AT89C5130A-S3SUM

Features • 80C52X2 Core (6 Clocks per Instruction) – Maximum Core Frequency 48 MHz in X1 Mode, 24 MHz in X2 Mode – Dual Data Pointer – Full-duplex Enhanced UART (EUART) – Three 16-bit Timer/Counters: T0, T1 and T2 – 256 Bytes of Scratchpad RAM 16/32-Kbyte On-chip Flash EEPROM In-System Programming through USB – Byte and Page (128 bytes) Erase and Write – 100k Write Cycles 3-KbyteFlash EEPROM for Bootloader – Byte and Page (128 bytes) Erase and Write – 100k Write Cycles 1-Kbyte EEPROM Data ( – Byte and Page (128 bytes) Erase and Write – 100k Write Cycles On-chip Expanded RAM (ERAM): 1024 Bytes Integrated Power Monitor (POR/PFD) to Supervise Internal Power Supply USB 1.1 and 2.0 Full Speed Compliant Module with Interrupt on Transfer Completion – Endpoint 0 for Control Transfers: 32-byte FIFO – 6 Programmable Endpoints with In or Out Directions and with Bulk, Interrupt or Isochronous Transfers • Endpoint 1, 2, 3: 32-byte FIFO • Endpoint 4, 5: 2 x 64-byte FIFO with Double Buffering (Ping-pong Mode) • Endpoint 6: 2 x 512-byte FIFO with Double Buffering (Ping-pong Mode) – Suspend/Resume Interrupts – 48 MHz PLL for Full-speed Bus Operation – Bus Disconnection on Microcontroller Request 5 Channels Programmable Counter Array (PCA) with 16-bit Counter, High-speed Output, Compare/Capture, PWM and Watchdog Timer Capabilities Programmable Hardware Watchdog Timer (One-time Enabled with Reset-out): 100 ms to 3s at 8 MHz Keyboard Interrupt Interface on Port P1 (8 Bits) TWI (Two Wire Interface) 400Kbit/s SPI Interface (Master/Slave Mode) 34 I/O Pins 4 Direct-drive LED Outputs with Programmable Current Sources: 2-6-10 mA Typical 4-level Priority Interrupt System (11 sources) Idle and Power-down Modes 0 to 24 MHz On-chip Oscillator with Analog PLL for 48 MHz Synthesis Industrial Temperature Range Extended Range Power Supply: 2.7V to 5.5V (3.3V to 5.5V required for USB) Packages: PLCC52, VQFP64, QFN32 • • • 8-bit Flash Microcontroller with Full Speed USB Device AT89C5130A-M AT89C5131A-M • • • • • • • • • • • • • • • • 1. Description AT89C5130A/31A-M is a high-performance Flash version of the 80C51 single-chip 8-bit microcontrollers with full speed USB functions. AT89C5130A/31A-M features a full-speed USB module compatible with the USB specifications Version 1.1 and 2.0. This module integrates the USB transceivers with a 3.3V voltage regulator and the Serial Interface Engine (SIE) with Digital Phase Locked Loop and 48 MHz clock recovery. USB Event detection logic (Reset and Suspend/Resume) and FIFO buffers supporting the mandatory control Endpoint (EP0) and up to 6 versatile Endpoints (EP1/EP2/EP3/EP4/EP5/EP6) with minimum software overhead are also part of the USB module. AT89C5130A/31A-M retains the features of the Atmel 80C52 with extended Flash capacity (16/32-Kbytes), 256 bytes of internal RAM, a 4-level interrupt system, two 16-bit timer/counters (T0/T1), a full duplex enhanced UART (EUART) and an on-chip oscillator. In addition, AT89C5130A/31A-M has an on-chip expanded RAM of 1024 bytes (ERAM), a dual data pointer, a 16-bit up/down Timer (T2), a Programmable Counter Array (PCA), up to 4 programmable LED current sources, a programmable hardware watchdog and a power-on reset. AT89C5130A/31A-M has two software-selectable modes of reduced activity for further reduction in power consumption. In the idle mode the CPU is frozen while the timers, the serial ports and the interrupt system are still operating. In the power-down mode the RAM is saved, the peripheral clock is frozen, but the device has full wake-up capability through USB events or external interrupts. 2 AT89C5130A/31A-M 4337K–USB–04/08 AT89C5130A/31A-M 2. Block Diagram MISO MOSI T2EX VDD VSS CEX SCK AVDD SS RxD TxD T2 SDA ECI SCL (2) (2) XTAL1 XTAL2 EEPROM RAM 256x8 ERAM 1Kx8 (1) (1) (1) (1) (3) (3) (1) (1) (1) (1) EUART + BRG 16/32Kx8Flash 4Kx8 PCA Timer2 TWI SPI ALE PSEN CPU C51 CORE EA RD WR (2) (2) Timer 0 Timer 1 INT Ctrl Parallel I/O Ports & Ext. Bus Port 0 Port 1 Port 2 Port 3 Port 4 Key Watch USB Board Dog Regulator VREF (2) (2) RST T0 T1 (2) (2) INT0 INT1 AVSS P1 P2 P0 P3 P4 KIN [0..7] Notes: 1. Alternate function of Port 1 2. Alternate function of Port 3 3. Alternate function of Port 4 D+ D- 3 4337K–USB–04/08 3. Pinout Description 3.1 Pinout Figure 3-1. AT89C5130A/31A-M 52-pin PLCC Pinout P1.7/CEX4/KIN7/MOSI P1.5/CEX2/KIN5/MISO P1.6/CEX3/KIN6/SCK P1.1/T2EX/KIN1/SS P1.4/CEX1/KIN4 P1.3/CEX0/KIN3 P1.2/ECI/KIN2 7 P4.1/SDA P2.3/A11 P2.4/A12 P2.5/A13 XTAL2 XTAL1 P2.6/A14 P2.7/A15 VDD AVDD UCAP AVSS P3.0/RxD 8 9 10 11 12 13 14 15 16 17 18 19 20 6 54 3 2 1 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 NC P0.1/AD1 P0.2/AD2 RST P0.3/AD3 VSS PLCC52 P1.0/T2/KIN0 P0.4/AD4 P3.7/RD/LED3 P0.5/AD5 P0.6/AD6 P0.7/AD7 P3.6/WR/LED2 NC P3.5/T1/LED1 P4.0/SCL 21 22 23 24 25 26 27 28 29 30 31 32 33 D+ VREF UVSS ALE DP3.2/INT0 PSEN P3.1/TxD P3.3/INT1/LED0 P3.4/T0 PLLF 4 AT89C5130A/31A-M 4337K–USB–04/08 EA P0.0/AD0 P2.2/A10 P2.1/A9 P2.0/A8 AT89C5130A/31A-M Figure 3-2. AT89C5130A/31A-M 64-pin VQFP Pinout P4.1/SDA P4.0/SCL P1.7/CEX4/KIN7/MOSI P1.5/CEX2/KIN5/MISO P1.6/CEX3/KIN6/SCK P1.1/T2EX/KIN1/SS P1.3/CEX0/KIN3 P1.4/CEX1/KIN4 P1.2/ECI/KIN2 P1.0/T2/KIN0 P0.0/AD0 P2.2/A10 P2.1/A9 P2.0/A8 NC 64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 NC P2.3/A11 P2.4/A12 P2.5/A13 XTAL2 XTAL1 P2.6/A14 P2.7/A15 VDD AVDD UCAP AVSS NC P3.0/RxD NC NC 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 48 47 46 45 44 43 42 41 40 39 38 37 36 35 NC NC P0.1/AD1 P0.2/AD2 RST P0.3/AD3 VSS NC VQFP64 NC P0.4/AD4 P3.7/RD/LED3 P0.5/AD5 P0.6/AD6 P0.7/AD7 P3.6/WR/LED2 34 NC 33 NC 17 18 19 20 21 22 23 24 25 26 27 28 29 30 3132 P3.3/INT1/LED0 P3.5/T1/LED1 NC NC NC ALE PSEN P3.1/TxD P3.2/INT0 P3.4/T0 VREF UVSS PLLF EA D- D+ 5 4337K–USB–04/08 Figure 3-3. AT89C5130A/31A-M 32-pin QFN Pinout P1.7/CEX4/KIN7/MOSI P1.5/CEX2/KIN5/MISO P1.6/CEX3/KIN6/SCK P1.1/T2EX/KIN1/SS 24 23 22 21 20 19 18 17 9 10 11 12 13 14 15 16 D+ VREF UVSS DP3.2/INT0 P3.1/TxD P3.3/INT1/LED0 P3.4/T0 P1.4/CEX1/KIN4 P1.3/CEX0/KIN3 32 31 30 29 28 27 26 25 P4.1/SDA XTAL2 XTAL1 VDD UCAP AVSS P3.0/RxD PLLF 1 2 3 4 5 6 7 8 P1.0/T2/KIN0 RST NC VSS NC QFN32 P1.2/ECI/KIN2 P4.0/SCL P3.7/RD/LED3 P3.6/WR/LED2 P3.5/T1/LED1 Note : The metal plate can be connected to Vss 3.2 Signals All the AT89C5130A/31A-M signals are detailed by functionality on Table 3-1 through Table 312. Table 3-1. Keypad Interface Signal Description Type Description Keypad Input Lines Holding one of these pins high or low for 24 oscillator periods triggers a keypad interrupt if enabled. Held line is reported in the KBCON register. Alternate Function Signal Name KIN[7:0) I P1[7:0] Table 3-2. Programmable Counter Array Signal Description Signal Name ECI Type I Description External Clock Input Alternate Function P1.2 6 AT89C5130A/31A-M 4337K–USB–04/08 AT89C5130A/31A-M Signal Name Type Description Capture External Input CEX[4:0] I/O Compare External Output Alternate Function P1.3 P1.4 P1.5 P1.6 P1.7 Table 3-3. Serial I/O Signal Description Type I O Description Serial Input Port Serial Output Port Alternate Function P3.0 P3.1 Signal Name RxD TxD Table 3-4. Timer 0, Timer 1 and Timer 2 Signal Description Type Description Timer 0 Gate Input INT0 serves as external run control for timer 0, when selected by GATE0 bit in TCON register. INT0 I External Interrupt 0 INT0 input set IE0 in the TCON register. If bit IT0 in this register is set, bits IE0 are set by a falling edge on INT0. If bit IT0 is cleared, bits IE0 is set by a low level on INT0. Timer 1 Gate Input INT1 serves as external run control for Timer 1, when selected by GATE1 bit in TCON register. INT1 I External Interrupt 1 INT1 input set IE1 in the TCON register. If bit IT1 in this register is set, bits IE1 are set by a falling edge on INT1. If bit IT1 is cleared, bits IE1 is set by a low level on INT1. Timer Counter 0 External Clock Input When Timer 0 operates as a counter, a falling edge on the T0 pin increments the count. Timer/Counter 1 External Clock Input When Timer 1 operates as a counter, a falling edge on the T1 pin increments the count. Timer/Counter 2 External Clock Input Timer/Counter 2 Clock Output Timer/Counter 2 Reload/Capture/Direction Control Input P3.3 P3.2 Alternate Function Signal Name T0 I P3.4 T1 I P3.5 T2 T2EX I O I P1.0 P1.1 7 4337K–USB–04/08 Table 3-5. LED Signal Description Type Description Direct Drive LED Output These pins can be directly connected to the Cathode of standard LEDs without external current limiting resistors. The typical current of each output can be programmed by software to 2, 6 or 10 mA. Several outputs can be connected together to get higher drive capabilities. Alternate Function P3.3 P3.5 P3.6 P3.7 Signal Name LED[3:0] O Table 3-6. TWI Signal Description Type Description SCL: TWI Serial Clock SCL output the serial clock to slave peripherals. SCL input the serial clock from master. SDA: TWI Serial Data SCL is the bidirectional TWI data line. Alternate Function Signal Name SCL I/O P4.0 SDA I/O P4.1 Table 3-7. SPI Signal Description Type I/O Description SS: SPI Slave Select MISO: SPI Master Input Slave Output line MISO I/O When SPI is in master mode, MISO receives data from the slave peripheral. When SPI is in slave mode, MISO outputs data to the master controller. SCK: SPI Serial Clock SCK outputs clock to the slave peripheral or receive clock from the master MOSI: SPI Master Output Slave Input line When SPI is in master mode, MOSI outputs data to the slave peripheral. When SPI is in slave mode, MOSI receives data from the master controller P1.7 P1.5 Alternate Function P1.1 Signal Name SS SCK I/O P1.6 MOSI I/O 8 AT89C5130A/31A-M 4337K–USB–04/08 AT89C5130A/31A-M Table 3-8. Ports Signal Description Type Description Port 0 P0 is an 8-bit open-drain bidirectional I/O port. Port 0 pins that have 1s written to them float and can be used as high impedance inputs. To avoid any parasitic current consumption, Floating P0 inputs must be pulled to VDD or VSS. Alternate Function Signal Name P0[7:0] I/O AD[7:0] P1[7:0] I/O Port 1 P1 is an 8-bit bidirectional I/O port with internal pull-ups. KIN[7:0] T2 T2EX ECI CEX[4:0] P2[7:0] I/O Port 2 P2 is an 8-bit bidirectional I/O port with internal pull-ups. A[15:8] LED[3:0] RxD TxD P3[7:0] I/O Port 3 P3 is an 8-bit bidirectional I/O port with internal pull-ups. INT0 INT1 T0 T1 WR RD SCL SDA P4[1:0] I/O Port 4 P4 is an 2-bit open drain port. Table 3-9. Clock Signal Description Type Description Input to the on-chip inverting oscillator amplifier To use the internal oscillator, a crystal/resonator circuit is connected to this pin. If an external oscillator is used, its output is connected to this pin. Output of the on-chip inverting oscillator amplifier To use the internal oscillator, a crystal/resonator circuit is connected to this pin. If an external oscillator is used, leave XTAL2 unconnected. PLL Low Pass Filter input Receive the RC network of the PLL low pass filter. Alternate Function Signal Name XTAL1 I - XTAL2 O - PLLF I - 9 4337K–USB–04/08 Table 3-10. USB Signal Description Type I/O Description USB Data + signal Set to high level under reset. USB Data - signal Set to low level under reset. USB Reference Voltage Connect this pin to D+ using a 1.5 kΩ resistor to use the Detach function. Alternate Function - Signal Name D+ D- I/O - VREF O - Table 3-11. System Signal Description Type I/O I/O Description Multiplexed Address/Data LSB for external access Data LSB for Slave port access (used for 8-bit and 16-bit modes) Address Bus MSB for external access Read Signal Read signal asserted during external data memory read operation. Control input for slave port read access cycles. Write Signal Write signal asserted during external data memory write operation. Control input for slave write access cycles. Reset Input Holding this pin low for 64 oscillator periods while the oscillator is running resets the device. The Port pins are driven to their reset conditions when a voltage lower than VIL is applied, whether or not the oscillator is running. This pin has an internal pull-up resistor which allows the device to be reset by connecting a capacitor between this pin and VSS. Asserting RST when the chip is in Idle mode or Power-down mode returns the chip to normal operation. This pin is tied to 0 for at least 12 oscillator periods when an internal reset occurs ( hardware watchdog or power monitor). Address Latch Enable Output The falling edge of ALE strobes the address into external latch. This signal is active only when reading or writing external memory using MOVX instructions. Program Strobe Enable / Hardware conditions Input for ISP Used as input under reset to detect external hardware conditions of ISP mode. External Access Enable EA I This pin must be held low to force the device to fetch code from external program memory starting at address 0000h. Alternate Function P0[7:0] P2[7:0] Signal Name AD[7:0] A[15:8] RD I/O P3.7 WR I/O P3.6 RST O - ALE O - PSEN I/O - Table 3-12. Power Signal Description Type GND Description Analog Ground AVSS is used to supply the on-chip PLL and the USB PAD. Alternate Function - Signal Name AVSS 10 AT89C5130A/31A-M 4337K–USB–04/08 AT89C5130A/31A-M Table 3-12. Power Signal Description (Continued) Type PWR Description Analog Supply Voltage AVDD is used to supply the on-chip PLL and the USB PAD. Digital Ground VSS is used to supply the buffer ring and the digital core. USB Digital Ground UVSS is used to supply the USB pads. USB Pad Power Capacitor UCAP must be connect to an external capacitor for USB pad power supply (for typical application see Figure 4-1 on page 12) Digital Supply Voltage VDD is used to supply the buffer ring on all versions of the device. It is also used to power the on-chip voltage regulator of the Standard versions or the digital core of the Low Power versions. USB pull-up Controlled Output VREF O VREF is used to control the USB D+ 1.5 kΩ pull up. The Vref output is in high impedance when the bit DETACH is set in the USBCON register. Alternate Function Signal Name AVDD VSS GND - UVSS GND - UCAP PWR - VDD PWR - 11 4337K–USB–04/08 4. Typical Application 4.1 Recommended External components All the external components described in the figure below must be implemented as close as possible from the microcontroller package. The following figure represents the typical wiring schematic. Figure 4-1. Typical Application VDD 100nF VSS 4.7µF VSS VSS 100nF VDD AVDD VDD USB VBUS D+ DGND VSS 1.5K VRef AT89C5130A/31A-M 27R 27R D+ DUVSS XTAL1 UCAP 22pF Q 22pF 1µF +20% VSS VSS PLLF 2.2nF 100R 10nF VSS VSS VSS XTAL2 AVSS VSS 12 AT89C5130A/31A-M 4337K–USB–04/08 AT89C5130A/31A-M 4.2 PCB Recommandations Figure 4-2. USB Pads Components must be close to the microcontroller Wires must be routed in Parallel and must be as short as possible VRef D+ DUSB Connector If possible, isolate D+ and D- signals from other signals with ground wires Figure 4-3. USB PLL AVss PLLF Components must be C1 microcontroller Isolate filter components with a ground wire R C2 close to the 13 4337K–USB–04/08 5. Clock Controller 5.1 Introduction The AT89C5130A/31A-M clock controller is based on an on-chip oscillator feeding an on-chip Phase Lock Loop (PLL). All the internal clocks to the peripherals and CPU core are generated by this controller. The AT89C5130A/31A-M X1 and X2 pins are the input and the output of a single-stage on-chip inverter (see Figure 5-1) that can be configured with off-chip components as a Pierce oscillator (see Figure 5-2). Value of capacitors and crystal characteristics are detailed in the section “DC Characteristics”. The X1 pin can also be used as input for an external 48 MHz clock. The clock controller outputs three different clocks as shown in Figure 5-1: • a clock for the CPU core • a clock for the peripherals which is used to generate the Timers, PCA, WD, and Port sampling clocks • a clock for the USB controller These clocks are enabled or disabled depending on the power reduction mode as detailed in Section “Power Management”, page 155. Figure 5-1. Oscillator Block Diagram ÷2 0 1 Peripheral Clock CPU Core Clock X2 CKCON.0 IDL PCON.0 X1 PLL 0 1 USB Clock X2 EXT48 PLLCON.2 PD PCON.1 5.2 Oscillator Two types of clock sources can be used for CPU: • Crystal oscillator on X1 and X2 pins: Up to 32 MHz (Amplifier Bandwidth) • External clock on X1 pin: Up to 48MHz 14 AT89C5130A/31A-M 4337K–USB–04/08 AT89C5130A/31A-M In order to optimize the power consumption, the oscillator inverter is inactive when the PLL output is not selected for the USB device. Figure 5-2. Crystal Connection X1 C1 Q C2 VSS X2 5.3 5.3.1 PLL PLL Description The AT89C5130A/31A-M PLL is used to generate internal high frequency clock (the USB Clock) synchronized with an external low-frequency (the Peripheral Clock). The PLL clock is used to generate the USB interface clock. Figure 5-3 shows the internal structure of the PLL. The PFLD block is the Phase Frequency Comparator and Lock Detector. This block makes the comparison between the reference clock coming from the N divider and the reverse clock coming from the R divider and generates some pulses on the Up or Down signal depending on the edge position of the reverse clock. The PLLEN bit in PLLCON register is used to enable the clock generation. When the PLL is locked, the bit PLOCK in PLLCON register (see Figure 5-3) is set. The CHP block is the Charge Pump that generates the voltage reference for the VCO by injecting or extracting charges from the external filter connected on PLLF pin (see Figure 5-4). Value of the filter components are detailed in the Section “DC Characteristics”. The VCO block is the Voltage Controlled Oscillator controlled by the voltage VREF produced by the charge pump. It generates a square wave signal: the PLL clock. Figure 5-3. PLL Block Diagram and Symbol PLLCON.1 PLLF PLLEN N divider OSC CLOCK N3:0 Up PFLD Down PLOCK PLLCON.0 CHP Vref VCO USB Clock R divider R3:0 USB CLOCK OSC clk × ( R + 1 ) USBclk = ---------------------------------------------N+1 USB Clock Symbol 15 4337K–USB–04/08 Figure 5-4. PLL Filter Connection PLLF R C1 VSS VSS C2 The typical values are: R = 100 Ω, C1 = 10 nf, C2 = 2.2 nF. 5.3.2 PLL Programming The PLL is programmed using the flow shown in Figure 5-5. As soon as clock generation is enabled user must wait until the lock indicator is set to ensure the clock output is stable. Figure 5-5. PLL Programming Flow PLL Programming Configure Dividers N3:0 = xxxxb R3:0 = xxxxb Enable PLL PLLEN = 1 PLL Locked? LOCK = 1? 