AT80SND2CMP3B

Features • MPEG I/II-Layer 3 Hardwired Decoder – Stand-alone MP3 Decoder – 48, 44.1, 32, 24, 22.05, 16 kHz Sampling Frequency – Separated Digital Volume Control on Left and Right Channels (Software Control using 31 Steps) – Bass, Medium, and Treble Control (31 Steps) – Bass Boost Sound Effect – Ancillary Data Extraction – CRC Error and MPEG Frame Synchronization Indicators 20-bit Stereo Audio DAC – 93 dB SNR playback stereo channel – 32 Ohm/ 20 mW stereo headset drivers – Stereo Line Level Input, Differential Mono Auxiliary Input Programmable Audio Output for Interfacing with External Audio System – PCM Format Compatible – I2S Format Compatible Mono Audio Power Amplifier – 440mW on 8 Ohms Load 8-bit MCU C51 Core Based (F MAX = 20 MHz) 2304 Bytes of Internal RAM 64K Bytes of Code Memory – AT89C51SND2C and 89SND2CMP3B: Flash (100K Erase/Write Cycles) – AT83SND2C and 83SND2CMP3B: ROM 4K Bytes of Boot Flash Memory (AT89C51SND2C and 89SND2CMP3B) – ISP: Download from USB (standard) or UART (option) USB Rev 1.1 Controller – Full Speed Data Transmission Built-in PLL – MP3 Audio Clocks – USB Clock MultiMedia Card ® Interface Compatibility Atmel DataFlash ® SPI Interface Compatibility IDE/ATAPI Interface 2 Channels 10-bit ADC 8 kHz (8-true bit) for AT8XSND2CMP3B – Battery Voltage Monitoring – Voice Recording Controller by Software Up to 32 Bits of General-purpose I/Os – 1 Interrupt Keyboard – SmartMedia ® Software Interface 2 Standard 16-bit Timers/Counters Hardware Watchdog Timer Standard Full Duplex UART with Baud Rate Generator Two Wire Master and Slave Modes Controller SPI Master and Slave Modes Controller Power Management – Power-on Reset – Software Programmable MCU Clock – Idle Mode, Power-down Mode Operating Conditions: – 2.7 to 3.6V – Power amplifier supply 3.2V to 5.5V – 37mA Typical Operating at 25°C playing music on earphone – Temperature Range: -40°C to +85 °C Packages – CTBGA100 • • • • • • • • • • • • • • • • • • • • Single-Chip Flash Microcontroller with MP3 Decoder with Full Audio Interface AT83SND2C AT89C51SND2C AT80SND2CMP3B AT83SND2CMP3B AT89SND2CMP3B • • 4341F–MP3–03/06 1. Description The AT8xC51SND2C has been developed for handling MP3 ringing tones in mobile phones and can replace sound generators while adding SD/MMC card reader, MP3 music decoding, and connection of the cell phone to a PC through USB. Cell phones can also be used as a thumb drive extending cell phone capabilities. The AT8xC51SND2C are fully integrated stand-alone hardwired MPEG I/II-Layer 3 decoder with a C51 microcontroller core handling data flow, MP3-player control, Stereo Audio DAC and Mono Audio Power Amplifier for speaker control. The AT89C51SND2C includes 64K Bytes of Flash memory and allows In-System Programming through an embedded 4K Bytes of Boot Flash memory. The AT83SND2C includes 64K Bytes of ROM memory. The AT8xC51SND2C include 2304 Bytes of RAM memory. The AT8xC51SND2C provides the necessary features for human interface like timers, keyboard port, serial or parallel interface (USB, TWI, SPI, IDE), I2S output, and all external memory inter face (NAND or NOR Flash, SmartMedia, MultiMedia, DataFlash cards). The AT8XSND2CMP3B provides also ADC input to the previous configuration. 89SND2CMP3B includes 64K Bytes of Flash memory. 83SND2CMP3B includes 64K Bytes of ROM memory. In the following of the document, AT8xC51SND2C refers to the generic product. When named explicitly, AT8XSND2CMP3B refers to the version with A/D converter. 