 3 bits 100 = 4 bits 101 = 5 bits 110 = 6 bits 111 = 7 bits [1] SSIO Slave Select I/O This bit controls the direction of the SS pin. In single MASTER Mode, SSIO is set to 1 unless a separate GPIO pin is being used to provide the SS output function. In the SPI Slave or multi-Master configuration, SSIO is set to 0. 0 = SS pin configured as an input (SPI SLAVE and MULTI-MASTER modes). 1 = SS pin configured as an output (SPI SINGLE MASTER Mode). [0] SSPO Slave Select Polarity This bit controls the polarity of the SS pin. 0 = SS is active Low. (SSV = 1 corresponds to SS = 0). 1 = SS is active High. (SSV = 1 corresponds to SS = 1). PS025016-1013 PRELIMINARY Enhanced Serial Peripheral Interface Z8 Encore! XP® F1680 Series Product Specification 219 16.4.5. ESPI Status Register The ESPI Status Register, shown in Table 113, indicates the current state of the ESPI. All bits revert to their Reset state if the ESPI is disabled. Table 113. ESPI Status Register (ESPISTAT) Bits 7 6 5 4 3 2 1 0 Field TDRE TUND COL ABT ROVR RDRNE TFST SLAS Reset 1 0 0 0 0 0 0 1 R/W R R/W* R/W* R/W* R/W* R R R Address F64h Note: R/W* = Read access. Write a 1 to clear the bit to 0. Bit Description [7] TDRE Transmit Data Register Empty 0 = Transmit Data Register is full or ESPI is disabled. 1 = Transmit Data Register is empty. A write to the ESPI (Transmit) Data Register clears this bit. [6] TUND Transmit Underrun 0 = A Transmit Underrun error has not occurred. 1 = A Transmit Underrun error has occurred. [5] COL Collision 0 = A multi-Master collision (mode fault) has not occurred. 1 = A multi-Master collision (mode fault) has occurred. [4] ABT SLAVE Mode Transaction Abort This bit is set if the ESPI is configured in SLAVE Mode, a transaction is occurring and SS deasserts before all bits of a character have been transferred as defined by the NUMBITS field of the ESPIMODE register. This bit can also be set in SLAVE Mode by an SCK monitor timeout (MMEN = 0, BRGCTL = 1). 0 = A SLAVE Mode transaction abort has not occurred. 1 = A SLAVE Mode transaction abort has occurred. [3] ROVR Receive Overrun 0 = A Receive Overrun error has not occurred. 1 = A Receive Overrun error has occurred. [2] RDRNE Receive Data Register Not Empty 0 = Receive Data Register is empty. 1 = Receive Data Register is not empty. PS025016-1013 PRELIMINARY Enhanced Serial Peripheral Interface Z8 Encore! XP® F1680 Series Product Specification 220 Bit Description (Continued) [1] TFST Transfer Status 0 = No data transfer is currently in progress. 1 = Data transfer is currently in progress. [0] SLAS Slave Select Reading this bit returns the current value of the SS pin. 0 = The SS pin input is Low. 1 = The SS pin input is High. 16.4.6. ESPI State Register The ESPI State Register, shown in Table 114, lets you observe the ESPI clock, data and internal state. Table 114. ESPI State Register (ESPISTATE) Bits 7 6 Field SCKI SDI ESPISTATE Reset 0 0 0 R/W R R R Address 5 4 3 2 1 0 F65h Bit Description [7] SCKI Serial Clock Input This bit reflects the state of the serial clock pin. 0 = The SCK input pin is Low. 1 = The SCK input pin is High. [6] SDI Serial Data Input This bit reflects the state of the serial data input (MOSI or MISO depending on the MMEN bit). 0 = The serial data input pin is Low. 1 = The serial data input pin is High. [5:0] ESPISTATE ESPI State Machine Indicates the current state of the internal ESPI State Machine. This information is intended for manufacturing test purposes. The state values may change in future hardware revisions and are not intended to be used by a software driver. PS025016-1013 PRELIMINARY Enhanced Serial Peripheral Interface Z8 Encore! XP® F1680 Series Product Specification 221 Table 115 defines the valid ESPI states. Table 115. ESPISTATE Values ESPISTATE Value Description 00_0000 Idle 00_0001 Slave Wait For SCK 01_0001 Master Ready 10_1110 Bit 7 Receive 10_1111 Bit 7 Transmit 10_1100 Bit 6 Receive 10_1101 Bit 6 Transmit 10_1010 Bit 5 Receive 10_1011 Bit 5 Transmit 10_1000 Bit 4 Receive 10_1001 Bit 4 Transmit 10_0110 Bit 3 Receive 10_0111 Bit 3 Transmit 10_0100 Bit 2 Receive 10_0101 Bit 2 Transmit 10_0010 Bit 1 Receive 10_0011 Bit 1 Transmit 10_0000 Bit 0 Receive 10_0001 Bit 0 Transmit 16.4.7. ESPI Baud Rate High and Low Byte Registers The ESPI Baud Rate High and Low Byte registers, shown in Tables 116 and 117, combine to form a 16-bit reload value, BRG[15:0], for the ESPI Baud Rate Generator. The ESPI baud rate is calculated using the following equation: System Clock Frequency  Hz  SPI Baud Rate  bits § s  = -------------------------------------------------------------------------------2  BRG[15:0] The minimum baud rate is obtained by setting BRG[15:0] to 0000h for a clock divisor value of (2 x 65536 = 131072). PS025016-1013 PRELIMINARY Enhanced Serial Peripheral Interface Z8 Encore! XP® F1680 Series Product Specification 222 Table 116. ESPI Baud Rate High Byte Register (ESPIBRH) Bits 7 6 5 4 Field 2 1 0 BRH Reset R/W 3 1 1 1 1 1 1 1 1 R/W R/W R/W R/W R/W R/W R/W R/W Address F66h Bit Description [7:0] BRH ESPI Baud Rate High Byte The most significant byte, BRG[15:8], of the ESPI Baud Rate Generator’s reload value. Table 117. ESPI Baud Rate Low Byte Register (ESPIBRL) Bits 7 6 5 4 Field 2 1 0 BRL Reset R/W 3 1 1 1 1 1 1 1 1 R/W R/W R/W R/W R/W R/W R/W R/w Address F67h Bit Description [7:0] BRL ESPI Baud Rate Low Byte The least significant byte, BRG[7:0], of the ESPI Baud Rate Generator’s reload value. PS025016-1013 PRELIMINARY Enhanced Serial Peripheral Interface Z8 Encore! XP® F1680 Series Product Specification 223 Chapter 17. I2C Master/Slave Controller The I2C Master/Slave Controller ensures that the Z8 Encore! XP F1680 Series devices are bus-compatible with the I2C protocol. The I2C bus consists of the serial data signal (SDA) and a serial clock signal (SCL) bidirectional lines. The features of I2C controller include: • • • • • • • • • Operates in MASTER/SLAVE or SLAVE ONLY modes Supports arbitration in a multimaster environment (MASTER/SLAVE Mode) Supports data rates up to 400 Kbps 7-bit or 10-bit slave address recognition (interrupt only on address match) Optional general call address recognition Optional digital filter on receive SDA, SCL lines Optional interactive receive mode allows software interpretation of each received address and/or data byte before acknowledging Unrestricted number of data bytes per transfer Baud Rate Generator can be used as a general-purpose timer with an interrupt, if the I2C controller is disabled 17.1. Architecture Figure 42 displays the architecture of the I2C controller. PS025016-1013 PRELIMINARY I2C Master/Slave Controller Z8 Encore! XP® F1680 Series Product Specification 224 SDA SCL Shift SHIFT Load I2CDATA Baud Rate Generator I2CBRH I2CBRL Tx/Rx State Machine I2CISTAT I2CCTL I2CMODE I2CSLVAD I2C Interrupt I2CSTATE Register Bus Figure 42. I2C Controller Block Diagram 17.1.1. I2C Master/Slave Controller Registers Table 118 summarizes the I2C Master/Slave controller’s software-accessible registers. Table 118. I2C Master/Slave Controller Registers Name Abbreviation Description I C Data I2CDATA Transmit/Receive Data Register. I2C I2CISTAT Interrupt status register. I2CCTL Control Register—basic control functions. 2 Interrupt Status 2 I C Control PS025016-1013 PRELIMINARY I2C Master/Slave Controller Z8 Encore! XP® F1680 Series Product Specification 225 Table 118. I2C Master/Slave Controller Registers (Continued) Name Abbreviation Description I C Baud Rate High I2CBRH High byte of baud rate generator initialization value. I2C 2 I2CBRL Low byte of baud rate generator initialization value. 2 Baud Rate Low I2CSTATE State register. 2 I C Mode I2CMODE Selects MASTER or SLAVE modes, 7-bit or 10-bit addressing; configure address recognition, define slave address bits [9:8]. I2C Slave Address I2CSLVAD Defines slave address bits [7:0]. I C State 17.2. Operation The I2C Master/Slave Controller operates in MASTER/SLAVE Mode, SLAVE ONLY Mode, or with master arbitration. In MASTER/SLAVE Mode, it can be used as the only Master on the bus or as one of the several masters on the bus, with arbitration. In a MultiMaster environment, the controller switches from MASTER to SLAVE Mode on losing arbitration. Though slave operation is fully supported in MASTER/SLAVE Mode, if a device is intended to operate only as a slave, then SLAVE ONLY mode can be selected. In SLAVE ONLY mode, the device will not initiate a transaction, even if the software inadvertently sets the start bit. 17.2.1. SDA and SCL Signals The I2C circuit sends all addresses, Data and Acknowledge signals over the SDA line, with most-significant bit first. SCL is the clock for the I2C bus. When the SDA and SCL pin alternate functions are selected for their respective GPIO ports, the pins are automatically configured for open-drain operation. The Master is responsible for driving the SCL clock signal. During the Low period of the clock, a slave can hold the SCL signal Low to suspend the transaction if it is not ready to proceed. The Master releases the clock at the end of the Low period and notices that the clock remains Low instead of returning to a High level. When the slave releases the clock, the I2C master continues the transaction. All data is transferred in bytes; there is no limit to the amount of data transferred in one operation. When transmitting address, data, or an Acknowledge, the SDA signal changes in the middle of the Low period of SCL. When receiving address, Data, or an Acknowledge; the SDA signal is sampled in the middle of the High period of SCL. A low-pass digital filter can be applied to the SDA and SCL receive signals by setting the Filter Enable (FILTEN) bit in the I2C Control Register. When the filter is enabled, any glitch that is less than a system clock period in width will be rejected. This filter should be PS025016-1013 PRELIMINARY I2C Master/Slave Controller Z8 Encore! XP® F1680 Series Product Specification 226 enabled when running in I2C FAST Mode (400 Kbps) and can also be used at lower data rates. 17.2.2. I2C Interrupts The I2C controller contains multiple interrupt sources that are combined into one interrupt request signal to the interrupt controller. If the I2C controller is enabled, the source of the interrupt is determined by which bits are set in the I2CISTAT Register. If the I2C controller is disabled, the BRG controller is used to generate general-purpose timer interrupts. Each interrupt source, other than the baud rate generator interrupt, features an associated bit in the I2CISTAT Register that clears automatically when software reads the register or performs another task, such as reading/writing the Data Register. 17.2.2.1. Transmit Interrupts Transmit interrupts (TDRE bit = 1 in I2CISTAT) occur under the following conditions, both of which must be true: • • The Transmit Data Register is empty and the TXI bit = 1 in the I2C Control Register. The I2C controller is enabled with one of the following elements: – The first bit of a 10-bit address is shifted out. – The first bit of the final byte of an address is shifted out and the RD bit is deasserted. – The first bit of a data byte is shifted out. Writing to the I2C Data Register always clears the TRDE bit to 0. 17.2.2.2. Receive Interrupts Receive interrupts (RDRF bit = 1 in I2CISTAT) occur when a byte of data has been received by the I2C controller. The RDRF bit is cleared by reading from the I2C Data Register. If the RDRF interrupt is not serviced prior to the completion of the next Receive byte, the I2C controller holds SCL Low during the final data bit of the next byte until RDRF is cleared, to prevent receive overruns. A receive interrupt does not occur when a Slave receives an address byte or for data bytes following a slave address that do not match. An exception is if the Interactive Receive Mode (IRM ) bit is set in the I2CMODE Register, in which case Receive interrupts occur for all Receive address and data bytes in SLAVE Mode. 17.2.2.3. Slave Address Match Interrupts Slave address match interrupts (SAM bit = 1 in I2CISTAT) occur when the I2C controller is in SLAVE Mode and an address received matches the unique slave address. The General Call Address (0000_0000) and STARTBYTE (0000_0001) are recognized if the PS025016-1013 PRELIMINARY I2C Master/Slave Controller Z8 Encore! XP® F1680 Series Product Specification 227 GCE bit = 1 in the I2CMODE Register. The software checks the RD bit in the I2CISTAT Register to determine if the transaction is a Read or Write transaction. The General Call Address and STARTBYTE address are also distinguished by the RD bit. The General Call Address (GCA) bit of the I2CISTAT Register indicates whether the address match occurred on the unique slave address or the General Call/STARTBYTE address. The SAM bit clears automatically when the I2CISTAT Register is read. If configured via the MODE[1:0] field of the I2C Mode Register for 7-bit slave addressing, the most significant 7 bits of the first byte of the transaction are compared against the SLA[6:0] bits of the Slave Address Register. If configured for 10-bit slave addressing, the first byte of the transaction is compared against {11110,SLA[9:8], R/W} and the second byte is compared against SLA[7:0]. 