5.3.3 Divider Values To generate a 48 MHz clock using the PLL, the divider values have to be configured following the oscillator frequency. The typical divider values are shown in Table 5-1. Table 5-1. Typical Divider Values Oscillator Frequency 3 MHz 6 MHz 8 MHz 12 MHz 16 MHz 18 MHz 20 MHz 24 MHz R+1 16 8 6 4 3 8 12 2 N+1 1 1 1 1 1 3 5 1 PLLDIV F0h 70h 50h 30h 20h 72h B4h 10h 16 AT89C5130A/31A-M 4337K–USB–04/08 AT89C5130A/31A-M Oscillator Frequency 32 MHz 40 MHz R+1 3 12 N+1 2 10 PLLDIV 21h B9h 5.4 Registers Table 5-2. CKCON0 (S:8Fh) Clock Control Register 0 7 TWIX2 6 WDX2 5 PCAX2 4 SIX2 3 T2X2 2 T1X2 1 T0X2 0 X2 Bit Bit Number Mnemonic Description TWI Clock This control bit is validated when the CPU clock X2 is set. When X2 is low, this bit has no effect. Clear to select 6 clock periods per peripheral clock cycle. Set to select 12 clock periods per peripheral clock cycle. Watchdog Clock This control bit is validated when the CPU clock X2 is set. When X2 is low, this bit has no effect. Clear to select 6 clock periods per peripheral clock cycle. Set to select 12 clock periods per peripheral clock cycle. Programmable Counter Array Clock This control bit is validated when the CPU clock X2 is set. When X2 is low, this bit has no effect. Clear to select 6 clock periods per peripheral clock cycle. Set to select 12 clock periods per peripheral clock cycle. Enhanced UART Clock (Mode 0 and 2) This control bit is validated when the CPU clock X2 is set. When X2 is low, this bit has no effect. Clear to select 6 clock periods per peripheral clock cycle. Set to select 12 clock periods per peripheral clock cycle. Timer2 Clock This control bit is validated when the CPU clock X2 is set. When X2 is low, this bit has no effect. Clear to select 6 clock periods per peripheral clock cycle. Set to select 12 clock periods per peripheral clock cycle. Timer1 Clock This control bit is validated when the CPU clock X2 is set. When X2 is low, this bit has no effect. Clear to select 6 clock periods per peripheral clock cycle. Set to select 12 clock periods per peripheral clock cycle. Timer0 Clock This control bit is validated when the CPU clock X2 is set. When X2 is low, this bit has no effect. Clear to select 6 clock periods per peripheral clock cycle. Set to select 12 clock periods per peripheral clock cycle. System Clock Control bit Clear to select 12 clock periods per machine cycle (STD mode, FCPU = FPER = FOSC/2). Set to select 6 clock periods per machine cycle (X2 mode, FCPU = FPER = FOSC). 7 TWIX2 6 WDX2 5 PCAX2 4 SIX2 3 T2X2 2 T1X2 1 T0X2 0 X2 17 4337K–USB–04/08 Reset Value = 0000 0000b Table 5-3. CKCON1 (S:AFh) Clock Control Register 1 7 6 5 4 3 2 1 0 SPIX2 Bit Bit Number Mnemonic Description 7-1 Reserved The value read from this bit is always 0. Do not set this bit. SPI Clock This control bit is validated when the CPU clock X2 is set. When X2 is low, this bit has no effect. Clear to select 6 clock periods per peripheral clock cycle. Set to select 12 clock periods per peripheral clock cycle. 0 SPIX2 Reset Value = 0000 0000b Table 5-4. PLLCON (S:A3h) PLL Control Register 7 6 5 4 3 2 EXT48 1 PLLEN 0 PLOCK Bit Bit Number Mnemonic Description 7-3 Reserved The value read from this bit is always 0. Do not set this bit. External 48 MHz Enable Bit Set this bit to bypass the PLL and disable the crystal oscillator. Clear this bit to select the PLL output as USB clock and to enable the crystal oscillator. PLL Enable Bit Set to enable the PLL. Clear to disable the PLL. PLL Lock Indicator Set by hardware when PLL is locked. Clear by hardware when PLL is unlocked. 2 EXT48 1 PLLEN 0 PLOCK Reset Value = 0000 0000b Table 5-5. PLLDIV (S:A4h) PLL Divider Register 7 R3 6 R2 5 R1 4 R0 3 N3 2 N2 1 N1 0 N0 18 AT89C5130A/31A-M 4337K–USB–04/08 AT89C5130A/31A-M Bit Bit Number Mnemonic Description 7-4 3-0 R3:0 N3:0 PLL R Divider Bits PLL N Divider Bits Reset Value = 0000 0000 19 4337K–USB–04/08 6. SFR Mapping The Special Function Registers (SFRs) of the AT89C5130A/31A-M fall into the following categories: • C51 core registers: ACC, B, DPH, DPL, PSW, SP • I/O port registers: P0, P1, P2, P3, P4 • Timer registers: T2CON, T2MOD, TCON, TH0, TH1, TH2, TMOD, TL0, TL1, TL2, RCAP2L, RCAP2H • Serial I/O port registers: SADDR, SADEN, SBUF, SCON • PCA (Programmable Counter Array) registers: CCON, CMOD, CCAPMx, CL, CH, CCAPxH, CCAPxL (x: 0 to 4) • Power and clock control registers: PCON • Hardware Watchdog Timer registers: WDTRST, WDTPRG • Interrupt system registers: IEN0, IPL0, IPH0, IEN1, IPL1, IPH1 • Keyboard Interface registers: KBE, KBF, KBLS • LED register: LEDCON • Two Wire Interface (TWI) registers: SSCON, SSCS, SSDAT, SSADR • Serial Port Interface (SPI) registers: SPCON, SPSTA, SPDAT • USB registers: Uxxx (17 registers) • PLL registers: PLLCON, PLLDIV • BRG (Baud Rate Generator) registers: BRL, BDRCON • Flash register: FCON (FCON access is reserved for the Flash API and ISP software) • EEPROM register: EECON • Others: AUXR, AUXR1, CKCON0, CKCON1 20 AT89C5130A/31A-M 4337K–USB–04/08 AT89C5130A/31A-M The table below shows all SFRs with their address and their reset value. Table 6-1. Bit Addressable 0/8 F8h UEPINT 0000 0000 B 0000 0000 1/9 CH 0000 0000 LEDCON 0000 0000 CL 0000 0000 ACC 0000 0000 CCON 00X0 0000 PSW 0000 0000 T2CON 0000 0000 P4 XXXX 1111 IPL0 X000 000 P3 1111 1111 IEN0 0000 0000 P2 1111 1111 SCON 0000 0000 P1 1111 1111 TCON 0000 0000 P0 1111 1111 0/8 TMOD 0000 0000 SP 0000 0111 1/9 TL0 0000 0000 DPL 0000 0000 2/A SBUF XXXX XXXX SADEN 0000 0000 IEN1 X0XX X000 SADDR 0000 0000 AUXR1 XXXX X0X0 BRL 0000 0000 PLLCON XXXX XX00 BDRCON XXX0 0000 SSCON 0000 0000 TL1 0000 0000 DPH 0000 0000 3/B 4/C 5/D 6/E PLLDIV 0000 0000 KBLS 0000 0000 SSCS 1111 1000 TH0 0000 0000 KBE 0000 0000 SSDAT 1111 1111 TH1 0000 0000 WDTRST XXXX XXXX KBF 0000 0000 SSADR 1111 1110 AUXR XX0X 0000 CKCON0 0000 0000 PCON 00X1 0000 7/F CMOD 00XX X000 FCON (1) XXXX 0000 T2MOD XXXX XX00 CCAP0L XXXX XXXX UBYCTLX 0000 0000 CCAPM0 X000 0000 EECON XXXX XX00 RCAP2L 0000 0000 UEPIEN 0000 0000 UFNUML 0000 0000 IPL1 X0XX X000 RCAP2H 0000 0000 SPCON 0001 0100 UFNUMH 0000 0000 IPH1 X0XX X000 CCAP1L XXXX XXXX UBYCTHX 0000 0000 CCAPM1 X000 0000 CCAPM2 X000 0000 UEPCONX 1000 0000 TL2 0000 0000 SPSTA 0000 0000 USBCON 0000 0000 CCAPM3 X000 0000 UEPRST 0000 0000 TH2 0000 0000 SPDAT XXXX XXXX USBINT 0000 0000 UEPSTAX 0000 0000 USBADDR 1000 0000 USBIEN 0000 0000 IPH0 X000 0000 CKCON1 0000 0000 WDTPRG XXXX X000 UEPDATX 0000 0000 UEPNUM 0000 0000 CCAPM4 X000 0000 CCAP2L XXXX XXXX CCAP3L XXXX XXXX CCAP4L XXXX XXXX 2/A CCAP0H XXXX XXXX 3/B CCAP1H XXXX XXXX Non-Bit Addressable 4/C CCAP2H XXXX XXXX 5/D CCAP3H XXXX XXXX 6/E CCAP4H XXXX XXXX 7/F FFh SFR Descriptions F0h F7h E8h EFh E0h E7h D8h DFh D0h D7h C8h CFh C0h C7h B8h BFh B0h B7h A8h AFh A0h A7h 98h 9Fh 90h 97h 88h 8Fh 80h 87h Note: 1. FCON access is reserved for the Flash API and ISP software. Reserved 21 4337K–USB–04/08 The Special Function Registers (SFRs) of the AT89C5131 fall into the following categories: Table 6-2. C51 Core SFRs Add E0h F0h D0h Name Accumulator B Register Program Status Word Stack Pointer LSB of SPX Data Pointer Low byte LSB of DPTR Data Pointer High byte MSB of DPTR 7 6 5 4 3 2 1 0 Mnemonic ACC B PSW SP 81h DPL 82h DPH 83h Table 6-3. I/O Port SFRs Add 80h 90h A0h B0h C0h Name Port 0 Port 1 Port 2 Port 3 Port 4 (2bits) 7 6 5 4 3 2 1 0 Mnemonic P0 P1 P2 P3 P4 Table 6-4. Mnemonic TH0 TL0 TH1 TL1 TH2 TL2 TCON Timer SFR’s Add 8Ch 8Ah 8Dh 8Bh CDh CCh 88h Name Timer/Counter 0 High byte Timer/Counter 0 Low byte Timer/Counter 1 High byte Timer/Counter 1 Low byte Timer/Counter 2 High byte Timer/Counter 2 Low byte Timer/Counter 0 and 1 control Timer/Counter 0 and 1 Modes Timer/Counter 2 control Timer/Counter 2 Mode TF1 TR1 TF0 TR0 IE1 IT1 IE0 IT0 7 6 5 4 3 2 1 0 TMOD T2CON T2MOD 89h C8h C9h GATE1 TF2 C/T1# EXF2 M11 RCLK M01 TCLK GATE0 EXEN2 C/T0# TR2 M10 C/T2# T2OE M00 CP/RL2# DCEN 22 AT89C5130A/31A-M 4337K–USB–04/08 AT89C5130A/31A-M Table 6-4. Mnemonic RCAP2H Timer SFR’s (Continued) Add CBh Name Timer/Counter 2 Reload/Capture High byte Timer/Counter 2 Reload/Capture Low byte WatchDog Timer Reset WatchDog Timer Program S2 S1 S0 7 6 5 4 3 2 1 0 RCAP2L WDTRST WDTPRG CAh A6h A7h Table 6-5. Mnemonic SCON SBUF SADEN SADDR Serial I/O Port SFR’s Add 98h 99h B9h A9h Name Serial Control Serial Data Buffer Slave Address Mask Slave Address 7 FE/SM0 6 SM1 5 SM2 4 REN 3 TB8 2 RB8 1 TI 0 RI Table 6-6. Mnemonic BRL BDRCON Baud Rate Generator SFR’s Add 9Ah 9Bh Name Baud Rate Reload Baud Rate Control BRR TBCK RBCK SPD SRC 7 6 5 4 3 2 1 0 Table 6-7. Mnemonic Add CCON CMOD CL CH CCAPM 0 CCAPM 1 CCAPM 2 CCAPM 3 CCAPM 4 DAh DBh DCh DDh DEh D8h D9h E9h F9h PCA SFR’s Name PCA Timer/Counter Control PCA Timer/Counter Mode PCA Timer/Counter Low byte PCA Timer/Counter High byte 7 CF CIDL 6 CR WDTE 5 4 CCF4 3 CCF3 2 CCF2 CPS1 1 CCF1 CPS0 0 CCF0 ECF PCA Timer/Counter Mode 0 PCA Timer/Counter Mode 1 PCA Timer/Counter Mode 2 PCA Timer/Counter Mode 3 PCA Timer/Counter Mode 4 ECOM0 ECOM1 ECOM2 ECOM3 ECOM4 CAPP0 CAPP1 CAPP2 CAPP3 CAPP4 CAPN0 CAPN1 CAPN2 CAPN3 CAPN4 MAT0 MAT1 MAT2 MAT3 MAT4 TOG0 TOG1 TOG2 TOG3 TOG4 PWM0 PWM1 PWM2 PWM3 PWM4 ECCF0 ECCF1 ECCF2 ECCF3 ECCF4 23 4337K–USB–04/08 Table 6-7. Mnemonic Add CCAP0 H CCAP1 H CCAP2 H CCAP3 H CCAP4 H FAh FBh FCh FDh FEh PCA SFR’s Name PCA Compare Capture Module 0 H PCA Compare Capture Module 1 H PCA Compare Capture Module 2 H PCA Compare Capture Module 3 H PCA Compare Capture Module 4 H PCA Compare Capture Module 0 L CCAP0H7 CCAP0H6 CCAP0H5 CCAP0H4 CCAP0H3 CCAP0H2 CCAP0H1 CCAP0H0 CCAP1H7 CCAP1H6 CCAP1H5 CCAP1H4 CCAP1H3 CCAP1H2 CCAP1H1 CCAP1H0 CCAP2H7 CCAP2H6 CCAP2H5 CCAP2H4 CCAP2H3 CCAP2H2 CCAP2H1 CCAP2H0 CCAP3H7 CCAP3H6 CCAP3H5 CCAP3H4 CCAP3H3 CCAP3H2 CCAP3H1 CCAP3H0 CCAP4H7 CCAP4H6 CCAP4H5 CCAP4H4 CCAP4H3 CCAP4H2 CCAP4H1 CCAP4H0 7 6 5 4 3 2 1 0 CCAP0L EAh CCAP1L EBh CCAP2L ECh CCAP3L EDh CCAP4L EEh PCA Compare Capture Module 1 L PCA Compare Capture Module 2 L PCA Compare Capture Module 3 L PCA Compare Capture Module 4 L CCAP0L7 CCAP1L7 CCAP2L7 CCAP3L7 CCAP4L7 CCAP0L6 CCAP0L5 CCAP1L6 CCAP1L5 CCAP2L6 CCAP2L5 CCAP3L6 CCAP3L5 CCAP4L6 CCAP4L5 CCAP0L4 CCAP1L4 CCAP2L4 CCAP3L4 CCAP4L4 CCAP0L3 CCAP1L3 CCAP2L3 CCAP3L3 CCAP4L3 CCAP0L2 CCAP1L2 CCAP2L2 CCAP3L2 CCAP4L2 CCAP0L1 CCAP1L1 CCAP2L1 CCAP3L1 CCAP4L1 CCAP0L0 CCAP1L0 CCAP2L0 CCAP3L0 CCAP4L0 Table 6-8. Mnemonic Add IEN0 IEN1 IPL0 IPH0 IPL1 IPH1 A8h B1h B8h B7h B2h B3h Interrupt SFR’s Name Interrupt Enable Control 0 Interrupt Enable Control 1 Interrupt Priority Control Low 0 Interrupt Priority Control High 0 Interrupt Priority Control Low 1 Interrupt Priority Control High 1 7 EA 6 EC EUSB PPCL PPCH PUSBL PUSBH PT2L PT2H PSL PSH PT1L PT1H 5 ET2 4 ES 3 ET1 2 EX1 ESPI PX1L PX1H PSPIL PSPIH 1 ET0 ETWI PT0L PT0H PTWIL PTWIH 0 EX0 EKB PX0L PX0H PKBL PKBH Table 6-9. Mnemonic PLLCON PLLDIV PLL SFRs Add A3h A4h Name PLL Control PLL Divider R3 R2 R1 R0 N3 7 6 5 4 3 2 EXT48 N2 1 PLLEN N1 0 PLOCK N0 Table 6-10. Mnemonic KBF Keyboard SFRs Add 9Eh Name Keyboard Flag Register Keyboard Input Enable Register 7 KBF7 6 KBF6 5 KBF5 4 KBF4 3 KBF3 2 KBF2 1 KBF1 0 KBF0 KBE 9Dh KBE7 KBE6 KBE5 KBE4 KBE3 KBE2 KBE1 KBE0 24 AT89C5130A/31A-M 4337K–USB–04/08 AT89C5130A/31A-M Table 6-10. Mnemonic KBLS Keyboard SFRs Add 9Ch Name Keyboard Level Selector Register 7 KBLS7 6 KBLS6 5 KBLS5 4 KBLS4 3 KBLS3 2 KBLS2 1 KBLS1 0 KBLS0 Table 6-11. Mnemonic SSCON TWI SFRs Add 93h Name Synchronous Serial Control Synchronous Serial Control-Status Synchronous Serial Data Synchronous Serial Address 7 CR2 6 SSIE 5 STA 4 STO 3 SI 2 AA 1 CR1 0 CR0 SSCS 94h SC4 SC3 SC2 SC1 SC0 - - - SSDAT 95h SD7 SD6 SD5 SD4 SD3 SD2 SD1 SD0 SSADR 96h A7 A6 A5 A4 A3 A2 A1 A0 Table 6-12. Mnemonic SPCON SPI SFRs Add C3h Name Serial Peripheral Control Serial Peripheral Status-Control Serial Peripheral Data 7 SPR2 6 SPEN 5 SSDIS 4 MSTR 3 CPOL 2 CPHA 1 SPR1 0 SPR0 SPSTA SPDAT C4h C5h SPIF R7 WCOL R6 SSERR R5 MODF R4 R3 R2 R1 R0 Table 6-13. Mnemonic USBCON USBADDR USBINT USBIEN UEPNUM UEPCONX UEPSTAX UEPRST UEPINT UEPIEN USB SFR’s Add BCh C6h BDh BEh C7h D4h CEh D5h F8h C2h Name USB Global Control USB Address USB Global Interrupt USB Global Interrupt Enable USB Endpoint Number USB Endpoint X Control USB Endpoint X Status USB Endpoint Reset USB Endpoint Interrupt USB Endpoint Interrupt Enable USB Endpoint X FIFO Data 7 USBE FEN EPEN DIR 6 SUSPCLK UADD6 RXOUTB1 EP6RST EP6INT EP6INTE 5 SDRMWU P UADD5 WUPCPU EWUPCP U STALLRQ EP5RST EP5INT EP5INTE 4 DETACH UADD4 EORINT EEORINT TXRDY EP4RST EP4INT EP4INTE 3 UPRSM UADD3 SOFINT ESOFINT EPNUM3 DTGL STLCRC EP3RST EP3INT EP3INTE 2 RMWUPE UADD2 EPNUM2 EPDIR RXSETUP EP2RST EP2INT EP2INTE 1 CONFG UADD1 EPNUM1 EPTYPE1 RXOUTB0 EP1RST EP1INT EP1INTE 0 FADDEN UADD0 SPINT ESPINT EPNUM0 EPTYPE0 TXCMP EP0RST EP0INT EP0INTE UEPDATX CFh FDAT7 FDAT6 FDAT5 FDAT4 FDAT3 FDAT2 FDAT1 FDAT0 25 4337K–USB–04/08 Table 6-13. Mnemonic UBYCTLX USB SFR’s Add E2h Name USB Byte Counter Low (EP X) USB Byte Counter High (EP X) USB Frame Number Low USB Frame Number High 7 BYCT7 6 BYCT6 5 BYCT5 4 BYCT4 3 BYCT3 2 BYCT2 1 BYCT1 0 BYCT0 UBYCTHX E3h - - - - - BYCT10 BYCT9 BYCT8 UFNUML BAh FNUM7 FNUM6 FNUM5 FNUM4 FNUM3 FNUM2 FNUM1 FNUM0 UFNUMH BBh - - CRCOK CRCERR - FNUM10 FNUM9 FNUM8 Table 6-14. Mnemonic PCON AUXR AUXR1 CKCON0 CKCON1 LEDCON FCON EECON Other SFR’s Add 87h 8Eh A2h 8Fh AFh F1h D1h D2h Name Power Control Auxiliary Register 0 Auxiliary Register 1 Clock Control 0 Clock Control 1 LED Control Flash Control EEPROM Contol FPL3 EEPL3 7 SMOD1 DPU TWIX2 LED3 FPL2 EEPL2 FPL1 EEPL1 6 SMOD0 WDX2 5 M0 ENBOOT PCAX2 LED2 FPL0 EEPL0 FPS 4 POF SIX2 3 GF1 XRS1 GF3 T2X2 LED1 FMOD1 2 GF0 XRS2 T1X2 1 PD EXTRAM T0X2 LED0 FMOD0 EEE FBUSY EEBUSY 0 IDL A0 DPS X2 SPIX2 26 AT89C5130A/31A-M 4337K–USB–04/08 AT89C5130A/31A-M 7. Dual Data Pointer Register The additional data pointer can be used to speed up code execution and reduce code size. The dual DPTR structure is a way by which the chip will specify the address of an external data memory location. There are two 16-bit DPTR registers that address the external memory, and a single bit called DPS = AUXR1.0 (see Table 7-1) that allows the program code to switch between them (see Figure 7-1). Figure 7-1. Use of Dual Pointer External Data Memory 7 0 DPS DPTR1 DPTR0 AUXR1(A2H) DPH(83H) DPL(82H) Table 7-1. 7 Bit AUXR1 Register AUXR1- Auxiliary Register 1(0A2h) 6 Bit Mnemonic Description Reserved The value read from this bit is indeterminate. Do not set this bit. Reserved The value read from this bit is indeterminate. Do not set this bit. Enable Boot Flash Cleared to disable boot ROM. Set to map the boot ROM between F800h - 0FFFFh. 4 3 2 1 GF3 0 Reserved The value read from this bit is indeterminate. Do not set this bit. This bit is a general-purpose user flag. Always cleared. Reserved The value read from this bit is indeterminate. Do not set this bit. Data Pointer Selection Cleared to select DPTR0. Set to select DPTR1. 5 ENBOOT 4 3 GF3 2 0 1 0 DPS Number 7 6 - 5 ENBOOT 0 DPS Reset Value = XX[BLJB]X X0X0b Not bit addressable a. Bit 2 stuck at 0; this allows to use INC AUXR1 to toggle DPS without changing GF3. 27 4337K–USB–04/08 ASSEMBLY LANGUAGE ; Block move using dual data pointers ; Modifies DPTR0, DPTR1, A and PSW ; note: DPS exits opposite of entry state ; unless an extra INC AUXR1 is added ; 00A2 AUXR1 EQU 0A2H ; 0000 909000MOV DPTR,#SOURCE ; address of SOURCE 0003 05A2 INC AUXR1 ; switch data pointers 0005 90A000 MOV DPTR,#DEST ; address of DEST 0008 LOOP: 0008 05A2 INC AUXR1 ; switch data pointers 000A E0 MOVX A,@DPTR ; get a byte from SOURCE 000B A3 INC DPTR ; increment SOURCE address 000C 05A2 INC AUXR1 ; switch data pointers 000E F0 MOVX @DPTR,A ; write the byte to DEST 000F A3 INC DPTR ; increment DEST address 0010 70F6JNZ LOOP ; check for 0 terminator 0012 05A2 INC AUXR1 ; (optional) restore DPS INC is a short (2 bytes) and fast (12 clocks) way to manipulate the DPS bit in the AUXR1 SFR. However, note that the INC instruction does not directly force the DPS bit to a particular state, but simply toggles it. In simple routines, such as the block move example, only the fact that DPS is toggled in the proper sequence matters, not its actual value. In other words, the block move routine works the same whether DPS is '0' or '1' on entry. Observe that without the last instruction (INC AUXR1), the routine will exit with DPS in the opposite state. 28 AT89C5130A/31A-M 4337K–USB–04/08 AT89C5130A/31A-M 8. Program/Code Memory The AT89C5130A/31A-M implement 16/ 32 Kbytes of on-chip program/code memory. Figure 81 shows the split of internal and external program/code memory spaces depending on the product. The Flash memory increases EPROM and ROM functionality by in-circuit electrical erasure and programming. Thanks to the internal charge pump, the high voltage needed for programming or erasing Flash cells is generated on-chip using the standard VDD voltage. Thus, the Flash Memory can be programmed using only one voltage and allows In- application Software Programming commonly known as IAP. Hardware programming mode is also available using specific programming tool. Figure 8-1. Program/Code Memory Organization FFFFh FFFFh 48 Kbytes External Code 32 Kbytes External Code 4000h 3FFFh 8000h 7FFFh 16 Kbytes Flash 32 Kbytes Flash 0000h 0000h AT89C5130A AT89C5131A Note: If the program executes exclusively from on-chip code memory (not from external memory), beware of executing code from the upper byte of on-chip memory (3FFFh/7FFFh) and thereby disrupting I/O Ports 0 and 2 due to external prefetch. Fetching code constant from this location does not affect Ports 0 and 2. 8.1 8.1.1 External Code Memory Access Memory Interface The external memory interface comprises the external bus (Port 0 and Port 2) as well as the bus control signals (PSEN, and ALE). Figure 8-2 shows the structure of the external address bus. P0 carries address A7:0 while P2 carries address A15:8. Data D7:0 is multiplexed with A7:0 on P0. Table 8-1 describes the external memory interface signals. 29 4337K–USB–04/08 Figure 8-2. External Code Memory Interface Structure AT89C5130A AT89C5131 P2 ALE P0 AD7:0 Latch A7:0 A7:0 D7:0 PSEN OE Flash EPROM A15:8 A15:8 Table 8-1. External Data Memory Interface Signals Type O Description Address Lines Upper address lines for the external bus. Address/Data Lines Multiplexed lower address lines and data for the external memory. Address Latch Enable ALE signals indicates that valid address information are available on lines AD7:0. Program Store Enable Output This signal is active low during external code fetch or external code read (MOVC instruction). Alternate Function P2.7:0 Signal Name A15:8 AD7:0 I/O P0.7:0 ALE O - PSEN O - 8.1.2 External Bus Cycles This section describes the bus cycles the AT89C5130A/31A-M executes to fetch code (see Figure 8-3) in the external program/code memory. External memory cycle takes 6 CPU clock periods. This is equivalent to 12 oscillator clock periods in standard mode or 6 oscillator clock periods in X2 mode. For further information on X2 mode (see the clock Section). For simplicity, the accompanying figure depicts the bus cycle waveforms in idealized form and do not provide precise timing information. Figure 8-3. External Code Fetch Waveforms CPU Clock ALE PSEN P0 D7:0 P2 PCH PCL D7:0 PCL D7:0 PCH PCH 30 AT89C5130A/31A-M 4337K–USB–04/08 AT89C5130A/31A-M 8.2 Flash Memory Architecture AT89C5130A/31A-M features two on-chip Flash memories: • Flash memory FM0: containing 32 Kbytes of program memory (user space) organized into 128-byte pages, • Flash memory FM1: 3 Kbytes for bootloader and Application Programming Interfaces (API). The FM0 supports both parallel programming and Serial In-System Programming (ISP) whereas FM1 supports only parallel programming by programmers. The ISP mode is detailed in the “InSystem Programming” section. All Read/Write access operations on Flash memory by user application are managed by a set of API described in the “In-System Programming” section. Figure 8-4. Flash Memory Architecture 3 Kbytes Flash Memory Boot Space FM1 FFFFh Hardware Security (1 Byte) Extra Row (128 Bytes) Column Latches (128 Bytes) 3FFFh for AT89C5130A for 16 KB 7FFFh for AT89C5131A for 32 KB 16/32 KB Flash Memory User Space FM0 F400h FM1 mapped between FFFFh and F400h when bit ENBOOT is set in AUXR1 register 0000h 8.2.1 FM0 Memory Architecture The Flash memory is made up of 4 blocks (see Figure 8-4): 1. The memory array (user space) 32 Kbytes 2. The Extra Row 3. The Hardware security bits 4. The column latch registers 8.2.1.1 User Space This space is composed of a 16/32 Kbytes Flash memory organized in 128/256 pages of 128 bytes. It contains the user’s application code. 8.2.1.2 Extra Row (XRow) This row is a part of FM0 and has a size of 128 bytes. The extra row contains information for bootloader usage (see 9-3 “Software Registers” on page 41) Hardware Security Space The hardware security space is a part of FM0 and has a size of 1 byte. The 4 MSB can be read/written by software. The 4 LSB can only be read by software and written by hardware in parallel mode. 8.2.1.3 31 4337K–USB–04/08 8.2.1.4 Column Latches The column latches, also part of FM0, have a size of full page (128 bytes). The column latches are the entrance buffers of the three previous memory locations (user array, XRow and Hardware security byte). 