2. Typical Applications • MP3-Player • PDA, Camera, Mobile Phone MP3 • Car Audio/Multimedia MP3 • Home Audio/Multimedia MP3 2 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B 3. Block Diagram Figure 3-1. AT8xC51SND2C / AT8XSND2CMP3B Block Diagram ISP ALE VDD VSS UVDD UVSS FILT X1 X2 RST 3 Clock and PLL Unit C51 (X2 Core) Interrupt Handler Unit INT0 INT1 3 (ADC is available on 8xSND2CMP3B only) 10-bit A to D Converter D+ DAREF AIN1:0 USB Controller I/OPorts IDE Interface MP3 Decoder Unit 8-Bit Internal Bus RAM 2304Bytes Flash ROM 64 KBytes Flash Boot 4 KBytes P0-P4 Keyboard Interface 3 3 KIN0 DOUT DCLK DSEL SCLK I2S/PCM Audio Interface UART and BRG TXD RXD Timers 0/1 Watchdog 3 3 4 4 4 4 T0 T1 HSR HSL AUXP AUXN LINEL LINER MONOP MONON Audio DAC SPI/DataFlash Controller SS MISO MOSI SCK SCL SDA TWI Controller MCLK PAINP PAINN HPP HPN Audio PA MMC Interface MDAT MCMD 3 Alternate function of Port 3 4 Alternate function of Port 4 3 4341F–MP3–03/06 4. Pin Description 4.1 Pinouts Figure 4-1. AT8xC51SND2C 100-pin BGA Package (no ADC) 10 NC 9 NC 8 P2.0/ A8 7 P4.1/ MOSI 6 VDD 5 VSS 4 NC 3 AUXP 2 AUXN 1 ALE A B C D E F G H J K VDD P2.2/ A10 P2.1/ A9 P4.0/ MISO P4.2/ SCK MONON MONOP P0.0/ AD0 KIN0 ISP/ NC P2.4/ A12 P2.3/ A11 P2.5/ A13 P4.3/ SS P0.6/ AD6 P0.4/ AD4 P0.3/ AD3 P0.2/ AD2 P0.1/ AD1 NC P2.6/ A14 P2.7/ A15 MCLK NC P0.7/ AD7 P0.5/ AD5 NC NC NC NC EA VSS VDD ESDVSS VDD SDA AUDVREF SCL HSL AUDVDD MCMD MDAT NC P3.2/ INT0 P3.1/ TXD VSS FILT PVDD HSR HSVDD RST AUDRST SCLK DSEL P3.4/ T0 P3.0/ RXD LINER LINEL PVSS HSVSS NC VSS DOUT DCLK P3.5/ T1 TST X1 X2 INGND AUDVSS VDD AUDVSS CBP LPHN P3.7/ RD P3.6/ WR VSS D- D+ AUDVCM PAINP PAINN HPP AUDVBAT HPN AUDVSS P3.3/ INT1 VDD UVDD UVSS Notes: 1. ISP pin is only available in AT89C51SND2C product. Do not connect this pin on AT83SND2C product. 2. NC is Do Not Connect. 4 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B 4.2 Figure 4-2. AT8XSND2CMP3B 100-pin BGA Package (with ADC) 10 P2.2/ A10 9 P2.1/ A9 8 P4.0/ MISO 7 ESDVSS 6 VDD 5 VSS 4 MONON 3 MONOP 2 P0.0/ AD0 1 ALE A B C D E F G H J K P2.3/ A11 P2.4/ A12 P2.0/ A8 P4.2/ SCK P0.7/ AD7 P0.5/ AD5 P0.3/ AD3 AUXP P0.1/ AD1 ISP/ NC VDD P2.5/ A13 P4.1/ MOSI P4.3/ SS P0.6/ AD6 P0.4/ AD4 P0.2/ AD2 AUXN KIN0 AUDVDD VSS P2.6/ A14 P2.7/ A15 SDA NC NC NC NC NC VDD VDD EA FILT CBP HSL AUDVREF AUDVCM HSR SCL HSVDD MCMD MCLK MDAT AIN1 ADCVDD P3.7/ RD TST LINEL PVDD HSVSS SCLK AUDRST RST AIN0 LPHN P3.4/ T0 P3.0/ RXD PVSS LINER VSS DCLK DOUT DSEL ADCV REFP ADCVSS P3.6/ WR P3.1/ TXD X2 INGND AUDVSS VSS PAINP PAINN ADCV REFN P3.3/ INT1 P3.5/ T1 P3.2/ INT0 X1 D+ UVDD ESDVSS AUDVSS HPP AUDVBAT AUDVBAT HPN AUDVSS D- VDD UVSS Notes: 1. ISP pin is only available in 89SND2CMP3B product. Do not connect this pin on 83SND2CMP3B product. 2. NC is Do Not Connect. 5 4341F–MP3–03/06 4.3 Signals All the AT8xC51SND2C and AT8XSND2CMP3B signals are detailed by functionality in Table 41 to Table 14. Table 4-1. Ports Signal Description Signal Name 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 polarized to VDD or VSS. Port 2 P2 is an 8-bit bidirectional I/O port with internal pull-ups. Alternate Function P0.7:0 I/O AD7:0 P2.7:0 I/O A15:8 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 MISO MOSI SCK SS P4.3:0 I/O Port 4 P4 is an 8-bit bidirectional I/O port with internal pull-ups. Table 4-2. Signal Name 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. X1 is the clock source for internal timing. 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 X2 unconnected. PLL Low Pass Filter input FILT receives the RC network of the PLL low pass filter. Alternate Function X1 I - X2 O - FILT I - Table 4-3. Signal Name Timer 0 and Timer 1 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. Alternate Function INT0 I External Interrupt 0 INT0 input sets IE0 in the TCON register. If bit IT0 in this register is set, bit IE0 is set by a falling edge on INT0#. If bit IT0 is cleared, bit IE0 is set by a low level on INT0#. P3.2 6 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B Signal Name Type Description 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 sets IE1 in the TCON register. If bit IT1 in this register is set, bit IE1 is set by a falling edge on INT1#. If bit IT1 is cleared, bit IE1 is set by a low level on INT1#. Timer 0 External Clock Input When timer 0 operates as a counter, a falling edge on the T0 pin increments the count. Timer 1 External Clock Input When timer 1 operates as a counter, a falling edge on the T1 pin increments the count. P3.3 Alternate Function T0 I P3.4 T1 I P3.5 Table 4-4. Signal Name DCLK DOUT DSEL Audio Interface Signal Description Type O O O Description DAC Data