17.2.2.4. Arbitration Lost Interrupts Arbitration Lost interrupts (ARBLST bit = 1 in I2CISTAT) occur when the I2C controller is in MASTER Mode and loses arbitration (outputs 1 on SDA and receives 0 on SDA). The I2C controller switches to SLAVE Mode when this instance occurs. This bit clears automatically when the I2CISTAT Register is read. 17.2.2.5. Stop/Restart Interrupts A Stop/Restart event interrupt (SPRS bit = 1 in I2CISTAT) occurs when the I2C controller is operating in SLAVE Mode and a stop or restart condition is received, indicating the end of the transaction. The RSTR bit in the I2C State Register indicates whether the bit is set due to a stop or restart condition. When a restart occurs, a new transaction by the same master is expected to follow. This bit is cleared automatically when the I2CISTAT Register is read. The Stop/Restart interrupt occurs only on a selected (address match) slave. 17.2.2.6. Not Acknowledge Interrupts Not Acknowledge interrupts (NCKI bit = 1 in I2CISTAT) occur in MASTER Mode when Not Acknowledge is received or sent by the I2C controller and the start or stop bit is not set in the I2C Control Register. In MASTER Mode, the Not Acknowledge interrupt clears by setting the start or stop bit. When this interrupt occurs in MASTER Mode, the I2C controller waits until it is cleared before performing any action. In SLAVE Mode, the Not Acknowledge interrupt occurs when a Not Acknowledge is received in response to data sent. The NCKI bit clears in SLAVE Mode when software reads the I2CISTAT Register. 17.2.2.7. General Purpose Timer Interrupt from Baud Rate Generator If the I2C controller is disabled (IEN bit in the I2CCTL Register = 0) and the BIRQ bit in the I2CCTL Register = 1, an interrupt is generated when the baud rate generator (BRG) counts down to 1. The baud rate generator reloads and continues counting, providing a periodic interrupt. None of the bits in the I2CISTAT Register are set, allowing the BRG in the I2C Controller to be used as a general-purpose timer when the I2C Controller is disabled. PS025016-1013 PRELIMINARY I2C Master/Slave Controller Z8 Encore! XP® F1680 Series Product Specification 228 17.2.3. Start and Stop Conditions The Master generates the start and stop conditions to start or end a transaction. To start a transaction, the I2C controller generates a start condition by pulling the SDA signal Low while SCL is High. To complete a transaction, the I2C controller generates a stop condition by creating a Low-to-High transition of the SDA signal while the SCL signal is High. These start and stop events occur when the start and stop bits in the I2C Control Register are written by software to begin or end a transaction. Any byte transfer currently under way including the Acknowledge phase finishes before the start or stop condition occurs. 17.2.4. Software Control of I2C Transactions The I2C controller is configured via the I2C Control and I2C Mode registers. The MODE[1:0] field of the I2C Mode Register allows the configuration of the I2C controller for MASTER/SLAVE or SLAVE ONLY mode and configures the slave for 7-bit or 10-bit addressing recognition. MASTER/SLAVE Mode can be used for: • • • MASTER ONLY operation in a Single Master/One or More Slave I2C system MASTER/SLAVE in a Multimaster/multislave I2C system SLAVE ONLY operation in an I2C system In SLAVE ONLY mode, the start bit of the I2C Control Register is ignored (software cannot initiate a master transaction by accident) and operation to SLAVE ONLY Mode is restricted thereby preventing accidental operation in MASTER Mode. The software controls I2C transactions by enabling the I2C controller interrupt in the interrupt controller or by polling the I2C Status Register. To use interrupts, the I2C interrupt must be enabled in the interrupt controller and followed by executing an EI instruction. The TXI bit in the I2C Control Register must be set to enable transmit interrupts. An I2C interrupt service routine then checks the I2C Status Register to determine the cause of the interrupt. To control transactions by polling, the TDRE, RDRF, SAM, ARBLST, SPRS and NCKI interrupt bits in the I2C Status Register should be polled. The TDRE bit asserts regardless of the state of the TXI bit. 17.2.5. Master Transactions The following sections describe Master Read and Write transactions to both 7-bit and 10bit slaves. PS025016-1013 PRELIMINARY I2C Master/Slave Controller Z8 Encore! XP® F1680 Series Product Specification 229 17.2.5.1. Master Arbitration If a Master loses arbitration during the address byte it releases the SDA line, switches to SLAVE Mode and monitors the address to determine if it is selected as a Slave. If a Master loses arbitration during the transmission of a data byte, it releases the SDA line and waits for the next stop or start condition. The Master detects a loss of arbitration when a 1 is transmitted but a 0 is received from the bus in the same bit-time. This loss occurs if more than one Master is simultaneously accessing the bus. Loss of arbitration occurs during the address phase (two or more Masters accessing different slaves) or during the data phase, when the masters are attempting to Write different data to the same Slave. When a Master loses arbitration, the software is informed by means of the Arbitration Lost interrupt. The software can repeat the same transaction at a later time. A special case can occur when a Slave transaction starts just before the software attempts to start a new master transaction by setting the start bit. In this case, the state machine enters its Slave states before the start bit is set and as a result the I2C controller will not arbitrate. If a Slave address match occurs and the I2C controller receives/transmits data, the start bit is cleared and an Arbitration Lost interrupt is asserted. The software can minimize the chance of this instance occurring by checking the busy bit in the I2CSTATE Register before initiating a Master transaction. If a slave address match does not occur, the Arbitration Lost interrupt will not occur and the start bit will not be cleared. The I2C controller will initiate the master transaction after the I2C bus is no longer busy. 17.2.5.2. Master Address-Only Transactions It is sometimes preferable to perform an address-only transaction to determine if a particular slave device is able to respond. This transaction can be performed by monitoring the ACKV bit in the I2CSTATE Register after the address has been written to the I2CDATA Register and the start bit has been set. After the ACKV bit is set, the ACK bit in the I2CSTATE Register determines if the slave is able to communicate. The stop bit must be set in the I2CCTL Register to terminate the transaction without transferring data. For a 10-bit slave address, if the first address byte is acknowledged, the second address byte should also be sent to determine if the preferred Slave is responding. Another approach is to set both the stop and start bits (for sending a 7-bit address). After both bits have been cleared (7-bit address has been sent and transaction is complete), the ACK bit can be read to determine if the Slave has acknowledged. For a 10-bit Slave, set the stop bit after the second TDRE interrupt (which indicates that the second address byte is being sent). 17.2.5.3. Master Transaction Diagrams In the following transaction diagrams, the shaded regions indicate the data that is transferred from the Master to the Slave and the unshaded regions indicate the data that is PS025016-1013 PRELIMINARY I2C Master/Slave Controller Z8 Encore! XP® F1680 Series Product Specification 230 transferred from the Slave to the Master. The transaction field labels are defined as follows: S Start W Write A Acknowledge A Not Acknowledge P Stop 17.2.5.4. Master Write Transaction with a 7-Bit Address Figure 43 displays the data transfer format from a Master to a 7-bit addressed slave. S Slave Address W=0 A Data A Data A Data A/A P/S Figure 43. Data Transfer Format—Master Write Transaction with a 7-Bit Address Observe the following steps for a Master transmit operation to a 7-bit addressed slave: 1. The software initializes the MODE field in the I2C Mode Register for MASTER/ SLAVE Mode with either a 7-bit or 10-bit slave address. The MODE field selects the address width for this mode when addressed as a slave (but not for the remote slave). The software asserts the IEN bit in the I2C Control Register. 2. The software asserts the TXI bit of the I2C Control Register to enable transmit interrupts. 3. The I2C interrupt asserts, because the I2C Data Register is empty. 4. The software responds to the TDRE bit by writing a 7-bit slave address plus the Write bit (which is cleared to 0) to the I2C Data Register. 5. The software sets the start bit of the I2C Control Register. 6. The I2C controller sends a start condition to the I2C slave. 7. The I2C controller loads the I2C Shift Register with the contents of the I2C Data Register. 8. After one bit of the address has been shifted out by the SDA signal, the transmit interrupt asserts. 9. The software responds by writing the transmit data into the I2C Data Register. 10. The I2C controller shifts the remainder of the address and the Write bit out via the SDA signal. PS025016-1013 PRELIMINARY I2C Master/Slave Controller Z8 Encore! XP® F1680 Series Product Specification 231 11. The I2C slave sends an Acknowledge (by pulling the SDA signal Low) during the next High period of SCL. The I2C controller sets the ACK bit in the I2C Status Register. If the slave does not acknowledge the address byte, the I2C controller sets the NCKI bit in the I2C Status Register, sets the ACKV bit and clears the ACK bit in the I2C State Register. The software responds to the Not Acknowledge interrupt by setting the stop bit and clearing the TXI bit. The I2C controller flushes the Transmit Data Register, sends a stop condition on the bus and clears the stop and NCKI bits. The transaction is complete and the following steps can be ignored. 12. The I2C controller loads the contents of the I2C Shift Register with the contents of the I2C Data Register. 13. The I2C controller shifts the data out via the SDA signal. After the first bit is sent, the transmit interrupt asserts. 14. If more bytes remain to be sent, return to Step 9. 15. When there is no more data to be sent, the software responds by setting the stop bit of the I2C Control Register (or the start bit to initiate a new transaction). 16. If no additional transaction is queued by the master, the software can clear the TXI bit of the I2C Control Register. 17. The I2C controller completes transmission of the data on the SDA signal. 18. The I2C controller sends a stop condition to the I2C bus. Note: If the slave terminates the transaction early by responding with a Not Acknowledge during the transfer, the I2C controller asserts the NCKI interrupt and halts. The software must terminate the transaction by setting either the stop bit (end transaction) or the start bit (end this transaction, start a new one). In this case, it is not necessary for software to set the FLUSH bit of the I2CCTL Register to flush the data that was previously written but not transmitted. The I2C controller hardware automatically flushes transmit data in the not acknowledge case. 17.2.5.5. Master Write Transaction with a 10-Bit Address Figure 44 displays the data transfer format from a Master to a 10-bit addressed slave. S Slave Address 1st Byte W=0 A Slave Address 2nd Byte A Data A Data A/A F/S Figure 44. Data Transfer Format—Master Write Transaction with a 10-Bit Address PS025016-1013 PRELIMINARY I2C Master/Slave Controller Z8 Encore! XP® F1680 Series Product Specification 232 The first 7 bits transmitted in the first byte are 11110XX. The 2 XX bits are the two most significant bits of the 10-bit address. The lowest bit of the first byte transferred is the Read/Write control bit (which is cleared to 0). The transmit operation is performed in the same manner as 7-bit addressing. Observe the following steps for a master transmit operation to a 10-bit addressed slave: 1. The software initializes the MODE field in the I2C Mode Register for MASTER/ SLAVE Mode with 7- or 10-bit addressing (the I2C bus protocol allows the mixing of slave address types). The MODE field selects the address width for this mode when addressed as a slave (but not for the remote slave). The software asserts the IEN bit in the I2C Control Register. 2. The software asserts the TXI bit of the I2C Control Register to enable transmit interrupts. 3. The I2C interrupt asserts because the I2C Data Register is empty. 4. The software responds to the TDRE interrupt by writing the first Slave Address byte (11110xx0). The least-significant bit must be 0 for the write operation. 5. The software asserts the start bit of the I2C Control Register. 6. The I2C controller sends a start condition to the I2C Slave. 7. The I2C controller loads the I2C Shift Register with the contents of the I2C Data Register. 8. After one bit of the address is shifted out by the SDA signal, the transmit interrupt asserts. 9. The software responds by writing the second byte of address into the contents of the I2C Data Register. 10. The I2C controller shifts the remainder of the first byte of the address and the Write bit out via the SDA signal. 11. The I2C slave sends an Acknowledge by pulling the SDA signal Low during the next High period of SCL. The I2C controller sets the ACK bit in the I2C Status Register. If the slave does not acknowledge the first address byte, the I2C controller sets the NCKI bit in the I2C Status Register, sets the ACKV bit and clears the ACK bit in the I2C State Register. The software responds to the Not Acknowledge interrupt by setting the stop bit and clearing the TXI bit. The I2C controller flushes the second address byte from the Data Register, sends a stop condition on the bus and clears the stop and NCKI bits. The transaction is complete and the following steps can be ignored. 12. The I2C controller loads the I2C Shift Register with the contents of the I2C Data Register (2nd address byte). 