8.3 Overview of FM0 Operations The CPU interfaces to the Flash memory through the FCON register and AUXR1 register. These registers are used to: • Map the memory spaces in the adressable space • Launch the programming of the memory spaces • Get the status of the Flash memory (busy/not busy) • Select the Flash memory FM0/FM1. 8.3.1 Mapping of the Memory Space By default, the user space is accessed by MOVC instruction for read only. The column latches space is made accessible by setting the FPS bit in FCON register. Writing is possible from 0000h to 3FFFH/7FFFh, address bits 6 to 0 are used to select an address within a page while bits 14 to 7 are used to select the programming address of the page. Setting this bit takes precedence on the EXTRAM bit in AUXR register. The other memory spaces (user, extra row, hardware security) are made accessible in the code segment by programming bits FMOD0 and FMOD1 in FCON register in accordance with Table 8-2. A MOVC instruction is then used for reading these spaces. Table 8-2. FM0 Blocks Select Bits FMOD1 0 0 1 1 FMOD0 0 1 0 1 FM0 Adressable Space User (0000h-FFFFh) Extra Row(FF80h-FFFFh) Hardware Security (0000h) reserved 8.3.2 Launching Programming FPL3:0 bits in FCON register are used to secure the launch of programming. A specific sequence must be written in these bits to unlock the write protection and to launch the programming. This sequence is 5 followed by A. Table 8-3 summarizes the memory spaces to program according to FMOD1:0 bits. 32 AT89C5130A/31A-M 4337K–USB–04/08 AT89C5130A/31A-M Table 8-3. Programming Spaces Write to FCON FPL3:0 5 User A 5 Extra Row A Security Space 5 A 5 Reserved A X 1 1 No action X X X X 0 1 1 1 1 0 0 1 X X 0 0 0 1 FPS X FMOD1 0 FMOD0 0 Operation No action Write the column latches in user space No action Write the column latches in extra row space No action Write the fuse bits space No action The Flash memory enters a busy state as soon as programming is launched. In this state, the memory is not available for fetching code. Thus to avoid any erratic execution during programming, the CPU enters Idle mode. Exit is automatically performed at the end of programming. Note: Interrupts that may occur during programming time must be disabled to avoid any spurious exit of the idle mode. 8.3.3 Status of the Flash Memory The bit FBUSY in FCON register is used to indicate the status of programming. FBUSY is set when programming is in progress. 8.3.4 Selecting FM0/FM1 The bit ENBOOT in AUXR1 register is used to choose between FM0 and FM1 mapped up to F800h. Loading the Column Latches Any number of data from 1 byte to 128 bytes can be loaded in the column latches. This provides the capability to program the whole memory by byte, by page or by any number of bytes in a page. When programming is launched, an automatic erase of the locations loaded in the column latches is first performed, then programming is effectively done. Thus, no page or block erase is needed and only the loaded data are programmed in the corresponding page. The following procedure is used to load the column latches and is summarized in Figure 8-5: • Map the column latch space by setting FPS bit. • Load the DPTR with the address to load. • Load Accumulator register with the data to load. • Execute the MOVX @DPTR, A instruction. • If needed loop the three last instructions until the page is completely loaded. 8.3.5 33 4337K–USB–04/08 Figure 8-5. Column Latches Loading Procedure Column Latches Loading Column Latches Mapping FPS = 1 Data Load DPTR = Address ACC = Data Exec: MOVX @DPTR, A Last Byte to load? Data memory Mapping FPS = 0 8.3.6 8.3.6.1 Programming the Flash Spaces User The following procedure is used to program the User space and is summarized in Figure 8-6: • Load data in the column latches from address 0000h to 7FFFh(1). • Disable the interrupts. • Launch the programming by writing the data sequence 50h followed by A0h in FCON register. The end of the programming indicated by the FBUSY flag cleared. • Enable the interrupts. Note: 1. The last page address used when loading the column latch is the one used to select the page programming address. 8.3.6.2 Extra Row The following procedure is used to program the Extra Row space and is summarized in Figure 86: • Load data in the column latches from address FF80h to FFFFh. • Disable the interrupts. • Launch the programming by writing the data sequence 52h followed by A2h in FCON register. The end of the programming indicated by the FBUSY flag cleared. • Enable the interrupts. 34 AT89C5130A/31A-M 4337K–USB–04/08 AT89C5130A/31A-M Figure 8-6. Flash and Extra Row Programming Procedure Flash Spaces Programming Column Latches Loading see Figure 8-5 Disable IT EA = 0 Launch Programming FCON = 5xh FCON = Axh FBusy Cleared? Erase Mode FCON = 00h End Programming Enable IT EA = 1 8.3.6.3 Hardware Security The following procedure is used to program the Hardware Security space and is summarized in Figure 8-7: • Set FPS and map Hardware byte (FCON = 0x0C) • Disable the interrupts. • Load DPTR at address 0000h. • Load Accumulator register with the data to load. • Execute the MOVX @DPTR, A instruction. • Launch the programming by writing the data sequence 54h followed by A4h in FCON register. The end of the programming indicated by the FBusy flag cleared. • Enable the interrupts. 35 4337K–USB–04/08 Figure 8-7. Hardware Programming Procedure Flash Spaces Programming FCON = 0Ch Data Load DPTR = 00h ACC = Data Exec: MOVX @DPTR, A Disable IT EA = 0 Launch Programming FCON = 54h FCON = A4h FBusy Cleared? Erase Mode FCON = 00h End Programming Enable IT EA = 1 8.3.7 8.3.7.1 Reading the Flash Spaces User The following procedure is used to read the User space and is summarized in Figure 8-8: • Map the User space by writing 00h in FCON register. • Read one byte in Accumulator by executing MOVC A, @A+DPTR with A = 0 & DPTR = 0000h to FFFFh. 8.3.7.2 Extra Row The following procedure is used to read the Extra Row space and is summarized in Figure 8-8: • Map the Extra Row space by writing 02h in FCON register. • Read one byte in Accumulator by executing MOVC A, @A+DPTR with A = 0 & DPTR = FF80h to FFFFh. 36 AT89C5130A/31A-M 4337K–USB–04/08 AT89C5130A/31A-M 8.3.7.3 Hardware Security The following procedure is used to read the Hardware Security space and is summarized in Figure 8-8: • Map the Hardware Security space by writing 04h in FCON register. • Read the byte in Accumulator by executing MOVC A, @A+DPTR with A = 0 & DPTR = 0000h. Figure 8-8. Reading Procedure Flash Spaces Reading Flash Spaces Mapping FCON = 00000xx0b Data Read DPTR = Address ACC = 0 Exec: MOVC A, @A+DPTR Erase Mode FCON = 00h 8.4 Registers Table 8-4. FCON (S:D1h) Flash Control Register 7 FPL3 6 FPL2 5 FPL1 4 FPL0 3 FPS 2 FMOD1 1 FMOD0 0 FBUSY Bit Bit Number Mnemonic Description Programming Launch Command Bits Write 5Xh followed by AXh to launch the programming according to FMOD1:0. (see Table 8-3.) Flash Map Program Space Set to map the column latch space in the data memory space. Clear to re-map the data memory space. Flash Mode See Table 8-2 or Table 8-3. Flash Busy Set by hardware when programming is in progress. Clear by hardware when programming is done. Can not be cleared by software. 7-4 FPL3:0 3 FPS 2-1 FMOD1:0 0 FBUSY Reset Value = 0000 0000b 37 4337K–USB–04/08 9. Flash EEPROM Memory 9.1 General Description The Flash memory increases EPROM functionality with in-circuit electrical erasure and programming. It contains 16/32 Kbytes of program memory organized in 128/256 pages of 128 bytes, respectively. This memory is both parallel and serial In-System Programmable (ISP). ISP allows devices to alter their own program memory in the actual end product under software control. A default serial loader (bootloader) program allows ISP of the Flash. The programming does not require 12V external programming voltage. The necessary high programming voltage is generated on-chip using the standard VCC pins of the microcontroller. 9.2 Features • Flash EEPROM internal program memory. • Boot vector allows user-provided Flash loader code to reside anywhere in the Flash memory space. This configuration provides flexibility to the user. • Default loader in Boot EEPROM allows programming via the serial port without the need of a user provided loader. • Up to 64K bytes external program memory if the internal program memory is disabled (EA = 0). • Programming and erase voltage with standard power supply. • Read/Program/Erase: • Byte-wise read (without wait state). • Byte or page erase and programming (10 ms). • Typical programming time (32 Kbytes) in 4.5 sec. • Parallel programming with 87C51 compatible hardware interface to programmer. • Programmable security for the code in the Flash. • 100K write cycles for code memory • 1K write cycles for configuration bits (BLJB, X2, OSCON1, OSCON0) • 10 years data retention 9.3 Flash Programming and Erasure The 16/32 Kbytes Flash is programmed by bytes or by pages of 128 bytes. It is not necessary to erase a byte or a page before programming. The programming of a byte or a page includes a self erase before programming. There are three methods of programming the Flash memory: 1. The on-chip ISP bootloader may be invoked which will use low level routines to program the pages. The interface used for serial downloading of Flash is the USB. 2. The Flash may be programmed or erased in the end-user application by calling lowlevel routines through a common entry point in the Boot Flash. 3. The Flash may be programmed using the parallel method. The bootloader and the Application Programming Interface (API) routines are located in the Flash Bootloader. 38 AT89C5130A/31A-M 4337K–USB–04/08 AT89C5130A/31A-M 9.4 Flash Registers and Memory Map The AT89C5130A/31A-M Flash memory uses several registers: • Hardware register can be accessed with a parallel programmer.Some bits of the hardware register can be changed, also, by API (i.e. X2 and BLJB bits of Hardware security Byte) or ISP. • Software registers are in a special page of the Flash memory which can be accessed through the API or with the parallel programming modes. This page, called “Extra Flash Memory”, is not in the internal Flash program memory addressing space. 9.4.1 Hardware Registers The only hardware register of the AT89C5130A/31A-M is called Hardware Security Byte (HSB). Table 9-1. 7 X2 Bit Number Hardware Security Byte (HSB) 6 BLJB Bit Mnemonic Description X2 Mode Cleared to force X2 mode (6 clocks per instruction) Set to force X1 mode, Standard Mode (Default). Bootloader Jump Bit 5 OSCON1 4 OSCON0 3 2 LB2 1 LB1 0 LB0 7 X2 6 BLJB Set this bit to start the user’s application on next reset at address 0000h. Cleared this bit to start the bootloader at address F400h (default). Oscillator Control Bits These two bits are used to control the oscillator in order to reduce consumption. 5-4 OSCON1 OSCON0 Description OSCON1-0 1 1 The oscillator is configured to run from 0 to 32 MHz 1 0 The oscillator is configured to run from 0 to 16 MHz 0 1 The oscillator is configured to run from 0 to 8 MHz 0 0 This configuration shouldn’t be set LB2-0 Reserved User Memory Lock Bits See Table 9-2 3 2-0 9.4.1.1 Bootloader Jump Bit (BLJB) One bit of the HSB, the BLJB bit, is used to force the boot address: • When this bit is set the boot address is 0000h. • When this bit is reset the boot address is F400h. By default, this bit is cleared and the ISP is enabled. 9.4.1.2 Flash Memory Lock Bits The three lock bits provide different levels of protection for the on-chip code and data, when programmed as shown in Table 9-2. 39 4337K–USB–04/08 Table 9-2. Program Lock bits Program Lock Bits Security level 1 LB0 U LB1 U LB2 U Protection Description No program lock features enabled. MOVC instruction executed from external program memory is disabled from fetching code bytes from any internal memory, EA is sampled and latched on reset, and further parallel programming of the Flash and of the EEPROM (boot and Xdata) is disabled. ISP and software programming with API are still allowed. Same as 2, also verify through parallel programming interface is disabled and serial programming ISP is still allowed. Same as 3, also external execution is disabled. 2 P U U 3 X P U 4 X X P Notes: 1. U: unprogrammed or “one” level. 2. P: programmed or “zero” level. 3. X: don’t care 4. WARNING: Security level 2 and 3 should only be programmed after verification. These security bits protect the code access through the parallel programming interface. They are set by default to level 4. The code access through the ISP is still possible and is controlled by the “software security bits” which are stored in the extra Flash memory accessed by the ISP firmware. To load a new application with the parallel programmer, a chip erase must be done first. This will set the HSB in its inactive state and will erase the Flash memory. The part reference can always be read using Flash parallel programming modes. 9.4.1.3 Default Values The default value of the HSB provides parts ready to be programmed with ISP: • BLJB: Cleared to force ISP operation. • X2: Set to force X1 mode (Standard Mode) • OSCON1-0: Set to start with 32 MHz oscillator configuration value. • LB2-0: Security level four to protect the code from a parallel access with maximum security. 9.4.2 Software Registers Several registers are used, in factory and by parallel programmers, to make copies of hardware registers contents. These values are used by Atmel ISP (see Section “In-System Programming (ISP)”). These registers are in the “Extra Flash Memory” part of the Flash memory. This block is also called ”XAF” or eXtra Array Flash. They are accessed in the following ways: • Commands issued by the parallel memory programmer. • Commands issued by the ISP software. • Calls of API issued by the application software. Several software registers are described in Table 9-3. 40 AT89C5130A/31A-M 4337K–USB–04/08 AT89C5130A/31A-M Table 9-3. Software Registers Address 01 00 05 30 Mnemonic SBV BSB SSB – Description Software Boot Vector Boot Status Byte Software Security Byte Copy of the Manufacturer Code Copy of the Device ID #1: Family Code Copy of the Device ID #2: Memories Copy of the Device ID #3: Name Default value FFh 0FFh FFh 58h – – – Atmel C51 X2, Electrically Erasable AT89C5130A/31A-M 32 Kbyte AT89C5130A/31A-M 32 Kbyte, revision 0 31 – D7h 60 – F7h 61 – DFh After programming the part by ISP, the BSB must be cleared (00h) in order to allow the application to boot at 0000h. The content of the Software Security Byte (SSB) is described in Table 9-4 and Table 9-5. To assure code protection from a parallel access, the HSB must also be at the required level. Table 9-4. 7 Bit Number 7 Software Security Byte (SSB) 6 Bit Mnemonic Description Reserved Do not clear this bit. Reserved Do not clear this bit. Reserved Do not clear this bit. Reserved Do not clear this bit. Reserved Do not clear this bit. Reserved Do not clear this bit. User Memory Lock Bits See Table 9-5 5 4 3 2 1 LB1 0 LB0 6 - 5 - 4 - 3 - 2 - 1-0 LB1-0 The two lock bits provide different levels of protection for the on-chip code and data, when programmed as shown to Table 9-5. 41 4337K–USB–04/08 Table 9-5. Program Lock Bits of the SSB Program Lock Bits Security Level 1 2 3 LB0 U P P LB1 U U P Protection Description No program lock features enabled. ISP programming of the Flash is disabled. Same as 2, also verify through ISP programming interface is disabled. Notes: 1. U: unprogrammed or "one" level. 2. P: programmed or “zero” level. 3. WARNING: Security level 2 and 3 should only be programmed after Flash and code verification. 9.5 Flash Memory Status AT89C5130A/31A-M parts are delivered with the ISP boot in the Flash memory. After ISP or parallel programming, the possible contents of the Flash memory are summarized in Figure 9-1: Figure 9-1. Flash Memory Possible Contents 3FFFh AT89C5130A-M 7FFFh AT89C5131A-M Virgin Application Virgin or Application Dedicated ISP Application Virgin or Application Virgin or Application Dedicated ISP After parallel programming After parallel programming After parallel programming 0000h Default After ISP After ISP 9.6 Memory Organization In the AT89C5130A/31A-M, the lowest 16/32K of the 64 Kbyte program memory address space is filled by internal Flash. When the EA is pin high, the processor fetches instructions from internal program Flash. Bus expansion for accessing program memory from 16/32K upward is automatic since external instruction fetches occur automatically when the program counter exceeds 3FFFh (16K) or 7FFFh (32K). If the EA pin is tied low, all program memory fetches are from external memory. If all storage is on chip, then byte location 3FFFh (16K) or 7FFFh (32K) should be left vacant to prevent and undesired pre-fetch from external program memory address 4000h (16K) or 8000h (32K). 42 AT89C5130A/31A-M 4337K–USB–04/08 AT89C5130A/31A-M 10. EEPROM Data Memory 10.1 Description The 1-Kbyte on-chip EEPROM memory block is located at addresses 0000h to 03FFh of the ERAM memory space and is selected by setting control bits in the EECON register. A read in the EEPROM memory is done with a MOVX instruction. A physical write in the EEPROM memory is done in two steps: write data in the column latches and transfer of all data latches into an EEPROM memory row (programming). The number of data written on the page may vary from 1 to 128 bytes (the page size). When programming, only the data written in the column latch is programmed and a ninth bit is used to obtain this feature. This provides the capability to program the whole memory by bytes, by page or by a number of bytes in a page. Indeed, each ninth bit is set when the writing the corresponding byte in a row and all these ninth bits are reset after the writing of the complete EEPROM row. 10.2 Write Data in the Column Latches Data is written by byte to the column latches as for an external RAM memory. Out of the 11 address bits of the data pointer, the 4 MSBs are used for page selection (row) and 7 are used for byte selection. Between two EEPROM programming sessions, all the addresses in the column latches must stay on the same page, meaning that the 4 MSB must not be changed. The following procedure is used to write to the column latches: • Set bit EEE of EECON register • Load DPTR with the address to write • Store A register with the data to be written • Execute a MOVX @DPTR, A • If needed, loop the three last instructions until the end of a 128 bytes page 10.3 Programming The EEPROM programming consists on the following actions: • Writing one or more bytes of one page in the column latches. Normally, all bytes must belong to the same page; if not, the first page address will be latched and the others discarded. • Launching programming by writing the control sequence (52h followed by A2h) to the EECON register. • EEBUSY flag in EECON is then set by hardware to indicate that programming is in progress and that the EEPROM segment is not available for reading. • The end of programming is indicated by a hardware clear of the EEBUSY flag. 10.4 Read Data The following procedure is used to read the data stored in the EEPROM memory: • Set bit EEE of EECON register • Stretch the MOVX to accommodate the slow access time of the column latch (Set bit M0 of AUXR register) • Load DPTR with the address to read • Execute a MOVX A, @DPTR 43 4337K–USB–04/08 10.5 Registers Table 10-1. 