Bit Clock DAC Audio Data Output DAC Channel Select Signal DSEL is the sample rate clock output. DAC System Clock SCLK is the oversampling clock synchronized to the digital audio data (DOUT) and the channel selection signal (DSEL). Alternate Function - SCLK O - Table 4-5. Signal Name D+ D- USB Controller Signal Description Type I/O I/O Description USB Positive Data Upstream Port This pin requires an external 1.5 KΩ pull-up to VDD for full speed operation. USB Negative Data Upstream Port Alternate Function - Table 4-6. Signal Name MCLK MutiMediaCard Interface Signal Description Type O Description MMC Clock output Data or command clock transfer. MMC Command line Bidirectional command channel used for card initialization and data transfer commands. To avoid any parasitic current consumption, unused MCMD input must be polarized to VDD or VSS. MMC Data line Bidirectional data channel. To avoid any parasitic current consumption, unused MDAT input must be polarized to VDD or VSS. Alternate Function - MCMD I/O - MDAT I/O - 7 4341F–MP3–03/06 Table 4-7. Signal Name UART Signal Description Type Description Receive Serial Data RXD sends and receives data in serial I/O mode 0 and receives data in serial I/O modes 1, 2 and 3. Transmit Serial Data TXD outputs the shift clock in serial I/O mode 0 and transmits data in serial I/O modes 1, 2 and 3. Alternate Function RXD I/O P3.0 TXD O P3.1 Table 4-8. Signal Name SPI Controller Signal Description Type Description SPI Master Input Slave Output Data Line When in master mode, MISO receives data from the slave peripheral. When in slave mode, MISO outputs data to the master controller. SPI Master Output Slave Input Data Line When in master mode, MOSI outputs data to the slave peripheral. When in slave mode, MOSI receives data from the master controller. SPI Clock Line When in master mode, SCK outputs clock to the slave peripheral. When in slave mode, SCK receives clock from the master controller. SPI Slave Select Line When in controlled slave mode, SS enables the slave mode. Alternate Function MISO I/O P4.0 MOSI I/O P4.1 SCK I/O P4.2 SS I P4.3 Table 4-9. Signal Name TWI Controller Signal Description Type Description TWI Serial Clock When TWI controller is in master mode, SCL outputs the serial clock to the slave peripherals. When TWI controller is in slave mode, SCL receives clock from the master controller. TWI Serial Data SDA is the bidirectional Two Wire data line. Alternate Function SCL I/O - SDA I/O - Table 4-10. Signal Name KIN0 Keypad Interface Signal Description Type I Description Keypad Input Line Holding this pin high or low for 24 oscillator periods triggers a keypad interrupt. Alternate Function - 8 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B Table 4-11. Signal Name AIN1:0 ADCREFP ADCREFN A/D Converter Signal Description (AT8XSND2CMP3B only) Type I I I Description A/D Analog Inputs Analog Positive Voltage Reference Input Analog Negative Voltage Reference Input Alternate Function - Table 4-12. Signal Name External Access Signal Description Type Description Address Lines Upper address lines for the external bus. Multiplexed higher address and data lines for the IDE interface. Address/Data Lines Multiplexed lower address and data lines for the external memory or the IDE interface. Address Latch Enable Output ALE signals the start of an external bus cycle and indicates that valid address information is available on lines A7:0. An external latch is used to demultiplex the address from address/data bus. ISP Enable Input (AT89C51SND2C Only) This signal must be held to GND through a pull-down resistor at the falling reset to force execution of the internal bootloader. Read Signal Read signal asserted during external data memory read operation. Write Signal Write signal asserted during external data memory write operation. External Access Enable: EA must be externally held low to enable the device to fetch code from external program memory locations 0000H to FFFFH (RD). Alternate Function A15:8 I/O P2.7:0 AD7:0 I/O P0.7:0 ALE O - ISP I/O - RD O P3.7 WR