13. The I2C controller shifts the second address byte out via the SDA signal. After the first bit has been sent, the transmit interrupt asserts. PS025016-1013 PRELIMINARY I2C Master/Slave Controller Z8 Encore! XP® F1680 Series Product Specification 233 14. The software responds by writing the data to be written out to the I2C Control Register. 15. The I2C controller shifts out the remainder of the second byte of the slave address (or ensuring data bytes, if looping) via the SDA signal. 16. The I2C slave sends an Acknowledge by pulling the SDA signal Low during the next High period of SCL. The I2C controller sets the ACK bit in the I2C Status Register. If the slave does not acknowledge, see the second paragraph of Step 11. 17. The I2C controller shifts the data out by the SDA signal. After the first bit is sent, the transmit interrupt asserts. 18. If more bytes remain to be sent, return to Step 14. 19. The software responds by asserting the stop bit of the I2C Control Register. 20. The I2C controller completes transmission of the data on the SDA signal. 21. The I2C controller sends a stop condition to the I2C bus. Note: If the slave responds with a Not Acknowledge during the transfer, the I2C controller asserts the NCKI bit, sets the ACKV bit, clears the ACK bit in the I2C State Register and halts. The software terminates the transaction by setting either the stop bit (end transaction) or the start bit (end this transaction, start a new one). The Transmit Data Register is flushed automatically. 17.2.5.6. Master Read Transaction with a 7-Bit Address Figure 45 displays the data transfer format for a Read operation to a 7-bit addressed slave. S Slave Address R=1 A Data A Data A P/S Figure 45. Data Transfer Format—Master Read Transaction with a 7-Bit Address Observe the following steps for a Master Read operation to a 7-bit addressed slave: 1. The software initializes the MODE field in the I2C Mode Register for MASTER/ SLAVE Mode with 7- or 10-bit addressing (the I2C bus protocol allows the mixing of slave address types). The MODE field selects the address width for this mode when addressed as a slave (but not for the remote slave). The software asserts the IEN bit in the I2C Control Register. 2. The software writes the I2C Data Register with a 7-bit slave address, plus the Read bit (which is set to 1). 3. The software asserts the start bit of the I2C Control Register. PS025016-1013 PRELIMINARY I2C Master/Slave Controller Z8 Encore! XP® F1680 Series Product Specification 234 4. If this operation is a single-byte transfer, the software asserts the NAK bit of the I2C Control Register so that after the first byte of data has been read by the I2C controller, a Not Acknowledge instruction is sent to the I2C slave. 5. The I2C controller sends a start condition. 6. The I2C controller sends the address and Read bit out via the SDA signal. 7. The I2C slave acknowledges the address by pulling the SDA signal Low during the next High period of SCL. If the slave does not acknowledge the address byte, the I2C controller sets the NCKI bit in the I2C Status Register, sets the ACKV bit and clears the ACK bit in the I2C State Register. The software responds to the Not Acknowledge interrupt by setting the stop bit and clearing the TXI bit. The I2C controller flushes the Transmit Data Register, sends a stop condition on the bus and clears the stop and NCKI bits. The transaction is complete and the following steps can be ignored. 8. The I2C controller shifts in the first byte of data from the I2C slave on the SDA signal. 9. The I2C controller asserts the receive interrupt. 10. The software responds by reading the I2C Data Register. If the next data byte is to be the final byte, the software must set the NAK bit of the I2C Control Register. 11. The I2C controller sends a Not Acknowledge to the I2C slave if the next byte is the final byte; otherwise, it sends an Acknowledge. 12. If there are more bytes to transfer, the I2C controller returns to Step 7. 13. A NAK interrupt (NCKI bit in I2CISTAT) is generated by the I2C controller. 14. The software responds by setting the stop bit of the I2C Control Register. 15. A stop condition is sent to the I2C slave. 17.2.5.7. Master Read Transaction with a 10-Bit Address Figure 46 displays the read transaction format for a 10-bit addressed Slave. S Slave Address Slave Address Slave Address W=0 A R=1 A S 1st Byte 2nd Byte 1st Byte A Data A Data A P Figure 46. Data Transfer Format—Master Read Transaction with a 10-Bit Address The first 7 bits transmitted in the first byte are 11110XX. The two XX bits are the two most-significant bits of the 10-bit address. The lowest bit of the first byte transferred is the write control bit. Observe the following data transfer procedure for a Read operation to a 10-bit addressed slave: PS025016-1013 PRELIMINARY I2C Master/Slave Controller Z8 Encore! XP® F1680 Series Product Specification 235 1. The software initializes the MODE field in the I2C Mode Register for MASTER/ SLAVE Mode with 7- or 10-bit addressing (the I2C bus protocol allows the mixing of slave address types). The MODE field selects the address width for this mode when addressed as a slave (but not for the remote slave). The software asserts the IEN bit in the I2C Control Register. 2. The software writes 11110b, followed by the two most-significant address bits and a 0 (write) to the I2C Data Register. 3. The software asserts the start bit of the I2C Control Register. 4. The I2C controller sends a start condition. 5. The I2C controller loads the I2C Shift Register with the contents of the I2C Data Register. 6. After the first bit has been shifted out, a transmit interrupt is asserted. 7. The software responds by writing the least significant eight bits of address to the I2C Data Register. 8. The I2C controller completes shifting of the first address byte. 9. The I2C slave sends an Acknowledge by pulling the SDA signal Low during the next High period of SCL. If the slave does not acknowledge the address byte, the I2C controller sets the NCKI bit in the I2C Status Register, sets the ACKV bit and clears the ACK bit in the I2C State Register. The software responds to the Not Acknowledge interrupt by setting the stop bit and clearing the TXI bit. The I2C controller flushes the Transmit Data Register, sends the stop condition on the bus and clears the stop and NCKI bits. The transaction is complete and the following steps can be ignored. 10. The I2C controller loads the I2C Shift Register with the contents of the I2C Data Register (the lower byte of the 10-bit address). 11. The I2C controller shifts out the next eight bits of the address. After the first bit shifts, the I2C controller generates a transmit interrupt. 12. The software responds by setting the start bit of the I2C Control Register to generate a repeated start condition. 13. The software writes 11110b, followed by the 2-bit slave address and a 1 (Read) to the I2C Data Register. 14. If the user chooses to read only one byte, the software responds by setting the NAK bit of the I2C Control Register. 15. After the I2C controller shifts out the address bits listed in Step 9 (the second address transfer), the I2C slave sends an Acknowledge by pulling the SDA signal Low during the next High period of SCL. If the slave does not acknowledge the address byte, the I2C controller sets the NCKI bit in the I2C Status Register, sets the ACKV bit and clears the ACK bit in the I2C PS025016-1013 PRELIMINARY I2C Master/Slave Controller Z8 Encore! XP® F1680 Series Product Specification 236 State Register. The software responds to the Not Acknowledge interrupt by setting the stop bit and clearing the TXI bit. The I2C controller flushes the Transmit Data Register, sends the stop condition on the bus and clears the stop and NCKI bits. The transaction is complete and the following steps can be ignored. 16. The I2C controller sends a repeated start condition. 17. The I2C controller loads the I2C Shift Register with the contents of the I2C Data Register (the third address transfer). 18. The I2C controller sends 11110b, followed by the two most-significant bits of the slave read address and a 1 (Read). 19. The I2C slave sends an Acknowledge by pulling the SDA signal Low during the next High period of SCL. 20. The I2C controller shifts in a byte of data from the slave. 21. The I2C controller asserts the Receive interrupt. 22. The software responds by reading the I2C Data Register. If the next data byte is to be the final byte, the software must set the NAK bit of the I2C Control Register. 23. The I2C controller sends an Acknowledge or Not Acknowledge to the I2C Slave, based on the value of the NAK bit. 24. If there are more bytes to transfer, the I2C controller returns to Step 18. 25. The I2C controller generates a NAK interrupt (the NCKI bit in the I2CISTAT Register). 26. The software responds by setting the stop bit of the I2C Control Register. 27. A stop condition is sent to the I2C Slave. 17.2.6. Slave Transactions The following sections describe Read and Write transactions to the I2C controller configured for 7-bit and 10-bit Slave modes. 17.2.6.1. Slave Address Recognition The following two slave address recognition options are supported; a description of each follows. • • Slave 7-Bit Address Recognition Mode Slave 10-Bit Address Recognition Mode Slave 7-Bit Address Recognition Mode. If IRM = 0 during the address phase and the controller is configured for MASTER/SLAVE or SLAVE 7-bit address mode, the PS025016-1013 PRELIMINARY I2C Master/Slave Controller Z8 Encore! XP® F1680 Series Product Specification 237 hardware detects a match to the 7-bit slave address defined in the I2CSLVAD Register and generates the slave address match interrupt (the SAM bit = 1 in the I2CISTAT Register). The I2C controller automatically responds during the Acknowledge phase with the value in the NAK bit of the I2CCTL Register. Slave 10-Bit Address Recognition Mode. If IRM = 0 during the address phase and the controller is configured for MASTER/SLAVE or SLAVE 10-bit address mode, the hardware detects a match to the 10-bit slave address defined in the I2CMODE and I2CSLVAD registers and generates the slave address match interrupt (the SAM bit = 1 in the I2CISTAT Register). The I2C controller automatically responds during the Acknowledge phase with the value in the NAK bit of the I2CCTL Register. 17.2.6.2. General Call and Start Byte Address Recognition If GCE = 1 and IRM = 0 during the address phase and the controller is configured for MASTER/SLAVE or SLAVE in either 7- or 10-bit address modes, the hardware detects a match to the General Call Address or the start byte and generates the slave address match interrupt. A General Call Address is a 7-bit address of all 0’s with the R/W bit = 0. A start byte is a 7-bit address of all 0’s with the R/W bit = 1. The SAM and GCA bits are set in the I2CISTAT Register. The RD bit in the I2CISTAT Register distinguishes a General Call Address from a start byte which is cleared to 0 for a General Call Address). For a General Call Address, the I2C controller automatically responds during the address acknowledge phase with the value in the NAK bit of the I2CCTL Register. If the software is set to process the data bytes associated with the GCA bit, the IRM bit can optionally be set following the SAM interrupt to allow the software to examine each received data byte before deciding to set or clear the NAK bit. A start byte will not be acknowledged—a requirement of the I2C specification. 17.2.6.3. Software Address Recognition To disable hardware address recognition, the IRM bit must be set to 1 prior to the reception of the address byte(s). When IRM = 1, each received byte generates a receive interrupt (RDRF = 1 in the I2CISTAT Register). The software must examine each byte and determine whether to set or clear the NAK bit. The slave holds SCL Low during the Acknowledge phase until the software responds by writing to the I2CCTL Register. The value written to the NAK bit is used by the controller to drive the I2C bus, then releasing the SCL. The SAM and GCA bits are not set when IRM = 1 during the address phase, but the RD bit is updated based on the first address byte. 17.2.6.4. Slave Transaction Diagrams In the following transaction diagrams, the shaded regions indicate data transferred from the Master to the Slave and the unshaded regions indicate the data transferred from the Slave to the Master. The transaction field labels are defined as follows: PS025016-1013 PRELIMINARY I2C Master/Slave Controller Z8 Encore! XP® F1680 Series Product Specification 238 S Start W Write A Acknowledge A Not Acknowledge P Stop 17.2.6.5. Slave Receive Transaction with 7-Bit Address The data transfer format for writing data from a Master to a Slave in 7-bit address mode is displayed in Figure 47. The procedure that follows describes the I2C Master/Slave Controller operating as a slave in 7-bit addressing mode and receiving data from the bus master. S Slave Address W=0 A Data A Data A Data A/A P/S Figure 47. Data Transfer Format—Slave Receive Transaction with 7-Bit Address 1. The software configures the controller for operation as a slave in 7-bit addressing mode, as follows: a. Initialize the MODE field in the I2C Mode Register for either SLAVE ONLY mode or MASTER/SLAVE Mode with 7-bit addressing. b. Optionally set the GCE bit. c. Initialize the SLA[6:0] bits in the I2C Slave Address Register. d. Set IEN = 1 in the I2C Control Register. Set NAK = 0 in the I2C Control Register. 