7 EEPL3 EECON (S:0D2h) EECON Register 6 EEPL2 Bit Mnemonic EEPL3-0 5 EEPL1 4 EEPL0 3 2 1 EEE 0 EEBUSY Bit Number 7-4 Description Programming Launch command bits Write 5Xh followed by AXh to EEPL to launch the programming. Reserved The value read from this bit is indeterminate. Do not set this bit. Reserved The value read from this bit is indeterminate. Do not set this bit. Enable EEPROM Space bit Set to map the EEPROM space during MOVX instructions (Write in the column latches) Clear to map the ERAM space during MOVX. Programming Busy flag Set by hardware when programming is in progress. Cleared by hardware when programming is done. Cannot be set or cleared by software. 3 - 2 - 1 EEE 0 EEBUSY Reset Value = XXXX XX00b Not bit addressable 44 AT89C5130A/31A-M 4337K–USB–04/08 AT89C5130A/31A-M 11. In-System Programming (ISP) With the implementation of the User Space (FM0) and the Boot Space (FM1) in Flash technology the AT89C5130A/31A-M allows the system engineer the development of applications with a very high level of flexibility. This flexibility is based on the possibility to alter the customer program at any stages of a product’s life: • Before mounting the chip on the PCB, FM0 flash can be programmed with the application code. FM1 is always preprogrammed by Atmel with a USB bootloader.(1) • Once the chip is mounted on the PCB, it can be programmed by serial mode via the USB bus. Note: 1. The user can also program his own bootloader in FM1. This ISP allows code modification over the total lifetime of the product. Besides the default Bootloaders Atmel provide customers all the needed Application-Programming-Interfaces (API) which are needed for the ISP. The API are located in the Boot memory. This allow the customer to have a full use of the 32-Kbyte user memory. 11.1 Flash Programming and Erasure There are three methods for programming the Flash memory: • The Atmel bootloader located in FM1 is activated by the application. Low level API routines (located in FM1)will be used to program FM0. The interface used for serial downloading to FM0 is the USB. API can be called also by user’s bootloader located in FM0 at [SBV]00h. • A further method exist in activating the Atmel boot loader by hardware activation. See the Section “Hardware Registers”. • The FM0 can be programmed also by the parallel mode using a programmer. 45 4337K–USB–04/08 Figure 11-1. Flash Memory Mapping FFFFh 3K Bytes IAP Bootloader FM1 F400h 3FFFh Custom Bootloader [SBV]00h 16K Bytes 7FFFh Custom Bootloader [SBV]00h 32K Bytes FM1 Mapped between F400h and FFFFh when API Called Flash Memory FM0 Flash Memory FM0 0000h C5130A 0000h C5131A 11.2 11.2.1 Boot Process Software Boot Process Example Many algorithms can be used for the software boot process. Below are descriptions of the different flags and Bytes. Boot Loader Jump bit (BLJB): - This bit indicates if on RESET the user wants to jump to this application at address @0000h on FM0 or execute the boot loader at address @F400h on FM1. - BLJB = 0 (i.e. bootloader FM1 executed after a reset) is the default Atmel factory programming. -To read or modify this bit, the APIs are used. Boot Vector Address (SBV): - This byte contains the MSB of the user boot loader address in FM0. - The default value of SBV is FFh (no user boot loader in FM0). - To read or modify this byte, the APIs are used. Extra Byte (EB) & Boot Status Byte (BSB): - These Bytes are reserved for customer use. - To read or modify these Bytes, the APIs are used. 46 AT89C5130A/31A-M 4337K–USB–04/08 AT89C5130A/31A-M Figure 11-2. Hardware Boot Process Algorithm RESET bit ENBOOT in AUXR1 Register Is Initialized with BLJB Inverted. Example, if BLJB=0, ENBOOT Hardware ENBOOT = 0 PC = 0000h BLJB == 0 ? is set (=1) during reset, thus the bootloader is executed after the reset. ENBOOT = 1 PC = F400h Software Application in FM0 Bootloader in FM1 11.3 Application-Programming-Interface Several Application Program Interface (API) calls are available for use by an application program to permit selective erasing and programming of Flash pages. All calls are made by functions. All these APIs are described in detail in the following document on the Atmel web site. – Datasheet Bootloader USB AT89C5131. 11.4 XROW Bytes The EXTRA ROW (XROW) includes 128 bytes. Some of these bytes are used for specific purpose in conjonction with the bootloader. Table 11-1. XROW Mapping Default Value 58h D7h BBh Address 30h 31h 60h Description Copy of the Manufacturer Code Copy of the Device ID#1: Family code Copy of the Device ID#2: Memories size and type 47 4337K–USB–04/08 Description Copy of the Device ID#3: Name and Revision Default Value FFh Address 61h 11.5 Hardware Conditions It is possible to force the controller to execute the bootloader after a Reset with hardware conditions. Depending on the product type (low pin count or high pin count package), there are two methods to apply the hardware conditions. 11.5.1 High Pin Count Hardware Conditions (PLCC52, QFP64) For high pin count packages, the hardware conditons (EA = 1, PSEN = 0) are sampled during the RESET rising edge to force the on-chip bootloader execution (See Figure 27-5 on page 172). In this way the bootloader can be carried out regardless of the user Flash memory content. It is recommended to pull the PSEN pin down to ground though a 1K resistor to prevent the PSEN pin from being damaged (see Figure 11-3 below). Figure 11-3. ISP Hardware conditions VCC VCC VCC EA ALE Unconnected C2 RST XTAL2 GND Crystal GND C1 Bootloader /PSEN XTAL1 1K GND GND VSS GND As PSEN is an output port in normal operating mode (running user application or bootloader code) after reset, it is recommended to release PSEN after rising edge of reset signal. To ensure correct microcontroller startup, the PSEN pin should not be tied to ground during power-on (see Figure 11-4 below). 48 AT89C5130A/31A-M 4337K–USB–04/08 AT89C5130A/31A-M Figure 11-4. Hardware conditions typical sequence during power-on. VCC PSEN RST 11.5.2 Low Pin Count Hardware Conditions (QFN32) Low pin count products do not have PSEN signal, thus for these products, the bootloader is always executed after reset thanks to the BLJB bit. The Hardware Condition are detected at the begining of the bootloader execution from reset. The default factory Hardware Condition is assigned to port P1. • P1 must be equal to FEh In order to offer the best flexibility, the user can define its own Hardware Condition on one of the following Ports: • Port1 • Port3 • Port4 (only bit0 and bit1) The Hardware Condition configuration are stored in three bytes called P1_CF, P3_CF, P4_CF. These bytes can be modified by the user through a set of API or through an ISP command. Note: 1. The BLJB must be at 0 (programmed) to be able to restart the bootloader. 2. BLJB can always be changed by the means of API, whether it's a low or high pin count package.But for a low pin count version, if BLJB=1, no ISP via the Bootloader is further possible (because the HW conditions are never evaluated, as described in the USB Bootloader Datasheet). To go back to ISP, BLJB needs to be changed by a parallel programmer(or by the APIs). See a detailed description in the applicable Document. – Datasheet Bootloader USB AT89C5131. 49 4337K–USB–04/08 12. On-chip Expanded RAM (ERAM) The AT89C5130A/31A-M provides additional Bytes of random access memory (RAM) space for increased data parameters handling and high level language usage. AT89C5130A/31A-M devices have expanded RAM in external data space; maximum size and location are described in Table 12-1. Table 12-1. Description of Expanded RAM Address Part Number AT89C5130A/31A-M ERAM Size 1024 Start 00h End 3FFh The AT89C5130A/31A-M has on-chip data memory which is mapped into the following four separate segments. 1. The Lower 128 bytes of RAM (addresses 00h to 7Fh) are directly and indirectly addressable. 2. The Upper 128 bytes of RAM (addresses 80h to FFh) are indirectly addressable only. 3. The Special Function Registers, SFRs, (addresses 80h to FFh) are directly addressable only. 4. The expanded RAM bytes are indirectly accessed by MOVX instructions, and with the EXTRAM bit cleared in the AUXR register (see Table 12-1) The lower 128 bytes can be accessed by either direct or indirect addressing. The Upper 128 bytes can be accessed by indirect addressing only. The Upper 128 bytes occupy the same address space as the SFR. That means they have the same address, but are physically separate from SFR space. Figure 12-1. Internal and External Data Memory Address 0FFh or 3FFh(*) 0FFh Upper 128 bytes Internal RAM indirect accesses ERAM 80h 7Fh Lower 128 bytes Internal RAM direct or indirect accesses 00 00 80h 0FFh 0FFFFh Special Function Register direct accesses External Data Memory 00FFh up to 03FFh (*) 0000 (*) Depends on XRS1..0 When an instruction accesses an internal location above address 7Fh, the CPU knows whether the access is to the upper 128 bytes of data RAM or to SFR space by the addressing mode used in the instruction. 50 AT89C5130A/31A-M 4337K–USB–04/08 AT89C5130A/31A-M • Instructions that use direct addressing access SFR space. For example: MOV 0A0H, # data, accesses the SFR at location 0A0h (which is P2). • Instructions that use indirect addressing access the Upper 128 bytes of data RAM. For example: MOV atR0, # data where R0 contains 0A0h, accesses the data byte at address 0A0h, rather than P2 (whose address is 0A0h). • The ERAM bytes can be accessed by indirect addressing, with EXTRAM bit cleared and MOVX instructions. This part of memory which is physically located on-chip, logically occupies the first bytes of external data memory. The bits XRS0 and XRS1 are used to hide a part of the available ERAM as explained in Table 12-1. This can be useful if external peripherals are mapped at addresses already used by the internal ERAM. • With EXTRAM = 0, the ERAM is indirectly addressed, using the MOVX instruction in combination with any of the registers R0, R1 of the selected bank or DPTR. An access to ERAM will not affect ports P0, P2, P3.6 (WR) and P3.7 (RD). For example, with EXTRAM = 0, MOVX atR0, # data where R0 contains 0A0H, accesses the ERAM at address 0A0H rather than external memory. An access to external data memory locations higher than the accessible size of the ERAM will be performed with the MOVX DPTR instructions in the same way as in the standard 80C51, with P0 and P2 as data/address busses, and P3.6 and P3.7 as write and read timing signals. Accesses to ERAM above 0FFH can only be done by the use of DPTR. • With EXTRAM = 1, MOVX @Ri and MOVX @DPTR will be similar to the standard 80C51. MOVX at Ri will provide an eight-bit address multiplexed with data on Port0 and any output port pins can be used to output higher order address bits. This is to provide the external paging capability. MOVX @DPTR will generate a sixteen-bit address. Port2 outputs the highorder eight address bits (the contents of DPH) while Port0 multiplexes the low-order eight address bits (DPL) with data. MOVX at Ri and MOVX @DPTR will generate either read or write signals on P3.6 (WR) and P3.7 (RD). The stack pointer (SP) may be located anywhere in the 256 bytes RAM (lower and upper RAM) internal data memory. The stack may not be located in the ERAM. The M0 bit allows to stretch the ERAM timings; if M0 is set, the read and write pulses are extended from 6 to 30 clock periods. This is useful to access external slow peripherals. Table 12-2. 7 DPU Bit Number AUXR Register AUXR - Auxiliary Register (8Eh) 6 Bit Mnemonic Description Disable Weak Pull Up 5 M0 4 3 XRS1 2 XRS0 1 EXTRAM 0 AO 7 DPU Cleared to enabled weak pull up on standard Ports. Set to disable weak pull up on standard Ports. Reserved The value read from this bit is indeterminate. Do not set this bit 6 - 51 4337K–USB–04/08 Bit Number Bit Mnemonic Description Pulse length 5 M0 Cleared to stretch MOVX control: the RD and the WR pulse length is 6 clock periods (default). Set to stretch MOVX control: the RD and the WR pulse length is 30 clock periods. 4 3 XRS1 Reserved The value read from this bit is indeterminate. Do not set this bit ERAM Size XRS1XRS0 0 0 ERAM size 256 bytes 512 bytes 768 bytes 1024 bytes (default) 2 XRS0 0 1 1 1 0 1 1 EXTRAM EXTRAM bit Cleared to access internal ERAM using MOVX at Ri at DPTR. Set to access external memory. ALE Output bit Cleared, ALE is emitted at a constant rate of 1/6 the oscillator frequency (or 1/3 if X2 mode is used) (default). Set, ALE is active only when a MOVX or MOVC instruction is used. 0 AO Reset Value = 0X0X 1100b Not bit addressable 52 AT89C5130A/31A-M 4337K–USB–04/08 AT89C5130A/31A-M 13. Timer 2 The Timer 2 in the AT89C5130A/31A-M is the standard C52 Timer 2. It is a 16-bit timer/counter: the count is maintained by two cascaded eight-bit timer registers, TH2 and TL2. It is controlled by T2CON (Table 13-1) and T2MOD (Table 13-2) registers. Timer 2 operation is similar to Timer 0 and Timer 1. C/T2 selects FOSC/12 (timer operation) or external pin T2 (counter operation) as the timer clock input. Setting TR2 allows TL2 to be incremented by the selected input. Timer 2 has 3 operating modes: capture, auto reload and Baud Rate Generator. These modes are selected by the combination of RCLK, TCLK and CP/RL2 (T2CON). Refer to the Atmel 8-bit microcontroller hardware documentation for the description of Capture and Baud Rate Generator Modes. Timer 2 includes the following enhancements: • Auto-reload mode with up or down counter • Programmable Clock-output 13.1 Auto-reload Mode The Auto-reload mode configures Timer 2 as a 16-bit timer or event counter with automatic reload. If DCEN bit in T2MOD is cleared, Timer 2 behaves as in 80C52 (refer to the Atmel 8-bit microcontroller hardware description). If DCEN bit is set, Timer 2 acts as an Up/down timer/counter as shown in Figure 13-1. In this mode the T2EX pin controls the direction of count. When T2EX is high, Timer 2 counts up. Timer overflow occurs at FFFFh which sets the TF2 flag and generates an interrupt request. The overflow also causes the 16-bit value in RCAP2H and RCAP2L registers to be loaded into the timer registers TH2 and TL2. When T2EX is low, Timer 2 counts down. Timer underflow occurs when the count in the timer registers TH2 and TL2 equals the value stored in RCAP2H and RCAP2L registers. The underflow sets TF2 flag and reloads FFFFh into the timer registers. The EXF2 bit toggles when Timer 2 overflows or underflows according to the direction of the count. EXF2 does not generate any interrupt. This bit can be used to provide 17-bit resolution. 53 4337K–USB–04/08 Figure 13-1. Auto-reload Mode Up/Down Counter (DCEN = 1) FCLK PERIPH :6 0 1 T2 C/T2 T2CON TR2 T2CON (DOWN COUNTING RELOAD VALUE) T2EX: FFh (8-bit) FFh (8-bit) if DCEN = 1, 1 = UP if DCEN = 1, 0 = DOWN if DCEN = 0, up counting TOGGLE T2CON EXF2 TL2 (8-bit) TH2 (8-bit) TF2 T2CON Timer 2 INTERRUPT RCAP2L (8-bit) RCAP2H (8-bit) (UP COUNTING RELOAD VALUE) 13.2 Programmable Clock Output In the Clock-out mode, Timer 2 operates as a 50%-duty-cycle, programmable clock generator (See Figure 13-2). The input clock increments TL2 at frequency FCLK PERIPH/2. The timer repeatedly counts to overflow from a loaded value. At overflow, the contents of RCAP2H and RCAP2L registers are loaded into TH2 and TL2. In this mode, Timer 2 overflows do not generate interrupts. The following formula gives the Clock-out frequency as a function of the system oscillator frequency and the value in the RCAP2H and RCAP2L registers F CLKPERIPH C lock – OutFrequency = ---------------------------------------------------------------------------------------4 × ( 65536 – RCAP 2 H ⁄ RCAP 2 L ) For a 16 MHz system clock, Timer 2 has a programmable frequency range of 61 Hz (FCLK PERIPH/216) to 4 MHz (FCLK PERIPH/4). The generated clock signal is brought out to T2 pin (P1.0). Timer 2 is programmed for the Clock-out mode as follows: • Set T2OE bit in T2MOD register. • Clear C/T2 bit in T2CON register. • Determine the 16-bit reload value from the formula and enter it in RCAP2H/RCAP2L registers. • Enter a 16-bit initial value in timer registers TH2/TL2. It can be the same as the reload value or a different one depending on the application. • To start the timer, set TR2 run control bit in T2CON register. 54 AT89C5130A/31A-M 4337K–USB–04/08 AT89C5130A/31A-M It is possible to use Timer 2 as a baud rate generator and a clock generator simultaneously. For this configuration, the baud rates and clock frequencies are not independent since both functions use the values in the RCAP2H and RCAP2L registers. Figure 13-2. Clock-out Mode C/T2 = 0 FCLK PERIPH TR2 T2CON TL2 (8-bit) TH2 (8-bit) OVERFLOW RCAP2L (8-bit) Toggle T2 Q D RCAP2H (8-bit) T2OE T2MOD T2EX EXEN2 T2CON EXF2 T2CON Timer 2 INTERRUPT 55 4337K–USB–04/08 Table 13-1. 7 TF2 Bit Number T2CON Register T2CON - Timer 2 Control Register (C8h) 6 EXF2 Bit Mnemonic Description Timer 2 overflow Flag Must be cleared by software. Set by hardware on Timer 2 overflow, if RCLK = 0 and TCLK = 0. Timer 2 External Flag Set when a capture or a reload is caused by a negative transition on T2EX pin if EXEN2 = 1. When set, causes the CPU to vector to Timer 2 interrupt routine when Timer 2 interrupt is enabled. Must be cleared by software. EXF2 doesn’t cause an interrupt in Up/down counter mode (DCEN = 1). Receive Clock bit Cleared to use Timer 1 overflow as receive clock for serial port in mode 1 or 3. Set to use Timer 2 overflow as receive clock for serial port in mode 1 or 3. Transmit Clock bit Cleared to use Timer 1 overflow as transmit clock for serial port in mode 1 or 3. Set to use Timer 2 overflow as transmit clock for serial port in mode 1 or 3. Timer 2 External Enable bit Cleared to ignore events on T2EX pin for Timer 2 operation. Set to cause a capture or reload when a negative transition on T2EX pin is detected, if Timer 2 is not used to clock the serial port. Timer 2 Run control bit Cleared to turn off Timer 2. Set to turn on Timer 2. Timer/Counter 2 select bit Cleared for timer operation (input from internal clock system: FCLK PERIPH). Set for counter operation (input from T2 input pin, falling edge trigger). Must be 0 for clock out mode. Timer 2 Capture/Reload bit If RCLK = 1 or TCLK = 1, CP/RL2# is ignored and timer is forced to Auto-reload on Timer 2 overflow. Cleared to Auto-reload on Timer 2 overflows or negative transitions on T2EX pin if EXEN2 = 1. Set to capture on negative transitions on T2EX pin if EXEN2 = 1. 5 RCLK 4 TCLK 3 EXEN2 2 TR2 1 C/T2# 0 CP/RL2# 7 TF2 6 EXF2 5 RCLK 4 TCLK 3 EXEN2 2 TR2 1 C/T2# 0 CP/RL2# Reset Value = 0000 0000b Bit addressable 56 AT89C5130A/31A-M 4337K–USB–04/08 AT89C5130A/31A-M Table 13-2. 7 Bit Number 7 T2MOD Register T2MOD - Timer 2 Mode Control Register (C9h) 6 Bit Mnemonic Description Reserved The value read from this bit is indeterminate. Do not set this bit. Reserved The value read from this bit is indeterminate. Do not set this bit. Reserved The value read from this bit is indeterminate. Do not set this bit. Reserved The value read from this bit is indeterminate. Do not set this bit. Reserved The value read from this bit is indeterminate. Do not set this bit. Reserved The value read from this bit is indeterminate. Do not set this bit. Timer 2 Output Enable bit Cleared to program P1.0/T2 as clock input or I/O port. Set to program P1.0/T2 as clock output. Down Counter Enable bit Cleared to disable Timer 2 as up/down counter. Set to enable Timer 2 as up/down counter. 5 4 3 2 1 T2OE 0 DCEN 6 - 5 - 4 - 3 - 2 - 1 T2OE 0 DCEN Reset Value = XXXX XX00b Not bit addressable 57 4337K–USB–04/08 14. Programmable Counter Array (PCA) The PCA provides more timing capabilities with less CPU intervention than the standard timer/counters. Its advantages include reduced software overhead and improved accuracy. The PCA consists of a dedicated timer/counter which serves as the time base for an array of five compare/capture modules. Its clock input can be programmed to count any one of the following signals: ÷6 • Peripheral clock frequency (FCLK PERIPH) ÷ 2 • Peripheral clock frequency (FCLK PERIPH) • Timer 0 overflow • External input on ECI (P1.2) Each compare/capture modules can be programmed in any one of the following modes: • rising and/or falling edge capture, • software timer • high-speed output, or • pulse width modulator Module 4 can also be programmed as a watchdog timer (see Section "PCA Watchdog Timer", page 68). When the compare/capture modules are programmed in the capture mode, software timer, or high speed output mode, an interrupt can be generated when the module executes its function. All five modules plus the PCA timer overflow share one interrupt vector. The PCA timer/counter and compare/capture modules share Port 1 for external I/O. These pins are listed below. If the port pin is not used for the PCA, it can still be used for standard I/O. PCA Component 16-bit Counter 16-bit Module 0 16-bit Module 1 16-bit Module 2 16-bit Module 3 16-bit Module 4 External I/O Pin P1.2/ECI P1.3/CEX0 P1.4/CEX1 P1.5/CEX2 P1.6/CEX3 P1.7/CEX4 The PCA timer is a common time base for all five modules (see Figure 14-1). The timer count source is determined from the CPS1 and CPS0 bits in the CMOD register (Table 14-1) and can be programmed to run at: • 1/6 the peripheral clock frequency (FCLK PERIPH). • 1/2 the peripheral clock frequency (FCLK PERIPH). • The Timer 0 overflow • The input on the ECI pin (P1.2) 58 AT89C5130A/31A-M 4337K–USB–04/08 AT89C5130A/31A-M Figure 14-1. PCA Timer/Counter To PCA modules FCLK PERIPH/6 FCLK PERIPH/2 T0 OVF P1.2 overflow CH CL 16 Bit Up Counter It CIDL Idle WDTE CPS1 CPS0 ECF CMOD 0xD9 CF CR CCF4 CCF3 CCF2 CCF1 CCF0 CCON 0xD8 Table 14-1. 7 CIDL Bit Number CMOD Register CMOD - PCA Counter Mode Register (D9h) 6 WDTE Bit Mnemonic Description Counter Idle Control 5 4 3 2 CPS1 1 CPS0 0 ECF 7 CIDL Cleared to program the PCA Counter to continue functioning during idle Mode. Set to program PCA to be gated off during idle. Watchdog Timer Enable 6 WDTE Cleared to disable Watchdog Timer function on PCA Module 4. Set to enable Watchdog Timer function on PCA Module 4. 5 - Reserved The value read from this bit is indeterminate. Do not set this bit. Reserved The value read from this bit is indeterminate. Do not set this bit. Reserved The value read from this bit is indeterminate. Do not set this bit. PCA Count Pulse Select CPS1CPS0 0 0 Selected PCA input Internal clock fCLK PERIPH/6 Internal clock fCLK PERIPH/2 Timer 0 Overflow External clock at ECI/P1.2 pin (max rate = fCLK PERIPH/ 4) 4 - 3 2 CPS1 1 CPS0 0 1 1 1 0 1 0 ECF PCA Enable Counter Overflow Interrupt Cleared to disable CF bit in CCON to inhibit an interrupt. Set to enable CF bit in CCON to generate an interrupt. 59 4337K–USB–04/08 Reset Value = 00XX X000b Not bit addressable The CMOD register includes three additional bits associated with the PCA (See Figure 14-1 and Table 14-1). • The CIDL bit allows the PCA to stop during idle mode. • The WDTE bit enables or disables the watchdog function on module 4. • The ECF bit when set causes an interrupt and the PCA overflow flag CF (in the CCON SFR) to be set when the PCA timer overflows. The CCON register contains the run control bit for the PCA and the flags for the PCA timer (CF) and each module (see Table 14-2). • Bit CR (CCON.6) must be set by software to run the PCA. The PCA is shut off by clearing this bit. • Bit CF: The CF bit (CCON.7) is set when the PCA counter overflows and an interrupt will be generated if the ECF bit in the CMOD register is set. The CF bit can only be cleared by software. • Bits 0 through 4 are the flags for the modules (bit 0 for module 0, bit 1 for module 1, etc.) and are set by hardware when either a match or a capture occurs. These flags can only be cleared by software. Table 14-2. 7 CF Bit Number Bit Mnemonic Description PCA Counter Overflow flag 7 CF Set by hardware when the counter rolls over. CF flags an interrupt if bit ECF in CMOD is set. CF may be set by either hardware or software but can only be cleared by software. PCA Counter Run control bit 6 CR Must be cleared by software to turn the PCA counter off. Set by software to turn the PCA counter on. Reserved The value read from this bit is indeterminate. Do not set this bit. PCA Module 4 interrupt flag 4 CCF4 Must be cleared by software. Set by hardware when a match or capture occurs. PCA Module 3 interrupt flag 3 CCF3 Must be cleared by software. Set by hardware when a match or capture occurs. PCA Module 2 interrupt flag 2 CCF2 Must be cleared by software. Set by hardware when a match or capture occurs. CCON Register CCON - PCA Counter Control Register (D8h) 6 CR 5 – 4 CCF4 3 CCF3 2 CCF2 1 CCF1 0 CCF0 5 – 60 AT89C5130A/31A-M 4337K–USB–04/08 AT89C5130A/31A-M Bit Number Bit Mnemonic Description PCA Module 1 Interrupt Flag 1 CCF1 Must be cleared by software. Set by hardware when a match or capture occurs. PCA Module 0 Interrupt Flag 0 CCF0 Must be cleared by software. Set by hardware when a match or capture occurs. Reset Value = 000X 0000b Not bit addressable The watchdog timer function is implemented in module 4 (See Figure 14-4). The PCA interrupt system is shown in Figure 14-2. Figure 14-2. PCA Interrupt System CF PCA Timer/Counter CR CCF4 CCF3 CCF2 CCF1 CCF0 CCON 0xD8 Module 0 Module 1 To Interrupt priority decoder Module 2 Module 3 Module 4 CMOD.0 ECF ECCFn CCAPMn.0 IE.6 EC IE.7 EA PCA Modules: each one of the five compare/capture modules has six possible functions. It can perform: • 16-bit capture, positive-edge triggered • 16-bit capture, negative-edge triggered • 16-bit capture, both positive and negative-edge triggered • 16-bit Software Timer • 16-bit High-speed Output • 8-bit Pulse Width Modulator In addition, module 4 can be used as a Watchdog Timer. Each module in the PCA has a special function register associated with it. These registers are: CCAPM0 for module 0, CCAPM1 for module 1, etc. (see Table 14-3). The registers contain the bits that control the mode that each module will operate in. 61 4337K–USB–04/08 • The ECCF bit (CCAPMn.0 where n = 0, 1, 2, 3, or 4 depending on the module) enables the CCF flag in the CCON SFR to generate an interrupt when a match or compare occurs in the associated module. • PWM (CCAPMn.1) enables the pulse width modulation mode. • The TOG bit (CCAPMn.2) when set causes the CEX output associated with the module to toggle when there is a match between the PCA counter and the module's capture/compare register. • The match bit MAT (CCAPMn.3) when set will cause the CCFn bit in the CCON register to be set when there is a match between the PCA counter and the module's capture/compare register. • The next two bits CAPN (CCAPMn.4) and CAPP (CCAPMn.5) determine the edge that a capture input will be active on. The CAPN bit enables the negative edge, and the CAPP bit enables the positive edge. If both bits are set both edges will be enabled and a capture will occur for either transition. • The last bit in the register ECOM (CCAPMn.6) when set enables the comparator function. Table 14-4 shows the CCAPMn settings for the various PCA functions. Table 14-3. CCAPMn Registers (n = 0-4) CCAPM0 - PCA Module 0 Compare/Capture Control Register (0DAh) CCAPM1 - PCA Module 1 Compare/Capture Control Register (0DBh) CCAPM2 - PCA Module 2 Compare/Capture Control Register (0DCh) CCAPM3 - PCA Module 3 Compare/Capture Control Register (0DDh) CCAPM4 - PCA Module 4 Compare/Capture Control Register (0DEh) 7 Bit Number 7 6 ECOMn Bit Mnemonic Description Reserved The value read from this bit is indeterminate. Do not set this bit. Enable Comparator 6 ECOMn Cleared to disable the comparator function. Set to enable the comparator function. Capture Positive 5 CAPPn Cleared to disable positive edge capture. Set to enable positive edge capture. Capture Negative 4 CAPNn Cleared to disable negative edge capture. Set to enable negative edge capture. Match 3 MATn When MATn = 1, a match of the PCA counter with this module's compare/capture register causes the CCFn bit in CCON to be set, flagging an interrupt. Toggle 2 TOGn When TOGn = 1, a match of the PCA counter with this module's compare/capture register causes the CEXn pin to toggle. 5 CAPPn 4 CAPNn 3 MATn 2 TOGn 1 PWMn 0 ECCFn 62 AT89C5130A/31A-M 4337K–USB–04/08 AT89C5130A/31A-M Bit Number Bit Mnemonic Description Pulse Width Modulation Mode 1 PWMn Cleared to disable the CEXn pin to be used as a pulse width modulated output. Set to enable the CEXn pin to be used as a pulse width modulated output. Enable CCF Interrupt 0 ECCFn Cleared to disable compare/capture flag CCFn in the CCON register to generate an interrupt. Set to enable compare/capture flag CCFn in the CCON register to generate an interrupt. Reset Value = X000 0000b Not bit addressable Table 14-4. ECOMn 0 X PCA Module Modes (CCAPMn Registers) CAPPn 0 1 CAPNn 0 0 MATn 0 0 TOGn 0 0 PWMm ECCFn Module Function 0 0 0 X No Operation 16-bit capture by a positive-edge trigger on CEXn 16-bit capture by a negative trigger on CEXn 16-bit capture by a transition on CEXn 16-bit Software Timer/Compare mode. 16-bit High Speed Output 8-bit PWM Watchdog Timer (module 4 only) X 0 1 0 0 0 X X 1 1 0 0 0 X 1 1 1 1 0 0 0 0 0 0 0 0 1 1 0 1 0 1 0 X 0 0 1 0 X X 0 X There are two additional registers associated with each of the PCA modules. They are CCAPnH and CCAPnL and these are the registers that store the 16-bit count when a capture occurs or a compare should occur. When a module is used in the PWM mode these registers are used to control the duty cycle of the output (see Table 14-5 and Table 14-6) Table 14-5. CCAPnH Registers (n = 0-4) CCAP0H - PCA Module 0 Compare/Capture Control Register High (0FAh) CCAP1H - PCA Module 1 Compare/Capture Control Register High (0FBh) CCAP2H - PCA Module 2 Compare/Capture Control Register High (0FCh) CCAP3H - PCA Module 3 Compare/Capture Control Register High (0FDh) CCAP4H - PCA Module 4 Compare/Capture Control Register High (0FEh) 7 Bit Number 7-0 6 Bit Mnemonic Description PCA Module n Compare/Capture Control CCAPnH Value 5 4 3 2 1 0 - 63 4337K–USB–04/08 Reset Value = XXXX XXXXb Not bit addressable Table 14-6. CCAPnL Registers (n = 0-4) CCAP0L - PCA Module 0 Compare/Capture Control Register Low (0EAh) CCAP1L - PCA Module 1 Compare/Capture Control Register Low (0EBh) CCAP2L - PCA Module 2 Compare/Capture Control Register Low (0ECh) CCAP3L - PCA Module 3 Compare/Capture Control Register Low (0EDh) CCAP4L - PCA Module 4 Compare/Capture Control Register Low (0EEh) 7 Bit Number 7-0 6 Bit Mnemonic Description PCA Module n Compare/Capture Control CCAPnL Value 5 4 3 2 1 0 - Reset Value = XXXX XXXXb Not bit addressable Table 14-7. CH Register CH - PCA Counter Register High (0F9h) 7 Bit Number 7-0 6 Bit Mnemonic Description PCA counter CH Value 5 4 3 2 1 0 - Reset Value = 0000 0000b Not bit addressable Table 14-8. CL Register CL - PCA Counter Register Low (0E9h) 7 Bit Number 7-0 6 Bit Mnemonic Description PCA Counter CL Value 5 4 3 2 1 0 - Reset Value = 0000 0000b Not bit addressable 64 AT89C5130A/31A-M 4337K–USB–04/08 AT89C5130A/31A-M 14.1 PCA Capture Mode To use one of the PCA modules in the capture mode either one or both of the CCAPM bits CAPN and CAPP for that module must be set. The external CEX input for the module (on port 1) is sampled for a transition. When a valid transition occurs the PCA hardware loads the value of the PCA counter registers (CH and CL) into the module's capture registers (CCAPnL and CCAPnH). If the CCFn bit for the module in the CCON SFR and the ECCFn bit in the CCAPMn SFR are set then an interrupt will be generated (see Figure 14-3). Figure 14-3. PCA Capture Mode CF CR CCF4 CCF3 CCF2 CCF1 CCF0 CCON 0xD8 PCA IT PCA Counter/Timer Cex.n Capture CH CL CCAPnH CCAPnL ECOMn CAPPn CAPNn MATn TOGn PWMn ECCFn CCAPMn, n = 0 to 4 0xDA to 0xDE 14.2 16-bit Software Timer/Compare Mode The PCA modules can be used as software timers by setting both the ECOM and MAT bits in the modules CCAPMn register. The PCA timer will be compared to the module's capture registers and when a match occurs an interrupt will occur if the CCFn (CCON SFR) and the ECCFn (CCAPMn SFR) bits for the module are both set (see Figure 14-4). 65 4337K–USB–04/08 Figure 14-4. PCA Compare Mode and PCA Watchdog Timer CCON CF Write to CCAPnL Write to CCAPnH 1 0 Enable 16-bit Comparator RESET(1) Reset PCA IT CCAPnH CCAPnL Match CR CCF4 CCF3 CCF2 CCF1 CCF0 0xD8 CH CL PCA Counter/Timer ECOMn CAPPn CAPNn MATn TOGn PWMn ECCFn CCAPMn, n = 0 to 4 0xDA to 0xDE CIDL WDTE CPS1 CPS0 ECF CMOD 0xD9 Note: 1. Only for Module 4 Before enabling ECOM bit, CCAPnL and CCAPnH should be set with a non zero value, otherwise an unwanted match could happen. Writing to CCAPnH will set the ECOM bit. Once ECOM set, writing CCAPnL will clear ECOM so that an unwanted match doesn’t occur while modifying the compare value. Writing to CCAPnH will set ECOM. For this reason, user software should write CCAPnL first, and then CCAPnH. Of course, the ECOM bit can still be controlled by accessing to CCAPMn register. 14.3 High Speed Output Mode In this mode, the CEX output (on port 1) associated with the PCA module will toggle each time a match occurs between the PCA counter and the module's capture registers. To activate this mode the TOG, MAT, and ECOM bits in the module's CCAPMn SFR must be set (see Figure 14-5). A prior write must be done to CCAPnL and CCAPnH before writing the ECOMn bit. 66 AT89C5130A/31A-M 4337K–USB–04/08 AT89C5130A/31A-M Figure 14-5. PCA High-speed Output Mode CCON CF CR CCF4 CCF3 CCF2 CCF1 CCF0 0xD8 Write to CCAPnL Reset PCA IT Write to CCAPnH 0 CCAPnH Enable 16-bit Comparator CCAPnL Match 1 CH CL CEXn PCA counter/timer CCAPMn, n = 0 to 4 0xDA to 0xDE ECOMn CAPPn CAPNn MATn TOGn PWMn ECCFn Before enabling ECOM bit, CCAPnL and CCAPnH should be set with a non zero value, otherwise an unwanted match could happen. Once ECOM set, writing CCAPnL will clear ECOM so that an unwanted match doesn’t occur while modifying the compare value. Writing to CCAPnH will set ECOM. For this reason, user software should write CCAPnL first, and then CCAPnH. Of course, the ECOM bit can still be controlled by accessing to CCAPMn register. 14.4 Pulse Width Modulator Mode All of the PCA modules can be used as PWM outputs. Figure 14-6 shows the PWM function. The frequency of the output depends on the source for the PCA timer. All of the modules will have the same frequency of output because they all share the PCA timer. The duty cycle of each module is independently variable using the module's capture register CCAPLn. When the value of the PCA CL SFR is less than the value in the module's CCAPLn SFR the output will be low, when it is equal to or greater than the output will be high. When CL overflows from FF to 00, CCAPLn is reloaded with the value in CCAPHn. This allows updating the PWM without glitches. The PWM and ECOM bits in the module's CCAPMn register must be set to enable the PWM mode. 67 4337K–USB–04/08 Figure 14-6. PCA PWM Mode CCAPnH Overflow CCAPnL “0” Enable 8-bit Comparator < ≥ “1” CEXn CL PCA Counter/Timer ECOMn CAPPn CAPNn MATn TOGn PWMn ECCFn CCAPMn, n = 0 to 4 0xDA to 0xDE 14.5 PCA Watchdog Timer An on-board watchdog timer is available with the PCA to improve the reliability of the system without increasing chip count. Watchdog timers are useful for systems that are susceptible to noise, power glitches, or electrostatic discharge. Module 4 is the only PCA module that can be programmed as a watchdog. However, this module can still be used for other modes if the watchdog is not needed. Figure 14-4 shows a diagram of how the watchdog works. The user pre-loads a 16-bit value in the compare registers. Just like the other compare modes, this 16-bit value is compared to the PCA timer value. If a match is allowed to occur, an internal reset will be generated. This will not cause the RST pin to be driven low. In order to hold off the reset, the user has three options: 1. Periodically change the compare value so it will never match the PCA timer 2. Periodically change the PCA timer value so it will never match the compare values, or 3. Disable the watchdog by clearing the WDTE bit before a match occurs and then reenable it The first two options are more reliable because the watchdog timer is never disabled as in option #3. If the program counter ever goes astray, a match will eventually occur and cause an internal reset. The second option is also not recommended if other PCA modules are being used. Remember, the PCA timer is the time base for all modules; changing the time base for other modules would not be a good idea. Thus, in most applications the first solution is the best option. This watchdog timer won’t generate a reset out on the reset pin. 68 AT89C5130A/31A-M 4337K–USB–04/08 AT89C5130A/31A-M 15. Serial I/O Port The serial I/O port in the AT89C5130A/31A-M is compatible with the serial I/O port in the 80C52. It provides both synchronous and asynchronous communication modes. It operates as an Universal Asynchronous Receiver and Transmitter (UART) in three full-duplex modes (modes 1, 2 and 3). Asynchronous transmission and reception can occur simultaneously and at different baud rates. Serial I/O port includes the following enhancements: • Framing error detection • Automatic address recognition 15.1 Framing Error Detection Framing bit error detection is provided for the three asynchronous modes (modes 1, 2 and 3). To enable the framing bit error detection feature, set SMOD0 bit in PCON register (see Figure 151). Figure 15-1. Framing Error Block Diagram SM0/FE SM1 SM2 REN TB8 RB8 TI RI SCON (98h) Set FE Bit if Stop Bit is 0 (framing error) (SMOD0 = 1) SM0 to UART Mode Control (SMOD0 = 0) SMOD1 SMOD0 POF GF1 GF0 PD IDL PCON (87h) To UART Framing Error Control When this feature is enabled, the receiver checks each incoming data frame for a valid stop bit. An invalid stop bit may result from noise on the serial lines or from simultaneous transmission by two CPUs. If a valid stop bit is not found, the Framing Error bit (FE) in SCON register (See Table 15-1) bit is set. Software may examine FE bit after each reception to check for data errors. Once set, only software or a reset can clear FE bit. Subsequently received frames with valid stop bits cannot clear FE bit. When FE feature is enabled, RI rises on stop bit instead of the last data bit (See Figure 15-2 and Figure 15-3). Figure 15-2. UART Timings in Mode 1 RXD Start Bit RI SMOD0 = X FE SMOD0 = 1 D0 D1 D2 D3 D4 D5 D6 D7 Stop Bit Data Byte 69 4337K–USB–04/08 Figure 15-3. UART Timings in Modes 2 and 3 RXD Start Bit RI SMOD0 = 0 RI SMOD0 = 1 FE SMOD0 = 1 D0 D1 D2 D3 D4 D5 D6 D7 D8 Ninth Stop Bit Bit Data Byte 15.2 Automatic Address Recognition The automatic address recognition feature is enabled when the multiprocessor communication feature is enabled (SM2 bit in SCON register is set). Implemented in hardware, automatic address recognition enhances the multiprocessor communication feature by allowing the serial port to examine the address of each incoming command frame. Only when the serial port recognizes its own address, the receiver sets RI bit in SCON register to generate an interrupt. This ensures that the CPU is not interrupted by command frames addressed to other devices. If desired, you may enable the automatic address recognition feature in mode 1. In this configuration, the stop bit takes the place of the ninth data bit. Bit RI is set only when the received command frame address matches the device’s address and is terminated by a valid stop bit. To support automatic address recognition, a device is identified by a given address and a broadcast address. Note: The multiprocessor communication and automatic address recognition features cannot be enabled in mode 0 (i.e., setting SM2 bit in SCON register in mode 0 has no effect). 