2. The bus master initiates a transfer, sending the address byte. In SLAVE Mode, the I2C controller recognizes its own address and detects that R/W bit = 0 (written from the master to the slave). The I2C controller acknowledges indicating it is available to accept the transaction. The SAM bit in the I2CISTAT Register is set to 1, causing an interrupt. The RD bit in the I2CISTAT Register is cleared to 0, indicating a Write to the slave. The I2C controller holds the SCL signal Low waiting for the software to load the first data byte. 3. The software responds to the interrupt by reading the I2CISTAT Register (which clears the SAM bit). After seeing the SAM bit to 1, the software checks the RD bit. Because RD = 0, no immediate action is required until the first byte of data is received. If software is only able to accept a single byte, it sets the NAK bit in the I2CCTL Register at this time. 4. The Master detects the Acknowledge and sends the byte of data. PS025016-1013 PRELIMINARY I2C Master/Slave Controller Z8 Encore! XP® F1680 Series Product Specification 239 5. The I2C controller receives the data byte and responds with Acknowledge or Not Acknowledge depending on the state of the NAK bit in the I2CCTL Register. The I2C controller generates the receive data interrupt by setting the RDRF bit in the I2CISTAT Register. 6. The software responds by reading the I2CISTAT Register, finding the RDRF bit = 1 and reading the I2CDATA Register clearing the RDRF bit. If software can accept only one more data byte it sets the NAK bit in the I2CCTL Register. 7. The master and slave loops through Step 4 to Step 6 until the master detects a Not Acknowledge instruction or runs out of data to send. 8. The master sends the stop or restart signal on the bus. Either of these signals can cause the I2C controller to assert a stop interrupt (the stop bit = 1 in the I2CISTAT Register). Because the slave received data from the master, the software takes no action in response to the stop interrupt other than reading the I2CISTAT Register to clear the stop bit in the I2CISTAT Register. 17.2.6.6. Slave Receive Transaction with 10-Bit Address The data transfer format for writing data from a master to a slave with 10-bit addressing is displayed in Figure 48. The procedure that follows describes the I2C Master/Slave Controller operating as a slave in 10-bit addressing mode and receiving data from the bus master. s S Slave Address 1st Byte W=0 A Slave Address 2nd Byte A Data A Data A/A P/S Figure 48. Data Transfer Format—Slave Receive Transaction with 10-Bit Address 1. The software configures the controller for operation as a slave in 10-bit addressing mode, as follows: a. Initialize the MODE field in the I2CMODE Register for either SLAVE ONLY mode or MASTER/SLAVE Mode with 10-bit addressing. b. Optionally set the GCE bit. c. Initialize the SLA[7:0] bits in the I2CSLVAD Register and the SLA[9:8] bits in the I2CMODE Register. d. Set IEN = 1 in the I2CCTL Register. Set NAK = 0 in the I2C Control Register. 2. The Master initiates a transfer, sending the first address byte. The I2C controller recognizes the start of a 10-bit address with a match to SLA[9:8] and detects R/W bit = 0 (a Write from the master to the slave). The I2C controller acknowledges, indicating it is available to accept the transaction. 3. The Master sends the second address byte. The SLAVE Mode I2C controller detects an address match between the second address byte and SLA[7:0]. The SAM bit in the PS025016-1013 PRELIMINARY I2C Master/Slave Controller Z8 Encore! XP® F1680 Series Product Specification 240 I2CISTAT Register is set to 1, thereby causing an interrupt. The RD bit is cleared to 0, indicating a Write to the slave. The I2C controller acknowledges, indicating it is available to accept the data. 4. The software responds to the interrupt by reading the I2CISTAT Register, which clears the SAM bit. Because RD = 0, no immediate action is taken by the software until the first byte of data is received. If the software is only able to accept a single byte, it sets the NAK bit in the I2CCTL Register. 5. The Master detects the Acknowledge and sends the first byte of data. 6. The I2C controller receives the first byte and responds with Acknowledge or Not Acknowledge, depending on the state of the NAK bit in the I2CCTL Register. The I2C controller generates the receive data interrupt by setting the RDRF bit in the I2CISTAT Register. 7. The software responds by reading the I2CISTAT Register, finding the RDRF bit = 1 and then reading the I2CDATA Register, which clears the RDRF bit. If the software can accept only one more data byte, it sets the NAK bit in the I2CCTL Register. 8. The Master and Slave loops through Step 5 to Step 7 until the Master detects a Not Acknowledge instruction or runs out of data to send. 9. The Master sends the stop or restart signal on the bus. Either of these signals can cause the I2C controller to assert the stop interrupt (the stop bit = 1 in the I2CISTAT Register). Because the slave received data from the master, the software takes no action in response to the STOP interrupt other than reading the I2CISTAT Register to clear the stop bit. 17.2.6.7. Slave Transmit Transaction With 7-bit Address The data transfer format for a master reading data from a slave in 7-bit address mode is displayed in Figure 49. The procedure that follows describes the I2C Master/Slave Controller operating as a slave in 7-bit addressing mode and transmitting data to the bus master. S Slave Address R=1 A Data A Data A P/S Figure 49. Data Transfer Format—Slave Transmit Transaction with 7-bit Address 1. The software configures the controller for operation as a slave in 7-bit addressing mode, as follows: a. Initialize the MODE field in the I2C Mode Register for either SLAVE ONLY mode or MASTER/SLAVE Mode with 7-bit addressing. b. Optionally set the GCE bit. c. Initialize the SLA[6:0] bits in the I2C Slave Address Register. PS025016-1013 PRELIMINARY I2C Master/Slave Controller Z8 Encore! XP® F1680 Series Product Specification 241 d. Set IEN = 1 in the I2C Control Register. Set NAK = 0 in the I2C Control Register. 2. The Master initiates a transfer by sending the address byte. The SLAVE Mode I2C controller finds an address match and detects that the R/W bit = 1 (read by the master from the slave). The I2C controller acknowledges, indicating that it is ready to accept the transaction. The SAM bit in the I2CISTAT Register is set to 1, causing an interrupt. The RD bit is set to 1, indicating a Read from the slave. 3. The software responds to the interrupt by reading the I2CISTAT Register, thereby clearing the SAM bit. Because RD = 1, the software responds by loading the first data byte into the I2CDATA Register. The software sets the TXI bit in the I2CCTL Register to enable transmit interrupts. When the master initiates the data transfer, the I2C controller holds SCL Low until the software has written the first data byte to the I2CDATA Register. 4. SCL is released and the first data byte is shifted out. 5. After the first bit of the first data byte has been transferred, the I2C controller sets the TDRE bit, which asserts the transmit data interrupt. 6. The software responds to the transmit data interrupt (TDRE = 1) by loading the next data byte into the I2CDATA Register, which clears TDRE. 7. After the data byte has been received by the master, the master transmits an Acknowledge instruction (or Not Acknowledge instruction if this byte is the final data byte). 8. The bus cycles through Step 5 to Step 7 until the final byte has been transferred. If the software has not yet loaded the next data byte when the master brings SCL Low to transfer the most significant data bit, the slave I2C controller holds SCL Low until the Data Register has been written. When a Not Acknowledge instruction is received by the slave, the I2C controller sets the NCKI bit in the I2CISTAT Register causing the Not Acknowledge interrupt to be generated. 9. The software responds to the Not Acknowledge interrupt by clearing the TXI bit in the I2CCTL Register and by asserting the FLUSH bit of the I2CCTL Register to empty the Data Register. 10. When the Master has completed the final acknowledge cycle, it asserts a stop or restart condition on the bus. 11. The Slave I2C controller asserts the stop/restart interrupt (set SPRS bit in I2CISTAT Register). 12. The software responds to the stop/restart interrupt by reading the I2CISTAT Register, which clears the SPRS bit. 17.2.6.8. Slave Transmit Transaction With 10-Bit Address The data transfer format for a master reading data from a slave with 10-bit addressing is displayed in Figure 50. The following procedure describes the I2C Master/Slave Controller operating as a slave in 10-bit addressing mode, transmitting data to the bus master. PS025016-1013 PRELIMINARY I2C Master/Slave Controller Z8 Encore! XP® F1680 Series Product Specification 242 S Slave Address Slave Address A W=0 A 1st Byte 2nd Byte S Slave Address R=1 A 1st Byte Data A Data A P Figure 50. Data Transfer Format—Slave Transmit Transaction with 10-Bit Address 1. The software configures the controller for operation as a slave in 10-bit addressing mode. a. Initialize the MODE field in the I2C Mode Register for either SLAVE ONLY mode or MASTER/SLAVE Mode with 10-bit addressing. b. Optionally set the GCE bit. c. Initialize the SLA[7:0] bits in the I2CSLVAD Register and SLA[9:8] in the I2C MODE Register. d. Set IEN = 1 and NAK = 0 in the I2C Control Register. 2. The Master initiates a transfer by sending the first address byte. The SLAVE Mode I2C controller recognizes the start of a 10-bit address with a match to SLA[9:8] and detects R/W bit = 0 (a Write from the master to the slave). The I2C controller acknowledges indicating it is available to accept the transaction. 3. The Master sends the second address byte. The SLAVE Mode I2C controller compares the second address byte with the value in SLA[7:0]. If there is a match, the SAM bit in the I2CISTAT Register is set = 1, causing a slave address match interrupt. The RD bit is set = 0, indicating a write to the slave. If a match occurs, the I2C controller acknowledges on the I2C bus, indicating it is available to accept the data. 4. The software responds to the slave address match interrupt by reading the I2CISTAT Register, which clears the SAM bit. Because the RD bit = 0, no further action is required. 5. The Master sees the Acknowledge and sends a restart instruction, followed by the first address byte with R/W set to 1. The SLAVE Mode I2C controller recognizes the restart instruction followed by the first address byte with a match to SLA[9:8] and detects R/W = 1 (the master reads from the slave). The slave I2C controller sets the SAM bit in the I2CISTAT Register which causes the slave address match interrupt. The RD bit is set = 1. The SLAVE Mode I2C controller acknowledges on the bus. 6. The software responds to the interrupt by reading the I2CISTAT Register clearing the SAM bit. The software loads the initial data byte into the I2CDATA Register and sets the TXI bit in the I2CCTL Register. 7. The Master starts the data transfer by asserting SCL Low. After the I2C controller has data available to transmit, the SCL is released and the master proceeds to shift the first data byte. PS025016-1013 PRELIMINARY I2C Master/Slave Controller Z8 Encore! XP® F1680 Series Product Specification 243 8. After the first bit of the first data byte has been transferred, the I2C controller sets the TDRE bit which asserts the transmit data interrupt. 9. The software responds to the transmit data interrupt by loading the next data byte into the I2CDATA Register. 10. The I2C Master shifts in the remainder of the data byte. The Master transmits the Acknowledge (or Not Acknowledge, if this byte is the final data byte). 11. The bus cycles through Step 7 to Step 10 until the final byte is transferred. If the software has not yet loaded the next data byte when the master brings SCL Low to transfer the most significant data bit, the slave I2C controller holds SCL Low until the Data Register is written. When a Not Acknowledge is received by the slave, the I2C controller sets the NCKI bit in the I2CISTAT Register, causing the NAK interrupt to be generated. 12. The software responds to the NAK interrupt by clearing the TXI bit in the I2CCTL Register and by asserting the FLUSH bit of the I2CCTL Register. 13. When the Master has completed the Acknowledge cycle of the last transfer, it asserts a stop or restart condition on the bus. 14. The Slave I2C controller asserts the stop/restart interrupt (sets the SPRS bit in the I2CISTAT Register). 15. The software responds to the stop interrupt by reading the I2CISTAT Register and clearing the SPRS bit. 17.3. I2C Control Register Definitions This section defines the features of the following I2C Control registers. I2C Data Register: see page 243 I2C Interrupt Status Register: see page 245 I2C Interrupt Status Register: see page 245 I2C Baud Rate High and Low Byte Registers: see page 248 I2C State Register: see page 250 I2C Mode Register: see page 253 I2C Slave Address Register: see page 255 17.3.1. I2C Data Register The I2C Data Register listed in Table 119 contains the data that is to be loaded into the Shift Register to transmit onto the I2C bus. This register also contains data that is loaded PS025016-1013 PRELIMINARY I2C Master/Slave Controller Z8 Encore! XP® F1680 Series Product Specification 244 from the Shift Register after it is received from the I2C bus. The I2C Shift Register is not accessible in the Register File address space, but is used only to buffer incoming and outgoing data. Writes by the software to the I2CDATA Register are blocked if a slave Write transaction is underway (the I2C controller is in SLAVE Mode and data is being received). Table 119. I2C Data Register (I2CDATA = F50h) Bits 7 6 5 4 3 2 1 0 Field Data 7 Data 6 Data 5 Data 4 Data 3 Data 2 Data 1 Data 0 Reset 0 0 0 0 0 0 0 0 R/W R/W R/W R/W R/W R/W R/W R/W R/W Address F50h Bit Position Value Description [7:0] DATA — PS025016-1013 I2C Data Byte PRELIMINARY I2C Master/Slave Controller Z8 Encore! XP® F1680 Series Product Specification 245 17.3.2. I2C Interrupt Status Register The read-only I2C Interrupt Status Register, shown in Table 120, indicates the cause of any current I2C interrupt and provides status of the I2C controller. When an interrupt occurs, one or more of the TDRE, RDRF, SAM, ARBLST, SPRS or NCKI bits is set. The GCA and RD bits do not generate an interrupt but rather provide status associated with the SAM bit interrupt. Table 120. I2C Interrupt Status Register (I2CISTAT = F51h) Bits 7 6 5 4 3 2 1 0 Field TDRE RDRF SAM GCA RD ARBLST SPRS NCKI Reset 1 0 0 0 0 0 0 0 R/W R R R R R R R R Address F51h Bit Description [7] TDRE Transmit Data Register Empty When the I2C controller is enabled, this bit is 1 when the I2C Data Register is empty. When set, this bit causes the I2C controller to generate an interrupt, except when the I2C controller is shifting in data during the reception of a byte or when shifting an address and the RD bit is set. This bit clears by writing to the I2CDATA Register. [6] RDRF Receive Data Register Full This bit is set = 1 when the I2C controller is enabled and the I2C controller has received a byte of data. When asserted, this bit causes the I2C controller to generate an interrupt. This bit clears by reading the I2CDATA Register. [5] SAM Slave Address Match This bit is set = 1 if the I2C controller is enabled in SLAVE Mode and an address is received that matches the unique slave address or General Call Address (if enabled by the GCE bit in the I2C Mode Register). In 10-bit addressing mode, this bit is not set until a match is achieved on both address bytes. When this bit is set, the RD and GCA bits are also valid. This bit clears by reading the I2CISTAT Register. [4] GCA General Call Address This bit is set in SLAVE Mode when the General Call Address or Start byte is recognized (in either 7 or 10 bit SLAVE Mode). The GCE bit in the I2C Mode Register must be set to enable recognition of the General Call Address and Start byte. This bit clears when IEN = 0 and is updated following the first address byte of each SLAVE Mode transaction. A General Call Address is distinguished from a Start byte by the value of the RD bit (RD = 0 for General Call Address, 1 for Start byte). [3] RD Read This bit indicates the direction of transfer of the data. It is set when the Master is reading data from the Slave. This bit matches the least-significant bit of the address byte after the start condition occurs (for both MASTER and SLAVE modes). This bit clears when IEN = 0 and is updated following the first address byte of each transaction. PS025016-1013 PRELIMINARY I2C Master/Slave Controller Z8 Encore! XP® F1680 Series Product Specification 246 Bit Description (Continued) [2] Arbitration Lost ARBLST This bit is set when the I2C controller is enabled in MASTER Mode and loses arbitration (outputs a 1 on SDA and receives a 0 on SDA). The ARBLST bit clears when the I2CISTAT Register is read. [1] SPRS Stop/Restart Condition Interrupt This bit is set when the I2C controller is enabled in SLAVE Mode and detects a stop or restart condition during a transaction directed to this slave. This bit clears when the I2CISTAT Register is read. Read the RSTR bit of the I2CSTATE Register to determine whether the interrupt was caused by a stop or restart condition. [0] NCKI NAK Interrupt In MASTER Mode, this bit is set when a Not Acknowledge condition is received or sent and neither the start nor the stop bit is active. In MASTER Mode, this bit can only be cleared by setting the start or stop bits. In SLAVE Mode, this bit is set when a Not Acknowledge condition is received (Master reading data from Slave), indicating the master is finished reading. A stop or restart condition follows. In SLAVE Mode this bit clears when the I2CISTAT Register is read. PS025016-1013 PRELIMINARY I2C Master/Slave Controller Z8 Encore! XP® F1680 Series Product Specification 247 17.3.3. I2C Control Register The I2C Control Register, shown in Table 121, enables and configures I2C operation. The R/W1 bit can be set (written to 1) when IEN = 1, but cannot be cleared (written to 0). Note: Table 121. I2C Control Register (I2CCTL) Bits 7 6 5 4 3 2 1 0 Field IEN START STOP BIRQ TXI NAK FLUSH FILTEN Reset 0 0 0 0 0 0 0 0 R/W R/W1 R/W1 R/W R/W R/W1 W R/W R/W Address F52h Bit Description [7] IEN I2C Enable This bit enables the I2C controller. [6] START Send Start Condition When set, this bit causes the I2C controller (when configured as the master) to send a start condition. After it is asserted, this bit is cleared by the I2C controller after it sends the start condition or by deasserting the IEN bit. If this bit is 1, it cannot be cleared by writing to the bit. After this bit is set, a start condition is sent if there is data in the I2CDATA or I2C Shift Register. If there is no data in one of these registers, the I2C controller waits until data is loaded. If this bit is set while the I2C controller is shifting out data, it generates a restart condition after the byte shifts and the Acknowledge phase completes. If the stop bit is also set, it waits until the stop condition is sent before the start condition. If start is set while a SLAVE Mode transaction is underway to this device, the start bit will be cleared and ARBLST bit in the Interrupt Status Register will be set. [5] STOP Send Stop Condition When set, this bit causes the I2C controller (when configured as the master) to send the stop condition after the byte in the I2C Shift Register has completed transmission or after a byte is received in a receive operation. When set, this bit is reset by the I2C controller after a stop condition has been sent or by deasserting the IEN bit. If this bit is 1, it cannot be cleared to 0 by writing to the register. If stop is set while a SLAVE Mode transaction is underway, the stop bit is cleared by hardware. [4] BIRQ Baud Rate Generator Interrupt Request This bit is ignored when the I2C controller is enabled. If this bit is set = 1 when the I2C controller is disabled (IEN = 0), the baud rate generator is used as an additional timer causing an interrupt to occur every time the baud rate generator counts down to one. The baud rate generator runs continuously in this mode, generating periodic interrupts. PS025016-1013 PRELIMINARY I2C Master/Slave Controller Z8 Encore! XP® F1680 Series Product Specification 248 Bit Description (Continued) [3] TXI Enable TDRE Interrupts This bit enables interrupts when the I2C Data Register is empty. [2] NAK Send NAK Setting this bit sends a Not Acknowledge condition after the next byte of data has been received. It is automatically deasserted after the Not Acknowledge is sent or the IEN bit is cleared. If this bit is 1, it cannot be cleared to 0 by writing to the register. [1] FLUSH Flush Data Setting this bit clears the I2C Data Register and sets the TDRE bit to 1. This bit allows flushing of the I2C Data Register when an NAK condition is received after the next data byte is written to the I2C Data Register. Reading this bit always returns 0. [0] FILTEN I2C Signal Filter Enable Setting this bit enables low-pass digital filters on the SDA and SCL input signals. This function provides the spike suppression filter required in I2C Fast Mode. These filters reject any input pulse with periods less than a full system clock cycle. The filters introduce a 3-system clock cycle latency on the inputs. 17.3.4. I2C Baud Rate High and Low Byte Registers The I2C Baud Rate High and Low Byte registers, shown in Tables 122 and 123, combine to form a 16-bit reload value, BRG[15:0], for the I2C Baud Rate Generator. The I2C baud rate is calculated using the following equation. I2C Baud Rate (bits/s) = System Clock Frequency (Hz) 4 x BRG[15:0] Note: If BRG = 0000h, use 10000h in the equation. Table 122. I2C Baud Rate High Byte Register (I2CBRH = 53h) Bits 7 6 5 4 Field 2 1 0 BRH Reset R/W 3 1 1 1 1 1 1 1 1 R/W R/W R/W R/W R/W R/W R/W R/W Address F53h Bit Position Value [7:0] BRH I2C Baud Rate High Byte The most significant byte, BRG[15:8], of the I2C Baud Rate Generator’s reload value. PS025016-1013 Description PRELIMINARY I2C Master/Slave Controller Z8 Encore! XP® F1680 Series Product Specification 249 Note: If the DIAG bit in the I2C Mode Register is set to 1, a read of the I2CBRH Register returns the current value of the I2C Baud Rate Counter[15:8]. Table 123. I2C Baud Rate Low Byte Register (I2CBRL = F54h) Bits 7 6 5 4 Field 3 2 1 0 BRL Reset R/W 1 1 1 1 1 1 1 1 R/W R/W R/W R/W R/W R/W R/W R/W Address Bit Position F54h Value Description 2 [7:0] BRL I C Baud Rate Low Byte The least significant byte, BRG[7:0], of the I2C Baud Rate Generator’s reload value. Note: If the DIAG bit in the I2C Mode Register is set to 1, a read of the I2CBRL Register returns the current value of the I2C Baud Rate Counter[7:0]. PS025016-1013 PRELIMINARY I2C Master/Slave Controller Z8 Encore! XP® F1680 Series Product Specification 250 17.3.5. I2C State Register The read-only I2C State Register, shown in Table 124, provides information about the state of the I2C bus and the I2C bus controller. When the DIAG bit of the I2C Mode Register is cleared, this register provides information about the internal state of the I2C controller and I2C bus; see Table 126. When the DIAG bit of the I2C Mode Register is set, this register returns the value of the I2C controller state machine. Table 124. I2C State Register (I2CSTATE)—Description when DIAG = 1 Bits 7 Field 6 5 4 3 I2CSTATE_H 2 1 0 I2CSTATE_L Reset 0 0 0 0 0 0 0 0 R/W R R R R R R R R Address F55h Bit Description [7:4] I2CSTATE_H I2C State This field defines the current state of the I2C controller. It is the most significant nibble of the internal state machine. Table 126 defines the states for this field. [3:0] I2CSTATE_L Least Significant Nibble of the I2C State Machine This field defines the substates for the states defined by I2CSTATE_H. Table 127 defines the values for this field. PS025016-1013 PRELIMINARY I2C Master/Slave Controller Z8 Encore! XP® F1680 Series Product Specification 251 Table 125. I2C State Register (I2CSTATE)—Description when DIAG = 0 Bits 7 6 5 4 3 2 1 0 Field ACKV ACK AS DS 10B RSTR SCLOUT BUSY Reset 0 0 0 0 0 0 1 0 R/W R R R R R R R R Address F55h Bit Description [7] ACKV ACK Valid This bit is set, if sending data (Master or Slave) and the ACK bit in this register is valid for the byte just transmitted. This bit can be monitored if it is appropriate for software to verify the ACK value before writing the next byte to be sent. To operate in this mode, the Data Register must not be written when TDRE asserts; instead, the software waits for ACKV to assert. This bit clears when transmission of the next byte begins or the transaction is ended by a stop or restart condition. [6] ACK Acknowledge This bit indicates the status of the Acknowledge for the last byte transmitted or received. This bit is set for an Acknowledge and cleared for a Not Acknowledge condition. [5] AS Address State This bit is active High while the address is being transferred on the I2C bus. [4] DS Data State This bit is active High while the data is being transferred on the I2C bus. [3] 10B 10B This bit indicates whether a 7-bit or 10-bit address is being transmitted when operating as a Master. After the start bit is set, if the five most-significant bits of the address are 11110B, this bit is set. When set, it is Reset after the address has been sent. [2] RSTR RESTART This bit is updated each time a stop or restart interrupt occurs (SPRS bit set in I2CISTAT Register). 0 = Stop condition. 1 = Restart condition. [1] Serial Clock Output SCLOUT Current value of Serial Clock being output onto the bus. The actual values of the SCL and SDA signals on the I2C bus can be observed via the GPIO Input Register. [0] BUSY I2C Bus Busy 0 = No activity on the I2C Bus. 1 = A transaction is underway on the I2C bus. PS025016-1013 PRELIMINARY I2C Master/Slave Controller Z8 Encore! XP® F1680 Series Product Specification 252 Table 126. I2CSTATE_H State Encoding State Name State Description 0000 Idle I2C bus is idle or I2C controller is disabled. 0001 Slave Start I2C controller has received a start condition. 0010 Slave Bystander Address did not match; ignore remainder of transaction. 0011 Slave Wait Waiting for stop or restart condition after sending a Not Acknowledge instruction. 0100 Master Stop2 Master completing stop condition (SCL = 1, SDA = 1). 0101 Master Start/Restart MASTER Mode sending start condition (SCL = 1, SDA = 0). 0110 Master Stop1 Master initiating stop condition (SCL = 1, SDA = 0). 0111 Master Wait Master received a Not Acknowledge instruction, waiting for software to assert stop or start control bits. 1000 Slave Transmit Data Nine substates, one for each data bit and one for the Acknowledge. 1001 Slave Receive Data Nine substates, one for each data bit and one for the Acknowledge. 1010 Slave Receive Addr1 Slave receiving first address byte (7- and 10-bit addressing) Nine substates, one for each address bit and one for the Acknowledge. 1011 Slave Receive Addr2 Slave Receiving second address byte (10-bit addressing) nine substates, one for each address bit and one for the Acknowledge. 