15.2.1 Given Address Each device has an individual address that is specified in SADDR register; the SADEN register is a mask byte that contains don’t care bits (defined by zeros) to form the device’s given address. The don’t care bits provide the flexibility to address one or more slaves at a time. The following example illustrates how a given address is formed. To address a device by its individual address, the SADEN mask byte must be 1111 1111b. For example: SADDR0101 0110b SADEN1111 1100b Given0101 01XXb The following is an example of how to use given addresses to address different slaves: Slave A:SADDR1111 0001b SADEN1111 1010b Given1111 0X0Xb Slave B:SADDR1111 0011b SADEN1111 1001b Given1111 0XX1b 70 AT89C5130A/31A-M 4337K–USB–04/08 AT89C5130A/31A-M Slave C:SADDR1111 0011b SADEN1111 1101b Given1111 00X1b The SADEN byte is selected so that each slave may be addressed separately. For slave A, bit 0 (the LSB) is a don’t care bit; for slaves B and C, bit 0 is a 1. To communicate with slave A only, the master must send an address where bit 0 is clear (e.g. 1111 0000b). For slave A, bit 1 is a 1; for slaves B and C, bit 1 is a don’t care bit. To communicate with slaves B and C, but not slave A, the master must send an address with bits 0 and 1 both set (e.g. 1111 0011b). To communicate with slaves A, B and C, the master must send an address with bit 0 set, bit 1 clear, and bit 2 clear (e.g. 1111 0001b). 15.2.2 Broadcast Address A broadcast address is formed from the logical OR of the SADDR and SADEN registers with zeros defined as don’t care bits, e.g.: SADDR0101 0110b SADEN1111 1100b Broadcast = SADDR OR SADEN1111 111Xb The use of don’t care bits provides flexibility in defining the broadcast address, in most applications, a broadcast address is FFh. The following is an example of using broadcast addresses: Slave A:SADDR1111 0001b SADEN1111 1010b Broadcast1111 1X11b, Slave B:SADDR1111 0011b SADEN1111 1001b Broadcast1111 1X11B, Slave C:SADDR = 1111 0011b SADEN1111 1101b Broadcast1111 1111b For slaves A and B, bit 2 is a don’t care bit; for slave C, bit 2 is set. To communicate with all of the slaves, the master must send an address FFh. To communicate with slaves A and B, but not slave C, the master can send and address FBh. 15.2.3 Reset Addresses On reset, the SADDR and SADEN registers are initialized to 00h, i.e. the given and broadcast addresses are XXXX XXXXb (all don’t care bits). This ensures that the serial port will reply to any address, and so, that it is backwards compatible with the 80C51 microcontrollers that do not support automatic address recognition. 71 4337K–USB–04/08 SADEN - Slave Address Mask Register (B9h) 7 6 5 4 3 2 1 0 Reset Value = 0000 0000b Not bit addressable SADDR - Slave Address Register (A9h) 7 6 5 4 3 2 1 0 Reset Value = 0000 0000b Not bit addressable 15.3 Baud Rate Selection for UART for Mode 1 and 3 The Baud Rate Generator for transmit and receive clocks can be selected separately via the T2CON and BDRCON registers. Figure 15-4. Baud Rate Selection TIMER1 TIMER2 0 1 RCLK INT_BRG RBCK TIMER_BRG_RX 0 1 / 16 Rx Clock TIMER1 TIMER2 0 1 TCLK TIMER_BRG_TX 0 1 / 16 Tx Clock INT_BRG TBCK 72 AT89C5130A/31A-M 4337K–USB–04/08 AT89C5130A/31A-M 15.3.1 Baud Rate Selection Table for UART TCLK (T2CON) 0 1 0 1 X X 0 1 X RCLK (T2CON) 0 0 1 1 0 1 X X X TBCK (BDRCON) 0 0 0 0 1 1 0 0 1 RBCK (BDRCON) 0 0 0 0 0 0 1 1 1 Clock Source UART Tx Timer 1 Timer 2 Timer 1 Timer 2 INT_BRG INT_BRG Timer 1 Timer 2 INT_BRG Clock Source UART Rx Timer 1 Timer 1 Timer 2 Timer 2 Timer 1 Timer 2 INT_BRG INT_BRG INT_BRG 15.3.2 Internal Baud Rate Generator (BRG) When the internal Baud Rate Generator is used, the Baud Rates are determined by the BRG overflow depending on the BRL reload value, the value of SPD bit (Speed Mode) in BDRCON register and the value of the SMOD1 bit in PCON register. Figure 15-5. Internal Baud Rate Peripheral Clock /6 0 1 SPD BRR BRL auto reload counter overflow BRG /2 0 1 SMOD1 INT_BRG • The baud rate for UART is token by formula: Baud_Rate = 2x6 2SMOD1 x FCLK PERIPH (1-SPD) x 16 x [256 - (BRL)] (BRL) = 256 2x6 2SMOD1 x FCLK PERIPH (1-SPD) x 16 x Baud_Rate Table 15-1. 7 FE/SM0 SCON Register – SCON Serial Control Register (98h) 6 SM1 5 SM2 4 REN 3 TB8 2 RB8 1 TI 0 RI 73 4337K–USB–04/08 Bit Number Bit Mnemonic Description Framing Error bit (SMOD0 = 1) Clear to reset the error state, not cleared by a valid stop bit. Set by hardware when an invalid stop bit is detected. SMOD0 must be set to enable access to the FE bit Serial port Mode bit 0 Refer to SM1 for serial port mode selection. SMOD0 must be cleared to enable access to the SM0 bit Serial port Mode bit 1 SM0SM1Mode DescriptionBaud Rate 00 0 Shift RegisterFCPU PERIPH/6 01 1 8-bit UARTVariable 10 2 9-bit UARTFCPU PERIPH/32 or/16 1 1 3 9-bit UARTVariable FE 7 SM0 6 SM1 5 SM2 Serial port Mode 2 bit/Multiprocessor Communication Enable bit Clear to disable multiprocessor communication feature. Set to enable multiprocessor communication feature in mode 2 and 3, and eventually mode 1. This bit should be cleared in mode 0. Reception Enable bit Clear to disable serial reception. Set to enable serial reception. Transmitter Bit 8/Ninth bit to Transmit in Modes 2 and 3 4 REN 3 TB8 Clear to transmit a logic 0 in the 9th bit. Set to transmit a logic 1 in the 9th bit. Receiver Bit 8/Ninth bit received in modes 2 and 3 Cleared by hardware if 9th bit received is a logic 0. Set by hardware if 9th bit received is a logic 1. In mode 1, if SM2 = 0, RB8 is the received stop bit. In mode 0 RB8 is not used. Transmit Interrupt flag Clear to acknowledge interrupt. Set by hardware at the end of the 8th bit time in mode 0 or at the beginning of the stop bit in the other modes. Receive Interrupt flag Clear to acknowledge interrupt. Set by hardware at the end of the 8th bit time in mode 0, see Figure 15-2. and Figure 153. in the other modes. 2 RB8 1 TI 0 RI Reset Value = 0000 0000b Bit addressable 74 AT89C5130A/31A-M 4337K–USB–04/08 AT89C5130A/31A-M Example of computed value when X2 = 1, SMOD1 = 1, SPD = 1 Baud Rates FOSC = 16.384 MHz BRL 115200 57600 38400 28800 19200 9600 4800 247 238 229 220 203 149 43 Error (%) 1.23 1.23 1.23 1.23 0.63 0.31 1.23 BRL 243 230 217 204 178 100 FOSC = 24 MHz Error (%) 0.16 0.16 0.16 0.16 0.16 0.16 - Example of computed value when X2 = 0, SMOD1 = 0, SPD = 0 FOSC = 16.384 MHz Baud Rates 4800 2400 1200 600 BRL 247 238 220 185 Error (%) 1.23 1.23 1.23 0.16 BRL 243 230 202 152 FOSC = 24 MHz Error (%) 0.16 0.16 3.55 0.16 The baud rate generator can be used for mode 1 or 3 (refer to Figure 15-4.), but also for mode 0 for UART, thanks to the bit SRC located in BDRCON register (Table 15-4.) 15.4 UART Registers SADEN - Slave Address Mask Register for UART (B9h) 7 – 6 – 5 – 4 – 3 – 2 – 1 – 0 – Reset Value = 0000 0000b SADDR - Slave Address Register for UART (A9h) 7 – 6 – 5 – 4 – 3 – 2 – 1 – 0 – Reset Value = 0000 0000b SBUF - Serial Buffer Register for UART (99h) 7 – 6 – 5 – 4 – 3 – 2 – 1 – 0 – Reset Value = XXXX XXXXb 75 4337K–USB–04/08 BRL - Baud Rate Reload Register for the internal baud rate generator, UART (9Ah) 7 – 6 – 5 – 4 – 3 – 2 – 1 – 0 – Reset Value = 0000 0000b Table 15-2. T2CON Register T2CON - Timer 2 Control Register (C8h) 7 TF2 Bit Number 6 EXF2 Bit Mnemonic Description Timer 2 overflow Flag Must be cleared by software. Set by hardware on Timer 2 overflow, if RCLK = 0 and TCLK = 0. Timer 2 External Flag Set when a capture or a reload is caused by a negative transition on T2EX pin if EXEN2 = 1. When set, causes the CPU to vector to Timer 2 interrupt routine when Timer 2 interrupt is enabled. Must be cleared by software. EXF2 doesn’t cause an interrupt in Up/down counter mode (DCEN = 1) Receive Clock bit for UART Cleared to use Timer 1 overflow as receive clock for serial port in mode 1 or 3. Set to use Timer 2 overflow as receive clock for serial port in mode 1 or 3. Transmit Clock bit for UART Cleared to use Timer 1 overflow as transmit clock for serial port in mode 1 or 3. Set to use Timer 2 overflow as transmit clock for serial port in mode 1 or 3. Timer 2 External Enable bit Cleared to ignore events on T2EX pin for Timer 2 operation. Set to cause a capture or reload when a negative transition on T2EX pin is detected, if Timer 2 is not used to clock the serial port. Timer 2 Run control bit Cleared to turn off Timer 2. Set to turn on Timer 2. Timer/Counter 2 select bit Cleared for timer operation (input from internal clock system: FCLK PERIPH). Set for counter operation (input from T2 input pin, falling edge trigger). Must be 0 for clock out mode. Timer 2 Capture/Reload bit If RCLK = 1 or TCLK = 1, CP/RL2# is ignored and timer is forced to Auto-reload on Timer 2 overflow. Cleared to Auto-reload on Timer 2 overflows or negative transitions on T2EX pin if EXEN2 = 1. Set to capture on negative transitions on T2EX pin if EXEN2 = 1. 5 RCLK 4 TCLK 3 EXEN2 2 TR2 1 C/T2# 0 CP/RL2# 7 TF2 6 EXF2 5 RCLK 4 TCLK 3 EXEN2 2 TR2 1 C/T2# 0 CP/RL2# Reset Value = 0000 0000b Bit addressable 76 AT89C5130A/31A-M 4337K–USB–04/08 AT89C5130A/31A-M Table 15-3. PCON Register PCON - Power Control Register (87h) 7 SMOD1 Bit Number 7 6 SMOD0 Bit Mnemonic SMOD1 Description Serial port Mode bit 1 for UART Set to select double baud rate in mode 1, 2 or 3. Serial port Mode bit 0 for UART 6 SMOD0 Cleared to select SM0 bit in SCON register. Set to select FE bit in SCON register. Reserved The value read from this bit is indeterminate. Do not set this bit. Power-Off Flag Cleared to recognize next reset type. Set by hardware when VCC rises from 0 to its nominal voltage. Can also be set by software. General-purpose Flag Cleared by user for general-purpose usage. Set by user for general-purpose usage. General-purpose Flag Cleared by user for general-purpose usage. Set by user for general-purpose usage. Power-down Mode Bit Cleared by hardware when reset occurs. Set to enter power-down mode. Idle Mode Bit Cleared by hardware when interrupt or reset occurs. Set to enter idle mode. 5 4 POF 3 GF1 2 GF0 1 PD 0 IDL 5 - 4 POF 3 GF1 2 GF0 1 PD 0 IDL Reset Value = 00X1 0000b Not bit addressable Power-off flag reset value will be 1 only after a power on (cold reset). A warm reset doesn’t affect the value of this bit. Table 15-4. BDRCON Register BDRCON - Baud Rate Control Register (9Bh) 7 6 5 4 BRR 3 TBCK 2 RBCK 1 SPD 0 SRC 77 4337K–USB–04/08 Bit Number 7 Bit Mnemonic - Description Reserved The value read from this bit is indeterminate. Do not set this bit Reserved The value read from this bit is indeterminate. Do not set this bit Reserved The value read from this bit is indeterminate. Do not set this bit. Baud Rate Run Control bit Cleared to stop the internal Baud Rate Generator. Set to start the internal Baud Rate Generator. Transmission Baud rate Generator Selection bit for UART Cleared to select Timer 1 or Timer 2 for the Baud Rate Generator. Set to select internal Baud Rate Generator. Reception Baud Rate Generator Selection bit for UART Cleared to select Timer 1 or Timer 2 for the Baud Rate Generator. Set to select internal Baud Rate Generator. Baud Rate Speed Control bit for UART Cleared to select the SLOW Baud Rate Generator. Set to select the FAST Baud Rate Generator. Baud Rate Source select bit in Mode 0 for UART 6 - 5 - 4 BRR 3 TBCK 2 RBCK 1 SPD 0 SRC Cleared to select FOSC/12 as the Baud Rate Generator (FCLK PERIPH/6 in X2 mode). Set to select the internal Baud Rate Generator for UARTs in mode 0. Reset Value = XXX0 0000b Not bit addressable 78 AT89C5130A/31A-M 4337K–USB–04/08 AT89C5130A/31A-M 16. Interrupt System 16.1 Overview The AT89C5130A/31A-M has a total of 11 interrupt vectors: two external interrupts (INT0 and INT1), three timer interrupts (timers 0, 1 and 2), the serial port interrupt, SPI interrupt, Keyboard interrupt, USB interrupt and the PCA global interrupt. These interrupts are shown in Figure 16-1. Figure 16-1. Interrupt Control System IPH, IPL 3 INT0 IE0 0 3 TF0 TCON.2 TCON.0 High priority interrupt IT0 0 3 IE1 0 3 Interrupt Polling Sequence, Decreasing From High-to-Low Priority IT1 INT1 TF1 0 3 PCA IT 0 RI TI 3 0 3 0 3 KBD IT 0 3 TWI IT SPI IT 0 USBINT UEPINT 3 0 0 3 TF2 EXF2 Individual Enable Global Disable Low Priority Interrupt Each of the interrupt sources can be individually enabled or disabled by setting or clearing a bit in the Interrupt Enable register (Table 16-2). This register also contains a global disable bit, which must be cleared to disable all interrupts at once. 79 4337K–USB–04/08 Each interrupt source can also be individually programmed to one out of four priority levels by setting or clearing a bit in the Interrupt Priority register (Table 16-3.) and in the Interrupt Priority High register (Table 16-4). Table 16-1. shows the bit values and priority levels associated with each combination. 16.2 Registers The PCA interrupt vector is located at address 0033H, the SPI interrupt vector is located at address 004BH and Keyboard interrupt vector is located at address 003BH. All other vectors addresses are the same as standard C52 devices. Table 16-1. Priority Level Bit Values IPH.x 0 0 1 1 IPL.x 0 1 0 1 Interrupt Level Priority 0 (Lowest) 1 2 3 (Highest) A low-priority interrupt can be interrupted by a high priority interrupt, but not by another low-priority interrupt. A high-priority interrupt can’t be interrupted by any other interrupt source. If two interrupt requests of different priority levels are received simultaneously, the request of higher priority level is serviced. If interrupt requests of the same priority level are received simultaneously, an internal polling sequence determines which request is serviced. Thus within each priority level there is a second priority structure determined by the polling sequence. Table 16-2. IEN0 Register IEN0 - Interrupt Enable Register (A8h) 7 EA 6 EC 5 ET2 4 ES 3 ET1 2 EX1 1 ET0 0 EX0 80 AT89C5130A/31A-M 4337K–USB–04/08 AT89C5130A/31A-M Bit Number Bit Mnemonic Description Enable All interrupt bit Cleared to disable all interrupts. Set to enable all interrupts. PCA interrupt enable bit Cleared to disable. Set to enable. Timer 2 overflow interrupt Enable bit Cleared to disable Timer 2 overflow interrupt. Set to enable Timer 2 overflow interrupt. Serial port Enable bit Cleared to disable serial port interrupt. Set to enable serial port interrupt. Timer 1 overflow interrupt Enable bit Cleared to disable Timer 1 overflow interrupt. Set to enable Timer 1 overflow interrupt. External interrupt 1 Enable bit Cleared to disable external interrupt 1. Set to enable external interrupt 1. Timer 0 overflow interrupt Enable bit Cleared to disable timer 0 overflow interrupt. Set to enable timer 0 overflow interrupt. External interrupt 0 Enable bit Cleared to disable external interrupt 0. Set to enable external interrupt 0. 7 EA 6 EC 5 ET2 4 ES 3 ET1 2 EX1 1 ET0 0 EX0 Reset Value = 0000 0000b Bit addressable Table 16-3. IPL0 Register IPL0 - Interrupt Priority Register (B8h) 7 6 PPCL 5 PT2L 4 PSL 3 PT1L 2 PX1L 1 PT0L 0 PX0L 81 4337K–USB–04/08 Bit Number 7 Bit Mnemonic Description Reserved The value read from this bit is indeterminate. Do not set this bit. PCA interrupt Priority bit Refer to PPCH for priority level. Timer 2 overflow interrupt Priority bit Refer to PT2H for priority level. Serial port Priority bit Refer to PSH for priority level. Timer 1 overflow interrupt Priority bit Refer to PT1H for priority level. External interrupt 1 Priority bit Refer to PX1H for priority level. Timer 0 overflow interrupt Priority bit Refer to PT0H for priority level. External interrupt 0 Priority bit Refer to PX0H for priority level. 6 PPCL 5 PT2L 4 PSL 3 PT1L 2 PX1L 1 PT0L 0 PX0L Reset Value = X000 0000b Bit addressable Table 16-4. IPH0 Register IPH0 - Interrupt Priority High Register (B7h) 7 6 PPCH 5 PT2H 4 PSH 3 PT1H 2 PX1H 1 PT0H 0 PX0H 82 AT89C5130A/31A-M 4337K–USB–04/08 AT89C5130A/31A-M Bit Number 7 Bit Mnemonic Description Reserved The value read from this bit is indeterminate. Do not set this bit. PCA interrupt Priority high bit. PPCH PPCL Priority Level 0 0 Lowest 0 1 1 0 1 1 Highest Timer 2 overflow interrupt Priority High bit PT2H PT2L Priority Level 0 0 Lowest 0 1 1 0 1 1 Highest Serial port Priority High bit PSH PSL Priority Level 0 0 Lowest 0 1 1 0 1 1 Highest Timer 1 overflow interrupt Priority High bit PT1H PT1L Priority Level 0 0 Lowest 0 1 1 0 1 1 Highest External interrupt 1 Priority High bit PX1H PX1L Priority Level 0 0 Lowest 0 1 1 0 1 1 Highest Timer 0 overflow interrupt Priority High bit PT0H PT0L Priority Level 0 0 Lowest 0 1 1 0 1 1 Highest External interrupt 0 Priority High bit PX0H PX0L Priority Level 0 0 Lowest 0 1 1 0 1 1 Highest 6 PPCH 5 PT2H 4 PSH 3 PT1H 2 PX1H 1 PT0H 0 PX0H Reset Value = X000 0000b Not bit addressable Table 16-5. IEN1 Register 83 4337K–USB–04/08 IEN1 - Interrupt Enable Register (B1h) 7 Bit Number 7 6 EUSB Bit Mnemonic Description Reserved USB Interrupt Enable bit 6 EUSB Cleared to disable USB interrupt. Set to enable USB interrupt. Reserved Reserved Reserved SPI interrupt Enable bit Cleared to disable SPI interrupt. Set to enable SPI interrupt. TWI interrupt Enable bit Cleared to disable TWI interrupt. Set to enable TWI interrupt. Keyboard interrupt Enable bit Cleared to disable keyboard interrupt. Set to enable keyboard interrupt. 5 4 3 2 ESPI 1 ETWI 0 EKB 5 4 3 - 2 ESPI 1 ETWI 0 EKB 84 AT89C5130A/31A-M 4337K–USB–04/08 AT89C5130A/31A-M Reset Value = X0XX X000b Not bit addressable Table 16-6. IPL1 Register IPL1 - Interrupt Priority Register (B2h) 7 Bit Number 7 6 PUSBL Bit Mnemonic Description Reserved The value read from this bit is indeterminate. Do not set this bit. USB Interrupt Priority bit Refer to PUSBH for priority level. Reserved The value read from this bit is indeterminate. Do not set this bit. Reserved The value read from this bit is indeterminate. Do not set this bit. Reserved The value read from this bit is indeterminate. Do not set this bit. SPI Interrupt Priority bit Refer to PSPIH for priority level. TWI Interrupt Priority bit Refer to PTWIH for priority level. Keyboard Interrupt Priority bit Refer to PKBH for priority level. 5 4 3 2 PSPIL 1 PTWIL 0 PKBDL 6 PUSBL 5 - 4 - 3 - 2 PSPIL 1 PTWIL 0 PKBL Reset Value = X0XX X000b Not bit addressable 85 4337K–USB–04/08 Table 16-7. IPH1 Register IPH1 - Interrupt Priority High Register (B3h) 7 Bit Number 7 6 PUSBH Bit Mnemonic Description Reserved The value read from this bit is indeterminate. Do not set this bit. USB Interrupt Priority High bit PUSBH PUSBL Priority Level 0 0 Lowest 0 1 1 0 1 1 Highest Reserved The value read from this bit is indeterminate. Do not set this bit. Reserved The value read from this bit is indeterminate. Do not set this bit. Reserved The value read from this bit is indeterminate. Do not set this bit. SPI Interrupt Priority High bit PSPIH PSPIL Priority Level 0 0 Lowest 0 1 1 0 1 1 Highest TWI Interrupt Priority High bit PTWIH PTWIL Priority Level 0 0 Lowest 0 1 1 0 1 1 Highest Keyboard Interrupt Priority High bit PKBH PKBL Priority Level 0 0 Lowest 0 1 1 0 1 1 Highest 5 4 3 2 PSPIH 1 PTWIH 0 PKBH 6 PUSBH 5 - 4 - 3 - 2 PSPIH 1 PTWIH 0 PKBH Reset Value = X0XX X000b Not bit addressable 86 AT89C5130A/31A-M 4337K–USB–04/08 AT89C5130A/31A-M 16.3 Interrupt Sources and Vector Addresses Table 16-8. Number 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Vector Table Polling Priority 0 1 2 3 4 6 7 5 8 9 10 11 12 13 14 15 USB UEPINT + USBINT Interrupt Source Reset INT0 Timer 0 INT1 Timer 1 UART Timer 2 PCA Keyboard TWI SPI IE0 TF0 IE1 IF1 RI+TI TF2+EXF2 CF + CCFn (n = 0-4) KBDIT TWIIT SPIIT Interrupt Request Vector Address 0000h 0003h 000Bh 0013h 001Bh 0023h 002Bh 0033h 003Bh 0043h 004Bh 0053h 005Bh 0063h 006Bh 0073h 87 4337K–USB–04/08 17. Keyboard Interface 17.1 Introduction The AT89C5130A/31A-M implements a keyboard interface allowing the connection of a 8 x n matrix keyboard. It is based on 8 inputs with programmable interrupt capability on both high or low level. These inputs are available as an alternate function of P1 and allow to exit from idle and power down modes. 17.2 Description The keyboard interface communicates with the C51 core through 3 special function registers: KBLS, the Keyboard Level Selection register (Table 17-3), KBE, The Keyboard interrupt Enable register (Table 17-2), and KBF, the Keyboard Flag register (Table 17-1). 17.2.1 Interrupt The keyboard inputs are considered as 8 independent interrupt sources sharing the same interrupt vector. An interrupt enable bit (KBD in IE1) allows global enable or disable of the keyboard interrupt (see Figure 17-1). As detailed in Figure 17-2 each keyboard input has the capability to detect a programmable level according to KBLS.x bit value. Level detection is then reported in interrupt flags KBF.x that can be masked by software using KBE.x bits. This structure allow keyboard arrangement from 1 by n to 8 by n matrix and allow usage of P1 inputs for other purpose. Figure 17-1. Keyboard Interface Block Diagram P1.0 P1.1 P1.2 P1.3 P1.4 P1.5 P1.6 P1.7 Input Circuitry Input Circuitry Input Circuitry Input Circuitry KBDIT Input Circuitry Input Circuitry Input Circuitry Input Circuitry KBD IE1.0 Keyboard Interface Interrupt Request Figure 17-2. Keyboard Input Circuitry Vcc 0 P1:x 1 Internal Pull-up KBF.x KBE.x KBLS.x 88 AT89C5130A/31A-M 4337K–USB–04/08 AT89C5130A/31A-M 17.2.2 Power Reduction Mode P1 inputs allow exit from idle and power down modes as detailed in section “Power-down Mode”. 17.3 Registers Table 17-1. KBF Register KBF - Keyboard Flag Register (9Eh) 7 KBF7 6 KBF6 Bit Mnemonic 5 KBF5 4 KBF4 3 KBF3 2 KBF2 1 KBF1 0 KBF0 Bit Number Description Keyboard line 7 flag Set by hardware when the Port line 7 detects a programmed level. It generates a Keyboard interrupt request if the KBKBIE.7 bit in KBIE register is set. Cleared by hardware when reading KBF SFR by software. Keyboard line 6 flag Set by hardware when the Port line 6 detects a programmed level. It generates a Keyboard interrupt request if the KBIE.6 bit in KBIE register is set. Cleared by hardware when reading KBF SFR by software. Keyboard line 5 flag Set by hardware when the Port line 5 detects a programmed level. It generates a Keyboard interrupt request if the KBIE.5 bit in KBIE register is set. Cleared by hardware when reading KBF SFR by software. Keyboard line 4 flag Set by hardware when the Port line 4 detects a programmed level. It generates a Keyboard interrupt request if the KBIE.4 bit in KBIE register is set. Cleared by hardware when reading KBF SFR by software. Keyboard line 3 flag Set by hardware when the Port line 3 detects a programmed level. It generates a Keyboard interrupt request if the KBIE.3 bit in KBIE register is set. Cleared by hardware when reading KBF SFR by software. Keyboard line 2 flag Set by hardware when the Port line 2 detects a programmed level. It generates a Keyboard interrupt request if the KBIE.2 bit in KBIE register is set. Cleared by hardware when reading KBF SFR by software. Keyboard line 1 flag Set by hardware when the Port line 1 detects a programmed level. It generates a Keyboard interrupt request if the KBIE.1 bit in KBIE register is set. Cleared by hardware when reading KBF SFR by software. Keyboard line 0 flag Set by hardware when the Port line 0 detects a programmed level. It generates a Keyboard interrupt request if the KBIE.0 bit in KBIE register is set. Cleared by hardware when reading KBF SFR by software. 7 KBF7 6 KBF6 5 KBF5 4 KBF4 3 KBF3 2 KBF2 1 KBF1 0 KBF0 Reset Value = 0000 0000b 89 4337K–USB–04/08 Table 17-2. KBE Register KBE - Keyboard Input Enable Register (9Dh) 7 KBE7 Bit Number 6 KBE6 Bit Mnemonic 5 KBE5 4 KBE4 3 KBE3 2 KBE2 1 KBE1 0 KBE0 Description Keyboard line 7 Enable bit Cleared to enable standard I/O pin. Set to enable KBF.7 bit in KBF register to generate an interrupt request. Keyboard line 6 Enable bit Cleared to enable standard I/O pin. Set to enable KBF.6 bit in KBF register to generate an interrupt request. Keyboard line 5 Enable bit Cleared to enable standard I/O pin. Set to enable KBF.5 bit in KBF register to generate an interrupt request. Keyboard line 4 Enable bit Cleared to enable standard I/O pin. Set to enable KBF.4 bit in KBF register to generate an interrupt request. Keyboard line 3 Enable bit Cleared to enable standard I/O pin. Set to enable KBF.3 bit in KBF register to generate an interrupt request. Keyboard line 2 Enable bit Cleared to enable standard I/O pin. Set to enable KBF.2 bit in KBF register to generate an interrupt request. Keyboard line 1 Enable bit Cleared to enable standard I/O pin. Set to enable KBF.1 bit in KBF register to generate an interrupt request. Keyboard line 0 Enable bit Cleared to enable standard I/O pin. Set to enable KBF.0 bit in KBF register to generate an interrupt request. 7 KBE7 6 KBE6 5 KBE5 4 KBE4 3 KBE3 2 KBE2 1 KBE1 0 KBE0 Reset Value = 0000 0000b 90 AT89C5130A/31A-M 4337K–USB–04/08 AT89C5130A/31A-M Table 17-3. KBLS Register KBLS-Keyboard Level Selector Register (9Ch) 7 KBLS7 6 KBLS6 Bit Mnemonic 5 KBLS5 4 KBLS4 3 KBLS3 2 KBLS2 1 KBLS1 0 KBLS0 Bit Number Description Keyboard line 7 Level Selection bit Cleared to enable a low level detection on Port line 7. Set to enable a high level detection on Port line 7. Keyboard line 6 Level Selection bit Cleared to enable a low level detection on Port line 6. Set to enable a high level detection on Port line 6. Keyboard line 5 Level Selection bit Cleared to enable a low level detection on Port line 5. Set to enable a high level detection on Port line 5. Keyboard line 4 Level Selection bit Cleared to enable a low level detection on Port line 4. Set to enable a high level detection on Port line 4. Keyboard line 3 Level Selection bit Cleared to enable a low level detection on Port line 3. Set to enable a high level detection on Port line 3. Keyboard line 2 Level Selection bit Cleared to enable a low level detection on Port line 2. Set to enable a high level detection on Port line 2. Keyboard line 1 Level Selection bit Cleared to enable a low level detection on Port line 1. Set to enable a high level detection on Port line 1. Keyboard line 0 Level Selection bit Cleared to enable a low level detection on Port line 0. Set to enable a high level detection on Port line 0. 7 KBLS7 6 KBLS6 5 KBLS5 4 KBLS4 3 KBLS3 2 KBLS2 1 KBLS1 0 KBLS0 Reset Value = 0000 0000b 91 4337K–USB–04/08 18. Programmable LED AT89C5130A/31A-M have up to 4 programmable LED current sources, configured by the register LEDCON. Table 18-1. LEDCON Register LEDCON (S:F1h) LED Control Register 7 LED3 Bit Mnemonic 6 5 LED2 4 3 LED1 2 1 LED0 0 Bit Number Description Port 0 0 1 1 Port 0 0 1 1 Port/ 0 0 1 1 Port/ 0 0 1 1 LED3 0 1 0 1 /LED2 0 1 0 1 LED1 0 1 0 1 LED0 0 1 0 1 Configuration Standard C51 Port 2 mA current source when P3.7 is low 4 mA current source when P3.7 is low 10 mA current source when P3.7 is low Configuration Standard C51 Port 2 mA current source when P3.6 is low 4 mA current source when P3.6 is low 10 mA current source when P3.6 is low Configuration Standard C51 Port 2 mA current source when P3.5 is low 4 mA current source when P3.5 is low 10 mA current source when P3.5 is low Configuration Standard C51 Port 2 mA current source when P3.3 is low 4 mA current source when P3.3 is low 10 mA current source when P3.3 is low 7:6 LED3 5:4 LED2 3:2 LED1 1:0 LED0 Reset Value = 00h 92 AT89C5130A/31A-M 4337K–USB–04/08 AT89C5130A/31A-M 19. Serial Peripheral Interface (SPI) The Serial Peripheral Interface module (SPI) allows full-duplex, synchronous, serial communication between the MCU and peripheral devices, including other MCUs. 19.1 Features Features of the SPI module include the following: • Full-duplex, three-wire synchronous transfers • Master or Slave operation • Eight programmable Master clock rates • Serial clock with programmable polarity and phase • Master mode fault error flag with MCU interrupt capability • Write collision flag protection 19.2 Signal Description Figure 19-1 shows a typical SPI bus configuration using one Master controller and many Slave peripherals. The bus is made of three wires connecting all the devices: Figure 19-1. SPI Master/Slaves Interconnection MISO MOSI SCK SS Slave 1 MISO MOSI SCK SS VDD Master 0 1 2 3 PORT MISO MOSI SCK SS Slave 4 Slave 3 MISO MOSI SCK SS Slave 2 The Master device selects the individual Slave devices by using four pins of a parallel port to control the four SS pins of the Slave devices. 19.2.1 Master Output Slave Input (MOSI) This 1-bit signal is directly connected between the Master Device and a Slave Device. The MOSI line is used to transfer data in series from the Master to the Slave. Therefore, it is an output signal from the Master, and an input signal to a Slave. A byte (8-bit word) is transmitted most significant bit (MSB) first, least significant bit (LSB) last. Master Input Slave Output (MISO) This 1-bit signal is directly connected between the Slave Device and a Master Device. The MISO line is used to transfer data in series from the Slave to the Master. Therefore, it is an output signal from the Slave, and an input signal to the Master. A byte (8-bit word) is transmitted most significant bit (MSB) first, least significant bit (LSB) last. 19.2.2 MISO MOSI SCK SS 93 4337K–USB–04/08 19.2.3 SPI Serial Clock (SCK) This signal is used to synchronize the data movement both in and out the devices through their MOSI and MISO lines. It is driven by the Master for eight clock cycles which allows to exchange one byte on the serial lines. Slave Select (SS) Each Slave peripheral is selected by one Slave Select pin (SS). This signal must stay low for any message for a Slave. It is obvious that only one Master (SS high level) can drive the network. The Master may select each Slave device by software through port pins (Figure 19-1). To prevent bus conflicts on the MISO line, only one slave should be selected at a time by the Master for a transmission. In a Master configuration, the SS line can be used in conjunction with the MODF flag in the SPI Status register (SPSTA) to prevent multiple masters from driving MOSI and SCK (see Section “Error Conditions”, page 98). A high level on the SS pin puts the MISO line of a Slave SPI in a high-impedance state. The SS pin could be used as a general-purpose if the following conditions are met: • The device is configured as a Master and the SSDIS control bit in SPCON is set. This kind of configuration can be found when only one Master is driving the network and there is no way that the SS pin could be pulled low. Therefore, the MODF flag in the SPSTA will never be set(1). • The Device is configured as a Slave with CPHA and SSDIS control bits set(2) This kind of configuration can happen when the system comprises one Master and one Slave only. Therefore, the device should always be selected and there is no reason that the Master uses the SS pin to select the communicating Slave device. Notes: 1. Clearing SSDIS control bit does not clear MODF. 2. Special care should be taken not to set SSDIS control bit when CPHA =’0’ because in this mode, the SS is used to start the transmission. 19.2.4 19.2.5 Baud Rate In Master mode, the baud rate can be selected from a baud rate generator which is controlled by three bits in the SPCON register: SPR2, SPR1 and SPR0. The Master clock is chosen from one of seven clock rates resulting from the division of the internal clock by 4, 8, 16, 32, 64 or 128. Table 19-1 gives the different clock rates selected by SPR2:SPR1:SPR0: Table 19-1. SPR2 0 0 0 0 1 1 1 SPI Master Baud Rate Selection SPR1 0 0 1 1 0 0 1 SPR0 0 1 0 1 0 1 0 Clock Rate Don’t Use FCLK PERIPH/4 FCLK PERIPH/8 FCLK PERIPH/16 FCLK PERIPH/32 FCLK PERIPH/64 FCLK PERIPH/128 Baud Rate Divisor (BD) No BRG 4 8 16 32 64 128 94 AT89C5130A/31A-M 4337K–USB–04/08 AT89C5130A/31A-M SPR2 1 SPR1 1 SPR0 1 Clock Rate Don’t Use Baud Rate Divisor (BD) No BRG 19.3 Functional Description Figure 19-2 shows a detailed structure of the SPI module. Figure 19-2. SPI Module Block Diagram Internal Bus SPDAT FCLK PERIPH Shift Register 7 6 5 4 3 2 1 0 Clock Divider /4 /8 /16 /32 /64 /128 Receive Data Register Pin Control Logic MOSI MISO Clock Logic Clock Select M S SCK SS SPR2 SPEN SSDIS MSTR CPOL CPHA SPR1 SPR0 SPCON SPI Control 8-bit bus 1-bit signal SPI Interrupt Request SPSTA SPIF WCOL SSERR MODF - 19.3.1 Operating Modes The Serial Peripheral Interface can be configured as one of the two modes: Master mode or Slave mode. The configuration and initialization of the SPI module is made through one register: • The Serial Peripheral CONtrol register (SPCON) Once the SPI is configured, the data exchange is made using: • SPCON • The Serial Peripheral STAtus register (SPSTA) • The Serial Peripheral DATa register (SPDAT) During an SPI transmission, data is simultaneously transmitted (shifted out serially) and received (shifted in serially). A serial clock line (SCK) synchronizes shifting and sampling on the two serial data lines (MOSI and MISO). A Slave Select line (SS) allows individual selection of a Slave SPI device; Slave devices that are not selected do not interfere with SPI bus activities. 95 4337K–USB–04/08 When the Master device transmits data to the Slave device via the MOSI line, the Slave device responds by sending data to the Master device via the MISO line. This implies full-duplex transmission with both data out and data in synchronized with the same clock (Figure 19-3). Figure 19-3. Full-duplex Master/Slave Interconnection 8-bit Shift Register MISO MOSI SPI Clock Generator SCK SS VDD MISO MOSI SCK SS VSS 8-bit Shift Register Master MCU Slave MCU 19.3.1.1 Master Mode The SPI operates in Master mode when the Master bit, MSTR (1), in the SPCON register is set. Only one Master SPI device can initiate transmissions. Software begins the transmission from a Master SPI module by writing to the Serial Peripheral Data Register (SPDAT). If the shift register is empty, the byte is immediately transferred to the shift register. The byte begins shifting out on MOSI pin under the control of the serial clock, SCK. Simultaneously, another byte shifts in from the Slave on the Master’s MISO pin. The transmission ends when the Serial Peripheral transfer data flag, SPIF, in SPSTA becomes set. At the same time that SPIF becomes set, the received byte from the Slave is transferred to the receive data register in SPDAT. Software clears SPIF by reading the Serial Peripheral Status register (SPSTA) with the SPIF bit set, and then reading the SPDAT. Slave Mode The SPI operates in Slave mode when the Master bit, MSTR ( 2) , in the SPCON register is cleared. Before a data transmission occurs, the Slave Select pin, SS, of the Slave device must be set to’0’. SS must remain low until the transmission is complete. In a Slave SPI module, data enters the shift register under the control of the SCK from the Master SPI module. After a byte enters the shift register, it is immediately transferred to the receive data register in SPDAT, and the SPIF bit is set. To prevent an overflow condition, Slave software must then read the SPDAT before another byte enters the shift register (3). A Slave SPI must complete the write to the SPDAT (shift register) at least one bus cycle before the Master SPI starts a transmission. If the write to the data register is late, the SPI transmits the data already in the shift register from the previous transmission. 19.3.1.2 19.3.2 Transmission Formats Software can select any of four combinations of serial clock (SCK) phase and polarity using two bits in the SPCON: the Clock POLarity (CPOL (4)) and the Clock PHAse (CPHA4). CPOL defines the default SCK line level in idle state. It has no significant effect on the transmission format. CPHA defines the edges on which the input data are sampled and the edges on which the 1. 2. 3. 4. The SPI module should be configured as a Master before it is enabled (SPEN set). Also the Master SPI should be configured before the Slave SPI. The SPI module should be configured as a Slave before it is enabled (SPEN set). The maximum frequency of the SCK for an SPI configured as a Slave is FCLK PERIPH/2. Before writing to the CPOL and CPHA bits, the SPI should be disabled (SPEN =’0’). 96 AT89C5130A/31A-M 4337K–USB–04/08 AT89C5130A/31A-M output data are shifted (Figure 19-4 and Figure 19-5). The clock phase and polarity should be identical for the Master SPI device and the communicating Slave device. Figure 19-4. Data Transmission Format (CPHA = 0) SCK cycle number SPEN (internal) 1 2 3 4 5 6 7 8 SCK (CPOL = 0) SCK (CPOL = 1) MOSI (from Master) MISO (from Slave) SS (to Slave) Capture point MSB MSB bit6 bit6 bit5 bit5 bit4 bit4 bit3 bit3 bit2 bit2 bit1 bit1 LSB LSB Figure 19-5. Data Transmission Format (CPHA = 1) SCK cycle number SPEN (internal) SCK (CPOL = 0) SCK (CPOL = 1) MOSI (from Master) MISO (from Slave) SS (to Slave) Capture point MSB MSB bit6 bit6 bit5 bit5 bit4 bit4 bit3 bit3 bit2 bit2 bit1 bit1 LSB LSB 1 2 3 4 5 6 7 8 Figure 19-6. CPHA/SS Timing MISO/MOSI Master SS Slave SS (CPHA = 0) Slave SS (CPHA = 1) Byte 1 Byte 2 Byte 3 As shown in Figure 19-5, the first SCK edge is the MSB capture strobe. Therefore the Slave must begin driving its data before the first SCK edge, and a falling edge on the SS pin is used to start the transmission. The SS pin must be toggled high and then low between each byte transmitted (Figure 19-2). Figure 19-6 shows an SPI transmission in which CPHA is’1’. In this case, the Master begins driving its MOSI pin on the first SCK edge. Therefore the Slave uses the first SCK edge as a start transmission signal. The SS pin can remain low between transmissions (Figure 19-1). This format may be preferable in systems having only one Master and only one Slave driving the MISO data line. 97 4337K–USB–04/08 19.3.3 Error Conditions The following flags in the SPSTA signal SPI error conditions: Mode Fault (MODF) Mode Fault error in Master mode SPI indicates that the level on the Slave Select (SS) pin is inconsistent with the actual mode of the device. MODF is set to warn that there may have a multi-master conflict for system control. In this case, the SPI system is affected in the following ways: • An SPI receiver/error CPU interrupt request is generated, • The SPEN bit in SPCON is cleared. This disable the SPI, • The MSTR bit in SPCON is cleared When SS DISable (SSDIS) bit in the SPCON register is cleared, the MODF flag is set when the SS signal becomes “0”. However, as stated before, for a system with one Master, if the SS pin of the Master device is pulled low, there is no way that another Master attempt to drive the network. In this case, to prevent the MODF flag from being set, software can set the SSDIS bit in the SPCON register and therefore making the SS pin as a general-purpose I/O pin. Clearing the MODF bit is accomplished by a read of SPSTA register with MODF bit set, followed by a write to the SPCON register. SPEN Control bit may be restored to its original set state after the MODF bit has been cleared. 