1100 Master Transmit Data Nine substates, one for each data bit and one for the Acknowledge. 1101 Master Receive Data Nine substates, one for each data bit and one for the Acknowledge. 1110 Master Transmit Addr1 Master sending first address byte (7- and 10-bit addressing) nine substates, one for each address bit and one for the Acknowledge. 1111 Master Transmit Addr2 Master sending second address byte (10-bit addressing) nine substates, one for each address bit and one for the Acknowledge. Table 127. I2CSTATE_L State I2CSTATE_H Substate I2CSTATE_L Substate Name State Description 0000–0100 0000 — There are no substates for these I2CSTATE_H values. 0110–0111 0000 — There are no substates for these I2CSTATE_H values. 0101 0000 Master Start Initiating a new transaction 0001 Master Restart Master is ending one transaction and starting a new one without letting the bus go idle. PS025016-1013 PRELIMINARY I2C Master/Slave Controller Z8 Encore! XP® F1680 Series Product Specification 253 Table 127. I2CSTATE_L (Continued) State I2CSTATE_H Substate I2CSTATE_L Substate Name State Description 1000–1111 0111 Send/Receive bit 7 Sending/Receiving most significant bit. 0110 Send/Receive bit 6 0101 Send/Receive bit 5 0100 Send/Receive bit 4 0011 Send/Receive bit 3 0010 Send/Receive bit 2 0001 Send/Receive bit 1 0000 Send/Receive bit 0 Sending/Receiving least significant bit. 1000 Send/Receive Acknowledge Sending/Receiving Acknowledge. 17.3.6. I2C Mode Register The I2C Mode Register, shown in Table 128, provides control over master versus slave operating mode, slave address and diagnostic modes. Table 128. I2C Mode Register (I2C Mode = F56h) Bits 7 Field Reserved Reset R/W 6 5 4 3 MODE[1:0] IRM GCE SLA[9:8] DIAG 0 0 0 0 0 0 R R/W R/W R/W R/W R/W Address 2 1 0 F56h Bit Description [7] Reserved; must be 0. [6:5] MODE[1:0] Selects the I2C Controller Operational Mode 00 = MASTER/SLAVE capable (supports multi-master arbitration) with 7-bit Slave address. 01 = MASTER/SLAVE capable (supports multi-master arbitration) with 10-bit slave address. 10 = Slave Only capable with 7-bit address. 11 = Slave Only capable with 10-bit address. PS025016-1013 PRELIMINARY I2C Master/Slave Controller Z8 Encore! XP® F1680 Series Product Specification 254 Bit Description (Continued) [4] IRM Interactive Receive Mode Valid in SLAVE Mode when software needs to interpret each received byte before acknowledging. This bit is useful for processing the data bytes following a General Call Address or if software wants to disable hardware address recognition. 0 = Acknowledge occurs automatically and is determined by the value of the NAK bit of the I2CCTL Register. 1 = A receive interrupt is generated for each byte received (address or data). The SCL is held Low during the Acknowledge cycle until software writes to the I2CCTL Register. The value written to the NAK bit of the I2CCTL Register is output on SDA. This value allows software to Acknowledge or Not Acknowledge after interpreting the associated address/data byte. [3] GCE General Call Address Enable Enables reception of messages beginning with the General Call Address or start byte. 0 = Do not accept a message with the General Call Address or start byte. 1 = Do accept a message with the General Call Address or start byte. When an address match occurs, the GCA and RD bits in the I2C Status Register indicates whether the address matched the General Call Address/start byte or not. Following the General Call Address byte, the software can set the IRM bit that allows software to examine the following data byte(s) before acknowledging. [2:1] SLA[9:8] Slave Address Bits 9 and 8 Initialize with the appropriate slave address value when using 10-bit slave addressing. These bits are ignored when using 7-bit slave addressing. [0] DIAG Diagnostic Mode Selects read back value of the Baud Rate Reload and State registers. 0 = Reading the Baud Rate registers returns the Baud Rate register values. Reading the State register returns I2C controller state information. 1 = Reading the Baud Rate registers returns the current value of the baud rate counter. Reading the State register returns additional state information. PS025016-1013 PRELIMINARY I2C Master/Slave Controller Z8 Encore! XP® F1680 Series Product Specification 255 17.3.7. I2C Slave Address Register The I2C Slave Address Register, shown in Table 129, provides control over the lower order address bits used in 7 and 10 bit slave address recognition. Table 129. I2C Slave Address Register (I2CSLVAD = 57h) Bits 7 6 5 4 3 Field SLA[7:0] Reset 00h R/W R/W Address F57h Bit 2 1 0 Description [7:0] Slave Address Bits SLA[7:0] Initialize with the appropriate Slave address value. When using 7-bit Slave addressing, SLA[9:7] are ignored. PS025016-1013 PRELIMINARY I2C Master/Slave Controller Z8 Encore! XP® F1680 Series Product Specification 256 Chapter 18. Comparator The Z8 Encore! XP F1680 Series devices feature two same general purpose comparators that compares two analog input signals. For each comparator, a GPIO (C0INP/C1INP) pin provides the positive comparator input, the negative input (C0INN/C1INN) can be taken from either an external GPIO pin or an internal reference. The output of each comparator is available as an interrupt source or can be routed to an external pin using the GPIO multiplex. Features for each comparator include: • • • • • • Two inputs which are connected using the GPIO multiplex (MUX) One input can be connected to a programmable internal reference One input can be connected to the on-chip temperature sensor Output can trigger timer counting Output can be either an interrupt source or an output to an external pin Operation in STOP Mode 18.1. Operation One of the comparator inputs can be connected to an internal reference which is a userselectable reference that is user-programmable with 200 mV resolution. The comparator can be powered down to save supply current or to continue to operate in STOP Mode. For details, see the Power Control Register 0 section on page 44. In STOP Mode, the comparator interrupt (if enabled) automatically initiates a Stop Mode Recovery and generates an interrupt request. In the Reset Status Register (see page 40), the stop bit is set to 1. Also, the Comparator request bit in the Interrupt Request 1 Register (see page 74) is set. Following completion of the Stop Mode Recovery, and if interrupts are enabled, the CPU responds to the interrupt request by fetching the comparator interrupt vector. Caution: Because of the propagation delay of the comparator, spurious interrupts can result after enabling the comparator. Zilog recommends not enabling the comparator without first disabling interrupts, then waiting for the comparator output to settle. The following code example shows how to safely enable the comparator: di ldx CMP0,r0 nop PS025016-1013 PRELIMINARY Comparator Z8 Encore! XP® F1680 Series Product Specification 257 nop ; wait for output to settle ldx IRQ0,#0 ; clear any spurious interrupts pending ei 18.2. Comparator Control Register Definitions This section defines the features of the following Comparator Control registers. Comparator 0 Control Register: see page 257 Comparator 1 Control Register: see page 258 18.2.1. Comparator 0 Control Register The Comparator 0 Control Register (CMP0), shown in Table 130, configures the Comparator 0 inputs and sets the value of the internal voltage reference. Table 130. Comparator 0 Control Register (CMP0) Bits 7 6 Field INPSEL INNSEL Reset 0 0 0 1 0 1 0 0 R/W R/W R/W R/W R/W R/W R/W R/W R/W Address 5 4 3 2 1 REFLVL 0 TIMTRG F90h Bit Description [7] INPSEL Signal Select for Positive Input 0 = GPIO pin used as positive comparator 0 input. 1 = Temperature sensor used as positive comparator 0 input. [6] INNSEL Signal Select for Negative Input 0 = Internal reference disabled, GPIO pin used as negative comparator 0 input. 1 = Internal reference enabled as negative comparator 0 input. PS025016-1013 PRELIMINARY Comparator Z8 Encore! XP® F1680 Series Product Specification 258 Bit Description (Continued) [5:2] REFLVL Comparator 0 Internal Reference Voltage Level This reference is independent of the ADC voltage reference. 0000 = 0.0 V 0001 = 0.2 V 0010 = 0.4 V 0011 = 0.6 V 0100 = 0.8 V 0101 = 1.0 V (Default) 0110 = 1.2 V 0111 = 1.4 V 1000 = 1.6 V 1001 = 1.8 V 1010–1111 = Reserved [1:0] Timer Trigger (COMPARATOR COUNTER MODE) TIMTRG 00 = Disable Timer Trigger. 01 = Comparator 0 output works as Timer 0 Trigger. 10 = Comparator 0 output works as Timer 1 Trigger. 11 = Comparator 0 output works as Timer 2 Trigger. 18.2.2. Comparator 1 Control Register The Comparator 1 Control Register (CMP1), shown in Table 131, configures the comparator 1 inputs and sets the value of the internal voltage reference. Table 131. Comparator 1 Control Register (CMP1) Bits 7 6 Field INPSEL INNSEL Reset 0 0 0 1 0 1 0 0 R/W R/W R/W R/W R/W R/W R/W R/W R/W Address 5 4 3 2 1 REFLVL 0 TIMTRG F91h Bit Description [7] INPSEL Signal Select for Positive Input 0 = GPIO pin used as positive comparator 1 input. 1 = Temperature sensor used as positive comparator 1 input. [6] INNSEL Signal Select for Negative Input 0 = Internal reference disabled, GPIO pin used as negative comparator 1 input. 1 = Internal reference enabled as negative comparator 1 input. PS025016-1013 PRELIMINARY Comparator Z8 Encore! XP® F1680 Series Product Specification 259 Bit Description (Continued) [5:2] REFLVL Comparator 1 Internal Reference Voltage Level This reference is independent of the ADC voltage reference. 0000 = 0.0 V 0001 = 0.2 V 0010 = 0.4 V 0011 = 0.6 V 0100 = 0.8 V 0101 = 1.0 V (Default) 0110 = 1.2 V 0111 = 1.4 V 1000 = 1.6 V 1001 = 1.8 V 1010–1111 = Reserved [1:0] Timer Trigger (Comparator Counter Mode) TIMTRG Enable/disable timer operation. 00 = Disable Timer Trigger. 01 = Comparator 1 output works as Timer 0 Trigger. 10 = Comparator 1 output works as Timer 1 Trigger. 11 = Comparator 1 output works as Timer 2 Trigger. PS025016-1013 PRELIMINARY Comparator Z8 Encore! XP® F1680 Series Product Specification 260 Chapter 19. Temperature Sensor The on-chip Temperature Sensor allows you to measure temperature on the die to an accuracy of roughly ±7° C over a range of –40° C to +105° C. Over a reduced range, the accuracy is significantly better. This block is a moderately accurate temperature sensor for low-power applications where high accuracy is not required. Uncalibrated accuracy is significantly worse, therefore the temperature sensor is not recommended for untrimmed use: • • • • On-chip temperature sensor ±7° C full-range accuracy for calibrated version ±1.5° C accuracy over the range of 20° C to 30° C Flash recalibration capability 19.1. Operation The on-chip temperature sensor is a Proportional To Absolute Temperature (PTAT) topology which provides for zero-point calibration. A pair of Flash option bytes contain the calibration data. The temperature sensor can be disabled by a bit in the Power Control Register 0 (see page 44) to reduce power consumption. The temperature sensor can be directly read by the ADC to determine the absolute value of its output. The temperature sensor output is also available as an input to the comparator for threshold type measurement determination. The accuracy of the sensor when used with the comparator is substantially less than when measured by the ADC. Maximum accuracy can be obtained by customer retrimming the sensor using an external reference and a high-precision external reference in the target application. During normal operation, the die undergoes heating that will cause a mismatch between the ambient temperature and that measured by the sensor. For best results, the XP device should be placed into STOP Mode for sufficient time such that the die and ambient temperatures converge (this time will be dependent on the thermal design of the system). The temperature sensor should be measured immediately after recovery from STOP Mode. The following two equations define the relationship between the ADC reading and the die temperature. In each equation, T is the temperature in degrees Celsius, and ADC is the 10bit compensated ADC value. Equation #1. If bit 2 of TEMPCALH calibration option byte is 0, then: T = (25/128) * (ADC + {TEMPCALH_bit1, TEMPCALH_bit0, TEMPCALL}) – 77 Equation #2. If bit 2 of TEMPCALH calibration option byte is 1, then: T = (25/128) * (ADC – {TEMPCALH_bit1, TEMPCALH_bit0, TEMPCALL}) –77 PS025016-1013 PRELIMINARY Temperature Sensor Z8 Encore! XP® F1680 Series Product Specification 261 In these two equations, TEMPCALH and TEMPCALL are a pair of Flash option bits containing the calibration data. For more details, see the discussion of TEMPCALH and TEMPCALL in the Flash Option Bits chapter on page 276. Note: The equations above are temporary test results of the Z8F1680 MCU, version A. The coefficient in the formula may change according to results from tests of version B. 19.1.1. Calibration The temperature sensor undergoes calibration during the manufacturing process and is maximally accurate only at 30° C. Accuracy decreases as measured temperatures move further from the calibration point. Because this sensor is an on-chip sensor, Zilog recommends that the user accounts for the difference between ambient and die temperatures when inferring ambient temperature conditions. PS025016-1013 PRELIMINARY Temperature Sensor Z8 Encore! XP® F1680 Series Product Specification 262 Chapter 20. Flash Memory The products in the Z8 Encore! XP F1680 Series feature either 24 KB (24576 bytes), 16 KB (16384 bytes) and 8 KB (8192 bytes) of nonvolatile Flash memory with read/write/ erase capability. The Flash memory can be programmed and erased in-circuit by either user code or through the On-Chip Debugger. The Flash memory array is arranged in pages with 512 bytes per page. The 512 byte page is the minimum Flash block size that can be erased. Each page is divided into 4 rows of 128 bytes. For program/data protection, Flash memory is also divided into sectors. In the Z8 Encore! XP F1680 Series, Flash memory is divided into 8 sectors which can be protected from programming and erase operation on a per sector basis. The first 2 bytes of the Flash program memory are used as Flash option bits. For more information about their operation, see the Flash Option Bits chapter on page 276. Table 132 lists the Flash memory configuration for each device in the Z8 Encore! XP F1680 Series. Table 132. Z8 Encore! XP F1680 Series Flash Memory Configurations Part Number Flash Size in Flash KB (Bytes) Pages Program Memory Addresses Flash Sector Size (bytes) Number of Sectors Pages per Sector Z8F2480 24 (24576) 48 0000h–5FFFh 3072 8 6 Z8F1680 16 (16384) 32 0000h–3FFFh 2048 8 4 Z8F0880 8 (8192) 16 0000h–1FFFh 1024 8 2 20.1. Flash Information Area The Flash Information Area is separate from Program Memory and is mapped to the address range FE00h to FFFFh. Not all these addresses are user-accessible. Factory trim values for the analog peripherals are stored in the Flash Information Area, and so are factory calibration data for the Temperature Sensor. Figures 51 through 53 display the Flash memory arrangement. PS025016-1013 PRELIMINARY Flash Memory Z8 Encore! XP® F1680 Series Product Specification 263 8KB Flash Program Memory Addresses 1FFFh Page 15 Page 14 Sector 7 1C00h Page 13 1BFFh Page 12 Sector 6 Page 11 1800h Page 10 17FFh 1FFFh 1DFFh 1BFFh 19FFh 17FFh 15FFh 13FFh Sector 5 1400h 13FFh 0C00h 0BFFh Sector 2 0800h 07FFh Page 3 Sector 1 0400h Page 2 03FFh Page 1 Sector 0 Page 0 0000h 07FFh 05FFh 03FFh 01FFh 0000h Figure 51. 8 KB Flash Memory Arrangement PS025016-1013 PRELIMINARY Flash Memory Z8 Encore! XP® F1680 Series Product Specification 264 16KB Flash Program Memory Addresses 3FFFh Page 31 3FFFh Page 30 Sector 7 3800h Page 29 37FFh Page 28 Sector 6 Page 27 3000h Page 26 2FFFh Sector 5 Page 25 2800h 27FFh Page 24 39FFh 37FFh 35FFh 33FFh 31FFh 2FFFh Page 7 Page 6 1800h 17FFh Page 5 Sector 2 0FFFh 0DFFh 0BFFh Page 4 1000h 0FFFh Page 3 Sector 1 0800h Page 2 07FFh Page 1 Sector 0 Page 0 0000h 05FFh 03FFh 01FFh 0000h Figure 52. 16 KB Flash Memory Arrangement PS025016-1013 PRELIMINARY Flash Memory Z8 Encore! XP® F1680 Series Product Specification 265 24KB Flash Program Memory Addresses 5FFFh Page 47 5FFFh Page 46 Sector 7 5400h Page 45 53FFh Page 44 Sector 6 Page 43 4800h Page 42 47FFh Sector 5 Page 41 3C00h 3BFFh Page 40 59FFh 57FFh 55FFh 53FFh 51FFh 4FFFh 2400h 23FFh Page 5 Sector 2 0BFFh Page 4 1800h 17FFh Page 3 Sector 1 0C00h Page 2 0BFFh Page 1 Sector 0 Page 0 0000h 05FFh 03FFh 01FFh 0000h Figure 53. 24 KB Flash Memory Arrangement 20.2. Operation The Flash Controller programs and erases Flash memory. The Flash Controller provides the proper Flash controls and timing for byte programming, Page Erase and Mass Erase of Flash memory. The Flash Controller contains several protection mechanisms to prevent accidental programming or erasure. These mechanisms operate on the page, sector and full-memory levels. The Flow Chart in Figure 54 displays basic Flash Controller operation. The sections that follow provide details about the various operations (Lock, Unlock, Byte Programming, Page Protect, Page Unprotect, Page Select Page Erase and Mass Erase) shown in Figure 54. PS025016-1013 PRELIMINARY Flash Memory Z8 Encore! XP® F1680 Series Product Specification 266 Reset Lock State 0 Write Page Select Register Write FCTL No 73h Yes Lock State 1 Write FCTL Writes to Page Select Register in Lock State 1 result in a return to Lock State 0 No 8Ch Yes Write Page Select Register No Page Select values match? Yes Yes Page in Protected Sector? Byte Program Write FCTL No Page Unlocked Program/Erase Enabled 95h Yes Page Erase No Figure 54. Flowchart: Flash Controller Operation PS025016-1013 PRELIMINARY Flash Memory Z8 Encore! XP® F1680 Series Product Specification 267 20.2.1. Flash Operation Timing Using Flash Frequency Registers Before performing either a program or erase operation on Flash memory, you must first configure the Flash frequency High and Low Byte registers. The Flash frequency registers allow programming and erasing of the Flash with system clock frequencies ranging from 32 kHz (32768 Hz) through 20 MHz. The Flash frequency High and Low Byte registers combine to form a 16-bit value, FFREQ, to control timing for flash program and erase operations. The 16-bit binary Flash frequency value must contain the system clock frequency (in kHz). This value is calculated using the following equation: System Clock Frequency (Hz) FFREQ[15:0] = ------------------------------------------------------------------------------1000 Caution: Flash programming and erasure are not supported for system clock frequencies below 32 kHz (32768 Hz) or above 20 MHz. The Flash Frequency High and Low Byte registers must be loaded with the correct value to ensure operation of the Z8 Encore! XP F1680 Series devices. 20.2.2. Flash Code Protection Against External Access The user code contained within Flash memory can be protected against external access with the On-Chip Debugger. Programming the FRP Flash option bit prevents reading of the user code with the On-Chip Debugger. For more details, see the Flash Option Bits chapter on page 276 and the On-Chip Debugger chapter on page 294. 20.2.3. Flash Code Protection Against Accidental Program and Erasure The Z8 Encore! XP F1680 Series provides several levels of protection against accidental program and erasure of the contents of Flash memory. This protection is provided by a combination of the Flash Option bits, the register locking mechanism, the page select redundancy and the sector level protection control of the Flash Controller. 20.2.3.1. Flash Code Protection Using the Flash Option Bits The FWP Flash option bit provides Flash Program Memory protection as listed in Table 133. For more details, see the Flash Option Bits chapter on page 276. PS025016-1013 PRELIMINARY Flash Memory Z8 Encore! XP® F1680 Series Product Specification 268 Table 133. Flash Code Protection Using the Flash Option Bit FWP Flash Code Protection Description 0 Programming and erasing disabled for all of Flash Program Memory. In user code programming, Page Erase and Mass Erase are all disabled. Mass Erase is available through the On-Chip Debugger. 1 Programming, Page Erase and Mass Erase are enabled for all of Flash Program Memory. 20.2.3.2. Flash Code Protection Using the Flash Controller At Reset, the Flash Controller locks to prevent accidental program or erasure of the contents of Flash memory. Follow the steps below to unlock the Flash Controller from user code: 1. Write the Page Select Register with the target page. 2. Write the first unlock command 73h to the Flash Control Register. 3. Write the second unlock command 8Ch to the Flash Control Register. 4. Rewrite the Page Select Register with the same page previously stored there.  If the two Page Select writes do not match, the controller reverts to a locked state. If the two writes match, the selected page becomes active. For details, see the flowchart in Figure 54 on page 266. Note: Byte Programming, Page Erase and Mass Erase will not be allowed if the FWP bit is cleared or if the page resides in a protected block. After unlocking a specific page, Byte Programing or Page Erase can be performed. At the conclusion of a Page Erase, the Flash Controller is automatically locked. To lock the Flash Controller after Byte Programming, write to the Flash Control Register with any value other than the Page Erase or Mass Erase comands. 20.2.3.3. Sector Based Flash Protection The final protection mechanism is implemented on a per-sector basis. The Flash memories of Z8 Encore! devices are divided into a maximum number of 8 sectors. A sector is 1/8 of the total size of Flash memory unless this value is smaller than the page size, in which case the sector and page sizes are equal. On the Z8 Encore! XP F1680 Series devices, the sector size is 3 KB, 2 KB or 1 KB depending on available on-chip Flash size of 24 KB, 16 KB and 8 KB. PS025016-1013 PRELIMINARY Flash Memory Z8 Encore! XP® F1680 Series Product Specification 269 The Flash Sector Protect Register can be configured to prevent sectors from being programmed or erased. After a sector is protected, it cannot be unprotected by user code. The Flash Sector Protect Register is cleared after reset and any previously written protection values is lost. User code must write this register in their initialization routine if they want to enable sector protection. The Flash Sector Protect Register shares its Register File address with the Page Select Register. The Flash Sector Protect Register is accessed by writing the Flash Control Register with 5Eh. After the Flash Sector Protect Register is selected, it can be accessed at the Page Select Register address. When user code writes the Flash Sector Protect Register, bits can only be set to 1. Thus, sectors can be protected, but not unprotected, via register write operations. Writing a value other than 5Eh to the Flash Control Register deselects the Flash Sector Protect Register and reenables access to the Page Select Register. code: 1. Write 00h to the Flash Control Register to reset the Flash Controller. 2. Write 5Eh to the Flash Control Register to select the Flash Sector Protect Register. 3. Read and/or write the Flash Sector Protect Register which is now at Register File address FF9h. 4. Write 00h to the Flash Control Register to return the Flash Controller to its reset state. The Sector Protect Register is initialized to 0 on Reset, putting each sector into an unprotected state. When a bit in the Sector Protect Register is written to 1, the corresponding sector can no longer be written or erased. After a bit of the Sector Protect Register has been set, it can not be cleared except by a System Reset. 20.2.4. Byte Programming Flash memory is enabled for byte programming on the active page after unlocking the Flash Controller. Erase the address(es) to be programmed using either the Page Erase or Mass Erase command prior to performing byte programming. An erased Flash byte contains all 1s (FFh). The programming operation can only be used to change bits from 1 to 0. To change a Flash bit (or multiple bits) from 0 to 1 requires execution of either the Page Erase or Mass Erase command. Byte programming can be accomplished using the On-Chip Debugger’s Write Memory command or eZ8 CPU execution of the LDC or LDCI instructions. For a description of the LDC and LDCI instructions, refer to the eZ8 CPU Core User Manual (UM0128), available for download at www.zilog.com. While the Flash Controller programs the contents of Flash memory, the eZ8 CPU idles but the system clock and on-chip peripherals continue to operate. After a byte is written, the page remains unlocked, allowing for subsequent writes to other bytes on the same page. To exit programming mode and lock Flash memory, write any value to the Flash Control Register except the Mass Erase or Page Erase commands. PS025016-1013 PRELIMINARY Flash Memory Z8 Encore! XP® F1680 Series Product Specification 270 Caution: The byte at each Flash memory address cannot be programmed (any bits written to 0) more than twice before an erase cycle occurs. 20.2.5. Page Erase The Flash memory can be erased one page (512 bytes) at a time. Page-erasing Flash memory sets all bytes in that page to the value FFh. The Flash Page Select register identifies the page to be erased. Only a page residing in an unprotected sector can be erased. With the Flash Controller unlocked, writing the value 95h to the Flash Control Register initiates the Page Erase operation on the active page. While the Flash Controller executes the Page Erase operation, the eZ8 CPU idles but the system clock and on-chip peripherals continue to operate. The eZ8 CPU resumes operation after the Page Erase operation completes. If the Page Erase operation is performed using the OCD, poll the Flash Status register to determine when the Page Erase operation is complete. When the Page Erase is complete, the Flash Controller returns to its locked state. 20.2.6. Mass Erase Flash memory can also be mass-erased using the Flash Controller, but only by using the On-Chip Debugger. Mass-erasing Flash memory sets all bytes to the value FFh. With the Flash Controller unlocked, writing the value 63h to the Flash Control Register initiates the Mass Erase operation. While the Flash Controller executes the Mass Erase operation, the eZ8 CPU idles but the system clock and on-chip peripherals continue to operate. Using the On-Chip Debugger, poll the Flash Status register to determine when the Mass Erase operation is complete. When the Mass Erase is complete, the Flash Controller returns to its locked state. 