19.3.3.1 19.3.3.2 Write Collision (WCOL) A Write Collision (WCOL) flag in the SPSTA is set when a write to the SPDAT register is done during a transmit sequence. WCOL does not cause an interruption, and the transfer continues uninterrupted. Clearing the WCOL bit is done through a software sequence of an access to SPSTA and an access to SPDAT. 19.3.3.3 Overrun Condition An overrun condition occurs when the Master device tries to send several data bytes and the Slave devise has not cleared the SPIF bit issuing from the previous data byte transmitted. In this case, the receiver buffer contains the byte sent after the SPIF bit was last cleared. A read of the SPDAT returns this byte. All others bytes are lost. This condition is not detected by the SPI peripheral. 19.3.4 Interrupts Two SPI status flags can generate a CPU interrupt requests: Table 19-2. Flag SPI Interrupts Request SPI Transmitter Interrupt request SPI Receiver/Error Interrupt Request (if SSDIS = “0”) SPIF (SP Data Transfer) MODF (Mode Fault) Serial Peripheral data transfer flag, SPIF: This bit is set by hardware when a transfer has been completed. SPIF bit generates transmitter CPU interrupt requests. 98 AT89C5130A/31A-M 4337K–USB–04/08 AT89C5130A/31A-M Mode Fault flag, MODF: This bit becomes set to indicate that the level on the SS is inconsistent with the mode of the SPI. MODF with SSDIS reset, generates receiver/error CPU interrupt requests. Figure 19-7 gives a logical view of the above statements. Figure 19-7. SPI Interrupt Requests Generation SPIF SPI Transmitter CPU Interrupt Request SPI Receiver/Error CPU Interrupt Request SSDIS SPI CPU Interrupt Request MODF 19.3.5 Registers There are three registers in the module that provide control, status and data storage functions. These registers are describes in the following paragraphs. 19.3.5.1 Serial Peripheral Control Register (SPCON) • The Serial Peripheral Control Register does the following: – Selects one of the Master clock rates – Configure the SPI module as Master or Slave – Selects serial clock polarity and phase – Enables the SPI module – Frees the SS pin for a general-purpose Table 19-3 describes this register and explains the use of each bit. Table 19-3. 7 SPR2 Bit Number 7 SPCON Register 6 SPEN 5 SSDIS 4 MSTR 3 CPOL 2 CPHA 1 SPR1 0 SPR0 Bit Mnemonic SPR2 Description Serial Peripheral Rate 2 Bit with SPR1 and SPR0 define the clock rate. Serial Peripheral Enable 6 SPEN Cleared to disable the SPI interface. Set to enable the SPI interface. SS Disable 5 SSDIS Cleared to enable SS in both Master and Slave modes. Set to disable SS in both Master and Slave modes. In Slave mode, this bit has no effect if CPHA = “0”. Serial Peripheral Master 4 MSTR Cleared to configure the SPI as a Slave. Set to configure the SPI as a Master. Clock Polarity 3 CPOL Cleared to have the SCK set to “0” in idle state. Set to have the SCK set to “1” in idle state. 99 4337K–USB–04/08 Bit Number Bit Mnemonic Description Clock Phase 2 CPHA Cleared to have the data sampled when the SCK leaves the idle state (see CPOL). Set to have the data sampled when the SCK returns to idle state (see CPOL). SPR2 SPR1 SPR0 Serial Peripheral Rate 1 SPR1 000Reserved 00 1FCLK PERIPH/4 010 FCLK PERIPH/8 011FCLK PERIPH/16 100FCLK PERIPH/32 0 SPR0 10 1FCLK PERIPH/64 110FCLK PERIPH/128 1 11Reserved Reset Value = 0001 0100b Not bit addressable 19.3.5.2 Serial Peripheral Status Register (SPSTA) The Serial Peripheral Status Register contains flags to signal the following conditions: • Data transfer complete • Write collision • Inconsistent logic level on SS pin (mode fault error) Table 19-4 describes the SPSTA register and explains the use of every bit in the register. Table 19-4. SPSTA Register SPSTA - Serial Peripheral Status and Control register (0C4H) 7 SPIF 6 WCOL Bit Mnemonic 5 SSERR 4 MODF 3 2 1 0 - Bit Number Description Serial Peripheral data transfer flag 7 SPIF Cleared by hardware to indicate data transfer is in progress or has been approved by a clearing sequence. Set by hardware to indicate that the data transfer has been completed. Write Collision flag 6 WCOL Cleared by hardware to indicate that no collision has occurred or has been approved by a clearing sequence. Set by hardware to indicate that a collision has been detected. Synchronous Serial Slave Error flag 5 SSERR Set by hardware when SS is deasserted before the end of a received data. Cleared by disabling the SPI (clearing SPEN bit in SPCON). 100 AT89C5130A/31A-M 4337K–USB–04/08 AT89C5130A/31A-M Bit Number Bit Mnemonic Description Mode Fault 4 MODF Cleared by hardware to indicate that the SS pin is at appropriate logic level, or has been approved by a clearing sequence. Set by hardware to indicate that the SS pin is at inappropriate logic level. 3 Reserved The value read from this bit is indeterminate. Do not set this bit Reserved The value read from this bit is indeterminate. Do not set this bit Reserved The value read from this bit is indeterminate. Do not set this bit. Reserved The value read from this bit is indeterminate. Do not set this bit. 2 - 1 - 0 - Reset Value = 00X0 XXXXb Not Bit addressable 19.3.5.3 Serial Peripheral Data Register (SPDAT) The Serial Peripheral Data Register (Table 19-5) is a read/write buffer for the receive data register. A write to SPDAT places data directly into the shift register. No transmit buffer is available in this model. A Read of the SPDAT returns the value located in the receive buffer and not the content of the shift register. Table 19-5. SPDAT Register SPDAT - Serial Peripheral Data Register (0C5H) 7 R7 6 R6 5 R5 4 R4 3 R3 2 R2 1 R1 0 R0 Reset Value = Indeterminate R7:R0: Receive data bits SPCON, SPSTA and SPDAT registers may be read and written at any time while there is no ongoing exchange. However, special care should be taken when writing to them while a transmission is on-going: • Do not change SPR2, SPR1 and SPR0 • Do not change CPHA and CPOL • Do not change MSTR • Clearing SPEN would immediately disable the peripheral • Writing to the SPDAT will cause an overflow 101 4337K–USB–04/08 20. Two Wire Interface (TWI) This section describes the 2-wire interface. The 2-wire bus is a bi-directional 2-wire serial communication standard. It is designed primarily for simple but efficient integrated circuit (IC) control. The system is comprised of two lines, SCL (Serial Clock) and SDA (Serial Data) that carry information between the ICs connected to them. The serial data transfer is limited to 400 Kbit/s in standard mode. Various communication configuration can be designed using this bus. Figure 20-1 shows a typical 2-wire bus configuration. All the devices connected to the bus can be master and slave. Figure 20-1. 2-wire Bus Configuration device1 device2 device3 ... deviceN SCL SDA 102 AT89C5130A/31A-M 4337K–USB–04/08 AT89C5130A/31A-M Figure 20-2. Block Diagram 8 SSADR Address Register Input Filter SDA Output Stage Comparator SSDAT Shift Register ACK 8 Input Filter SCL Output Stage Timer 1 overflow SSCON Arbitration & Sink Logic Timing & Control logic FCLK PERIPH/4 Serial clock generator Interrupt Control Register 7 Status Bits Status Decoder SSCS Status Register 8 Internal Bus 103 4337K–USB–04/08 20.1 Description The CPU interfaces to the 2-wire logic via the following four 8-bit special function registers: the Synchronous Serial Control register (SSCON; Table 20-10), the Synchronous Serial Data register (SSDAT; Table 20-11), the Synchronous Serial Control and Status register (SSCS; Table 2012) and the Synchronous Serial Address register (SSADR Table 20-13). SSCON is used to enable the TWI interface, to program the bit rate (see Table 20-3), to enable slave modes, to acknowledge or not a received data, to send a START or a STOP condition on the 2-wire bus, and to acknowledge a serial interrupt. A hardware reset disables the TWI module. SSCS contains a status code which reflects the status of the 2-wire logic and the 2-wire bus. The three least significant bits are always zero. The five most significant bits contains the status code. There are 26 possible status codes. When SSCS contains F8h, no relevant state information is available and no serial interrupt is requested. A valid status code is available in SSCS one machine cycle after SI is set by hardware and is still present one machine cycle after SI has been reset by software. to Table 20-9. give the status for the master modes and miscellaneous states. SSDAT contains a byte of serial data to be transmitted or a byte which has just been received. It is addressable while it is not in process of shifting a byte. This occurs when 2-wire logic is in a defined state and the serial interrupt flag is set. Data in SSDAT remains stable as long as SI is set. While data is being shifted out, data on the bus is simultaneously shifted in; SSDAT always contains the last byte present on the bus. SSADR may be loaded with the 7-bit slave address (7 most significant bits) to which the TWI module will respond when programmed as a slave transmitter or receiver. The LSB is used to enable general call address (00h) recognition. Figure 20-3 shows how a data transfer is accomplished on the 2-wire bus. Figure 20-3. Complete Data Transfer on 2-wire Bus SDA MSB acknowledgement signal from receiver acknowledgement signal from receiver 2 3-8 9 ACK SCL S start condition 1 2 7 8 9 ACK 1 clock line held low while interrupts are serviced P stop condition The four operating modes are: • Master Transmitter • Master Receiver • Slave transmitter • Slave receiver Data transfer in each mode of operation is shown in Table to Table 20-9 and Figure 20-4. to Figure 20-7.. These figures contain the following abbreviations: S : START condition 104 AT89C5130A/31A-M 4337K–USB–04/08 AT89C5130A/31A-M R W A: : Read bit (high level at SDA) : Write bit (low level at SDA) Acknowledge bit (low level at SDA) A: Not acknowledge bit (high level at SDA) Data: 8-bit data byte P : STOP condition In Figure 20-4 to Figure 20-7, circles are used to indicate when the serial interrupt flag is set. The numbers in the circles show the status code held in SSCS. At these points, a service routine must be executed to continue or complete the serial transfer. These service routines are not critical since the serial transfer is suspended until the serial interrupt flag is cleared by software. When the serial interrupt routine is entered, the status code in SSCS is used to branch to the appropriate service routine. For each status code, the required software action and details of the following serial transfer are given in Table to Table 20-9. 20.1.1 Master Transmitter Mode In the master transmitter mode, a number of data bytes are transmitted to a slave receiver (Figure 20-4). Before the master transmitter mode can be entered, SSCON must be initialised as follows: Table 20-1. CR2 bit rate SSCON Initialization SSIE 1 STA 0 STO 0 SI 0 AA X CR1 bit rate CR0 bit rate CR0, CR1 and CR2 define the internal serial bit rate if external bit rate generator is not used. SSIE must be set to enable TWI. STA, STO and SI must be cleared. The master transmitter mode may now be entered by setting the STA bit. The 2-wire logic will now test the 2-wire bus and generate a START condition as soon as the bus becomes free. When a START condition is transmitted, the serial interrupt flag (SI bit in SSCON) is set, and the status code in SSCS will be 08h. This status must be used to vector to an interrupt routine that loads SSDAT with the slave address and the data direction bit (SLA+W). When the slave address and the direction bit have been transmitted and an acknowledgement bit has been received, SI is set again and a number of status code in SSCS are possible. There are 18h, 20h or 38h for the master mode and also 68h, 78h or B0h if the slave mode was enabled (AA=logic 1). The appropriate action to be taken for each of these status code is detailed in Table . This scheme is repeated until a STOP condition is transmitted. SSIE, CR2, CR1 and CR0 are not affected by the serial transfer and are referred to Table 7 to Table 11. After a repeated START condition (state 10h) the TWI module may switch to the master receiver mode by loading SSDAT with SLA+R. 20.1.2 Master Receiver Mode In the master receiver mode, a number of data bytes are received from a slave transmitter (Figure 20-5). The transfer is initialized as in the master transmitter mode. When the START condition has been transmitted, the interrupt routine must load SSDAT with the 7-bit slave 105 4337K–USB–04/08 address and the data direction bit (SLA+R). The serial interrupt flag SI must then be cleared before the serial transfer can continue. When the slave address and the direction bit have been transmitted and an acknowledgement bit has been received, the serial interrupt flag is set again and a number of status code in SSCS are possible. There are 40h, 48h or 38h for the master mode and also 68h, 78h or B0h if the slave mode was enabled (AA=logic 1). The appropriate action to be taken for each of these status code is detailed in Table . This scheme is repeated until a STOP condition is transmitted. SSIE, CR2, CR1 and CR0 are not affected by the serial transfer and are referred to Table 7 to Table 11. After a repeated START condition (state 10h) the TWI module may switch to the master transmitter mode by loading SSDAT with SLA+W. 20.1.3 Slave Receiver Mode In the slave receiver mode, a number of data bytes are received from a master transmitter (Figure 20-6). To initiate the slave receiver mode, SSADR and SSCON must be loaded as follows: Table 20-2. A6 SSADR: Slave Receiver Mode Initialization A5 A4 A3 own slave address A2 A1 A0 GC The upper 7 bits are the address to which the TWI module will respond when addressed by a master. If the LSB (GC) is set the TWI module will respond to the general call address (00h); otherwise it ignores the general call address. Table 20-3. CR2 bit rate SSCON: Slave Receiver Mode Initialization SSIE 1 STA 0 STO 0 SI 0 AA 1 CR1 bit rate CR0 bit rate CR0, CR1 and CR2 have no effect in the slave mode. SSIE must be set to enable the TWI. The AA bit must be set to enable the own slave address or the general call address acknowledgement. STA, STO and SI must be cleared. When SSADR and SSCON have been initialised, the TWI module waits until it is addressed by its own slave address followed by the data direction bit which must be at logic 0 (W) for the TWI to operate in the slave receiver mode. After its own slave address and the W bit have been received, the serial interrupt flag is set and a valid status code can be read from SSCS. This status code is used to vector to an interrupt service routine.The appropriate action to be taken for each of these status code is detailed in Table . The slave receiver mode may also be entered if arbitration is lost while TWI is in the master mode (states 68h and 78h). If the AA bit is reset during a transfer, TWI module will return a not acknowledge (logic 1) to SDA after the next received data byte. While AA is reset, the TWI module does not respond to its own slave address. However, the 2-wire bus is still monitored and address recognition may be resume at any time by setting AA. This means that the AA bit may be used to temporarily isolate the module from the 2-wire bus. 106 AT89C5130A/31A-M 4337K–USB–04/08 AT89C5130A/31A-M 20.1.4 Slave Transmitter Mode In the slave transmitter mode, a number of data bytes are transmitted to a master receiver (Figure 20-7). Data transfer is initialized as in the slave receiver mode. When SSADR and SSCON have been initialized, the TWI module waits until it is addressed by its own slave address followed by the data direction bit which must be at logic 1 (R) for TWI to operate in the slave transmitter mode. After its own slave address and the R bit have been received, the serial interrupt flag is set and a valid status code can be read from SSCS. This status code is used to vector to an interrupt service routine. The appropriate action to be taken for each of these status code is detailed in Table . The slave transmitter mode may also be entered if arbitration is lost while the TWI module is in the master mode. If the AA bit is reset during a transfer, the TWI module will transmit the last byte of the transfer and enter state C0h or C8h. the TWI module is switched to the not addressed slave mode and will ignore the master receiver if it continues the transfer. Thus the master receiver receives all 1’s as serial data. While AA is reset, the TWI module does not respond to its own slave address. However, the 2-wire bus is still monitored and address recognition may be resume at any time by setting AA. This means that the AA bit may be used to temporarily isolate the TWI module from the 2-wire bus. 20.1.5 Miscellaneous States There are two SSCS codes that do not correspond to a define TWI hardware state (Table 20-9 ). These codes are discuss hereafter. Status F8h indicates that no relevant information is available because the serial interrupt flag is not set yet. This occurs between other states and when the TWI module is not involved in a serial transfer. Status 00h indicates that a bus error has occurred during a TWI serial transfer. A bus error is caused when a START or a STOP condition occurs at an illegal position in the format frame. Examples of such illegal positions happen during the serial transfer of an address byte, a data byte, or an acknowledge bit. When a bus error occurs, SI is set. To recover from a bus error, the STO flag must be set and SI must be cleared. This causes the TWI module to enter the not addressed slave mode and to clear the STO flag (no other bits in SSCON are affected). The SDA and SCL lines are released and no STOP condition is transmitted. 20.2 Notes The TWI module interfaces to the external 2-wire bus via two port pins: SCL (serial clock line) and SDA (serial data line). To avoid low level asserting on these lines when the TWI module is enabled, the output latches of SDA and SLC must be set to logic 1. Table 20-4. Bit Frequency Configuration Bit Frequency ( kHz) CR2 0 0 0 0 CR1 0 0 1 1 CR0 0 1 0 1 FOSCA= 12 MHz 47 53.5 62.5 75 FOSCA = 16 MHz 62.5 71.5 83 100 FOSCA divided by 256 224 192 160 107 4337K–USB–04/08 Bit Frequency ( kHz) CR2 1 1 1 CR1 0 0 1 CR0 0 1 0 FOSCA= 12 MHz 100 200 FOSCA = 16 MHz 133.3 266.6 FOSCA divided by Unused 120 60 Timer 1 in mode 2 can be used as TWI baudrate generator with the following formula: 96.(256-”Timer1 reload value”) 1 1 1 0.5