20.2.7. Flash Controller Bypass The Flash Controller can be bypassed and the control signals for Flash memory are brought out to the GPIO pins. Bypassing the Flash Controller allows faster row programming algorithms by controlling these Flash programming signals directly. Row programming is recommended for gang programming applications and large-volume customers who do not require in-circuit initial programming of Flash memory. Mass Erase and Page Erase operations are also supported when the Flash Controller is bypassed. For more information about bypassing the Flash Controller, please contact Zilog Technical Support. PS025016-1013 PRELIMINARY Flash Memory Z8 Encore! XP® F1680 Series Product Specification 271 20.2.8. Flash Controller Behavior in Debug Mode The following changes in behavior of the Flash Controller occur when the Flash Controller is accessed using the On-Chip Debugger: • • • • • The Flash Write Protect option bit is ignored • • The Page Select register can be written when the Flash Controller is unlocked The Flash Sector Protect register is ignored for programming and erase operations Programming operations are not limited to the page selected in the Page Select Register Bits in the Flash Sector Protect register can be written to 1 or 0 The second write of the Page Select register to unlock the Flash Controller is not necessary The Mass Erase command is enabled through the Flash Control Register Caution: For security reasons, the Flash controller allows only a single page to be opened for write/erase. When writing multiple Flash pages, the Flash controller must go through the unlock sequence again to select another page. 20.3. Flash Control Register Definitions This section defines the features of the following Flash Control registers. Flash Control Register: see page 271 Flash Status Register: see page 272 Flash Page Select Register: see page 273 Flash Sector Protect Register: see page 274 Flash Frequency High and Low Byte Registers: see page 274 20.3.1. Flash Control Register The Flash Controller must be unlocked using the Flash Control Register (see Table 134) before programming or erasing Flash memory. The Flash Controller is unlocked by writing to the Flash Page Select Register, then 73h 8Ch, sequentially, to the Flash Control Register, and finally again to the Flash Page Select Register with the same value as the previous write. When the Flash Controller is unlocked, Mass Erase or Page Erase can be initiated by writing the appropriate command to the FCTL. Erase applies only to the active page selected in the Flash Page Select Register. Mass Erase is enabled only through the PS025016-1013 PRELIMINARY Flash Memory Z8 Encore! XP® F1680 Series Product Specification 272 On-Chip Debugger. Writing an invalid value or an invalid sequence returns the Flash Controller to its locked state. The write-only Flash Control Register shares its Register File address with the read-only Flash Status Register. Table 134. Flash Control Register (FCTL) Bits 7 6 5 4 Field 3 2 1 0 FCMD Reset 0 0 0 0 0 0 0 0 R/W W W W W W W W W Address FF8h Bit Description [7:0] FCMD Flash Command 73h = First unlock command. 8Ch = Second unlock command. 95h = Page Erase command (must be third command in sequence to initiate Page Erase). 63h = Mass Erase command (must be third command in sequence to initiate Mass Erase). 5Eh = Enable Flash Sector Protect Register Access 20.3.2. Flash Status Register The Flash Status register (Table 135) indicates the current state of the Flash Controller. This register can be read at any time. The read-only Flash Status Register shares its Register File address with the write-only Flash Control Register. Table 135. Flash Status Register (FSTAT) Bits 7 Field 6 5 4 3 Program_status 2 1 0 FSTAT Reset 0 0 0 0 0 0 0 0 R/W R R R R R R R R Address Bit FF8h Description [7:6] Indicate the fail or success after Flash Write/Erase Program_ 00 = Success. status 10 = Success. 11 = Fail due to low power. 01 = Reserved. PS025016-1013 PRELIMINARY Flash Memory Z8 Encore! XP® F1680 Series Product Specification 273 Bit Description (Continued) [5:0] FSTAT Flash Controller Status 000000 = Flash Controller locked. 000001 = First unlock command received (73h written). 000010 = Second unlock command received (8Ch written). 000011 = Flash Controller unlocked. 000100 = Sector protect register selected. 001xxx = Program operation in progress. 010xxx = Page erase operation in progress. 100xxx = Mass erase operation in progress. 20.3.3. Flash Page Select Register The Flash Page Select Register, shown in Table 136, shares address space with the Flash Sector Protect Register. Unless the Flash controller was last written with 5Eh, writes to this address target the Flash Page Select Register. The register is used to select one of the Flash memory pages to be programmed or erased. Each Flash Page contains 512 bytes of Flash memory. During a Page Erase operation, all Flash memory having addresses with the most significant 7 bits provided by FPS[6:0] are chosen for program/erase operation. Table 136. Flash Page Select Register (FPS) Bits 7 Field INFO_EN Reset 0 0 0 0 R/W R/W R/W R/W R/W Address Bit 6 5 4 3 2 1 0 0 0 0 0 R/W R/W R/W R/W PAGE FF9h Description [7] Information Area Enable INFO_EN 0 = Information Area is not selected. 1 = Information Area is selected. The Information Area is mapped into the Program Memory address space at addresses FE00h through FFFFh. [6:0] PAGE Page Select This 7-bit field identifies the Flash memory page for Page Erase and page unlocking. Program Memory address[15:9] = PAGE[6:0]. • On Z8F2480 devices, the upper 1 bit must always be 0. • On Z8F1680 devices, the upper 2 bits must always be 0. • On Z8F0880 devices, the upper 3 bits must always be 0. PS025016-1013 PRELIMINARY Flash Memory Z8 Encore! XP® F1680 Series Product Specification 274 20.3.4. Flash Sector Protect Register The Flash Sector Protect Register is shared with the Flash Page Select Register. When the Flash Control Register (see page 271) is written with 5Eh, the next write to this address targets the Flash Sector Protect Register. In all other cases, it targets the Flash Page Select Register. This register selects one of the eight available Flash memory sectors to be protected. The reset state of each Sector Protect bit is an unprotected state. After a sector is protected by setting its corresponding register bit, it can only be unprotected (the register bit can only be cleared) by a System Reset. Please refer to Table 132 on page 262 and to Figures 51 through 53 to review how Flash memory is arranged by sector. Table 137. Flash Sector Protect Register (FPROT) Bits 7 6 5 4 3 2 1 0 Field SPROT7 SPROT6 SPROT5 SPROT4 SPROT3 SPROT2 SPROT1 SPROT0 Reset 0 0 0 0 0 0 0 0 R/W R/W R/W R/W R/W R/W R/W R/W R/W Address Bit FF9h Description [7:0] Sector Protection SPROTx • On Z8F2480 devices, each bit corresponds to a 3 KB Flash sector. • On Z8F1680 devices, each bit corresponds to a 2 KB Flash sector. • On Z8F0880 devices, each bit corresponds to a 1 KB Flash sector. 20.3.5. Flash Frequency High and Low Byte Registers The Flash Frequency High and Low Byte registers, shown in Tables 138 and 139, combine to form a 16-bit value, FFREQ, to control timing for Flash program and erase operations. The 16-bit binary Flash Frequency value must contain the system clock frequency (in kHz) and is calculated using the following equation: System Clock Frequency FFREQ[15:0] =  FFREQH[7:0],FFREQL[7:0]  = -----------------------------------------------------------------1000 Caution: Flash programming and erasure is not supported for system clock frequencies below 32 kHz or above 20 MHz. The Flash Frequency High and Low Byte registers must be loaded with the correct values to ensure proper operation of the device. PS025016-1013 PRELIMINARY Flash Memory Z8 Encore! XP® F1680 Series Product Specification 275 Table 138. Flash Frequency High Byte Register (FFREQH) Bits 7 6 5 4 Field 1 0 0 0 0 0 0 0 0 0 R/W R/W R/W R/W R/W R/W R/W R/W 1 0 Address Bit 2 FFREQH Reset R/W 3 FFAh Description [7:0] Flash Frequency High Byte FFREQH High byte of the 16-bit Flash Frequency value. Table 139. Flash Frequency Low Byte Register (FFREQL) Bits 7 6 5 4 3 Field FFREQL Reset 0 R/W R/W Address FFBh Bit 2 Description [7:0] Flash Frequency Low Byte FFREQL Low byte of the 16-bit Flash Frequency value. PS025016-1013 PRELIMINARY Flash Memory Z8 Encore! XP® F1680 Series Product Specification 276 Chapter 21. Flash Option Bits Programmable Flash option bits allow user configuration of certain aspects of Z8 Encore! XP F1680 Series MCU operation. The feature configuration data is stored in Flash program memory and are read during Reset. The features available for control through the Flash option bits include: • • • • Watchdog Timer time-out response selection–interrupt or System Reset • VBO configuration-always enabled or disabled during STOP Mode to reduce STOP Mode power consumption • • LVD voltage threshold selection • Factory trimming information for the IPO and Temperature Sensor Watchdog Timer enabled at Reset The ability to prevent unwanted read access to user code in Program Memory The ability to prevent accidental programming and erasure of all or a portion of the user code in Program Memory Oscillator mode selection for high, medium and low-power crystal oscillators or an external RC oscillator 21.1. Operation This section describes the types of option bits and their configuration in the Option Configuration registers. 21.1.1. Option Bit Configuration by Reset Each time the Flash option bits are programmed or erased, the device must be Reset for the change to take effect. During any Reset operation (System Reset or Stop Mode Recovery), the Flash option bits are automatically read from Flash Program Memory and written to the Option Configuration registers. These Option Configuration registers control operation of the devices within the Z8 Encore! XP F1680 Series MCU. Option bit control is established before the device exits Reset and the eZ8 CPU begins code execution. The Option Configuration registers are not part of the Register File and are not accessible for read or write access. PS025016-1013 PRELIMINARY Flash Option Bits Z8 Encore! XP® F1680 Series Product Specification 277 21.1.2. Option Bit Types This section describes the User, Trim and Calibration option bit types. 21.1.2.1. User Option Bits The user option bits are contained in the first two bytes of Program Memory. User access to these bits has been provided because these locations contain application-specific device configurations. The information contained here is lost when page 0 of the Program Memory is erased. 21.1.2.2. Trim Option Bits The trim option bits are contained in the Flash memory information page. These bits are factory programmed values required to optimize the operation of onboard analog circuitry and cannot be permanently altered by the user. Program Memory can be erased without endangering these values. It is possible to alter working values of these bits by accessing the Trim Bit Address and Data registers, but these working values are lost after a power loss. There are 32 bytes of trim data. To modify one of these values the user code must first write a value between 00h and 1Fh into the Trim Bit Address Register. The next write to the Trim Bit Data Register changes the working value of the target trim data byte. Reading the trim data requires the user code to write a value between 00h and 1Fh into the Trim Bit Address Register. The next read from the Trim Bit Data Register returns the working value of the target trim data byte. Note: The trim address ranges from information address 20-3F only. The remainder of the information page is not accessible via the trim bit address and data registers. 21.1.2.3. Calibration Option Bits The calibration option bits are also contained in the information page. These bits are factory programmed values intended for use in software correcting the device’s analog performance. To read these values, the user code must employ the LDC instruction to access the information area of the address space as defined in the Flash Information Area section on page 21. The following code example shows how to read the calibration data from the Flash Information Area. ; get value at info address 60 (FE60h) ldx FPS, #%80 ; enable access to flash info page ld R0, #%FE PS025016-1013 PRELIMINARY Flash Option Bits Z8 Encore! XP® F1680 Series Product Specification 278 ld R1, #%60 ldc R2, @RR0 ; R2 now contains the calibration value 21.2. Flash Option Bit Control Register Definitions This section defines the features of the following Flash Option Bit Control registers. User Option Bits: see page 278 Trim Bit Data Option Bits: see page 281 Trim Bit Address Option Bits: see page 281 Trim Bit Address Space: see page 282 Zilog Calibration Option Bits: see page 289 21.2.1. User Option Bits The first two bytes of Flash program memory, at addresses 0000h and 0001h, are reserved for the user-programmable Flash option bits, as shown in Tables 140 and 141. Table 140. Flash Option Bits at Program Memory Address 0000h Bits Field 7 6 WDT_RES WDT_AO Reset R/W 5 4 OSC_SEL[1:0] 3 2 1 0 VBO_AO FRP PRAM_M FWP U U U U U U U U R/W R/W R/W R/W R/W R/W R/W R/W Address Program Memory 0000h Note: U = Unchanged by Reset. R/W = Read/Write. Bit Description [7] WDT_RES Watchdog Timer Reset 0 = Watchdog Timer time-out generates an interrupt request. Interrupts must be globally enabled for the eZ8 CPU to acknowledge the interrupt request. 1 = Watchdog Timer time-out causes a System Reset. This setting is the default for unprogrammed (erased) Flash. [6] WDT_AO Watchdog Timer Always ON 0 = Watchdog Timer is automatically enabled upon application of system power. Watchdog Timer cannot be disabled. 1 = Watchdog Timer is enabled upon execution of the WDT instruction. After it is enabled, the Watchdog Timer can only be disabled by a Reset or Stop Mode Recovery. This setting is the default for unprogrammed (erased) Flash. PS025016-1013 PRELIMINARY Flash Option Bits Z8 Encore! XP® F1680 Series Product Specification 279 Bit Description (Continued) [5:4] Oscillator Mode Selection OSC_SEL[1:0] 00 = On-chip oscillator configured for use with external RC networks or external clock input (