EA(1) O P3.6 I - Note: 1. For ROM/Flash/ROMless Dice product versions only. Table 4-13. Signal Name System Signal Description Type Description Reset Input Holding this pin high 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-down resistor which allows the device to be reset by connecting a capacitor between this pin and VDD. Asserting RST when the chip is in Idle mode or Power-Down mode returns the chip to normal operation. Test Input Test mode entry signal. This pin must be set to VDD. Alternate Function RST I - TST I - 9 4341F–MP3–03/06 Table 4-14. Signal Name VDD Power Signal Description Type PWR Description Digital Supply Voltage C onnect these pins to +3V supply voltage. Circuit Ground C onnect these pins to ground. Analog Supply Voltage C onnect this pin to +3V supply voltage. Analog Ground C onnect this pin to ground. PLL Supply voltage C onnect this pin to +3V supply voltage. PLL Circuit Ground C onnect this pin to ground. USB Supply Voltage C onnect this pin to +3V supply voltage. USB Ground C onnect this pin to ground. Alternate Function - VSS GND - ADCVDD PWR - ADCVSS PWR - PVDD PWR - PVSS GND - UVDD PWR - UVSS GND - Table 4-15. Signal Name AUDVDD AUDVSS Audio Power Signal Description Type PWR GND Description Audio Digital Supply Voltage Audio Circuit Ground Connect these pins to ground. Audio Analog Circuit Ground for Electrostatic Discharge. Connect this pin to ground. Audio Voltage Reference pin for decoupling. Headset Driver Power Supply. Headset Driver Ground. Connect this pin to ground. Audio Amplifier Supply. Alternate Function - ESDVSS AUDVREF HSVDD HSVSS AUDVBAT GND PWR PWR GND PWR - Table 4-16. Signal Name LPHN HPN HPP CBP Stereo Audio Dac and Mono Power Amplifier Signal Description Type O O O O Description Low Power Audio Stage Output Negative Speaker Output Positivie Speaker Output Audio Amplifier Common Mode Voltage Decoupling Alternate Function - 10 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B Signal Name PAINN PAINP AUDRST MONON MONOP AUXP AUXN HSL HSR LINEL LINER INGND AUDVCM Type I I I O O I I O O I I I I Description Audio Amplifier Negative Input Audio Amplifier Positive Input Audio Reset (Active Low) Audio Negative Monaural Driver Output Audio Positive Monaural Driver Output Audio Mono Auxiliary Positive Input Audio Mono Auxiliary Negative Input Audio Left Channel Headset Driver Output Audio Right Channel Headset Driver Output Audio Left Channel Line In Audio Right Channel Line In Audio Line Signal Ground Pin for decoupling. Audio Common Mode reference for decoupling Alternate Function - 11 4341F–MP3–03/06 4.4 Internal Pin Structure Table 4-17. Detailed Internal Pin Structure Circuit(1) VDD Type Pins RTST Input TST VDD Watchdog Output P Input/Output RRST RST VSS 2 osc periods Latch Output VDD VDD VDD P1 P2 P3 Input/Output P3 P4 N VSS VDD P Input/Output N VSS VDD P0 MCMD MDAT ISP PSEN P Output N VSS ALE SCLK DCLK DOUT DSEL MCLK D+ D- Input/Output D+ D- Notes: 1. For information on resistors value, input/output levels, and drive capability, refer to the Section “DC Characteristics”, page 201. 2. When the Two Wire controller is enabled, P3 transistors are disabled allowing pseudo opendrain structure. 12 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B 5. Clock Controller The AT8xC51SND2C clock controller is based on an on-chip oscillator feeding an on-chip Phase Lock Loop (PLL). All internal clocks to the peripherals and CPU core are generated by this controller. 5.1 Oscillator The AT8xC51SND2C 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 such as a Pierce oscillator (see Figure 5-2). Value of capacitors and crystal characteristics are detailed in the section “DC Characteristics”. The oscillator outputs three different clocks: a clock for the PLL, a clock for the CPU core, and a clock for the peripherals as shown in Figure 5-1 . These clocks are either enabled or disabled, depending on the power reduction mode as detailed in the section “Power Management” on page 47. The peripheral clock is used to generate the Timer 0, Timer 1, MMC, SPI, and Port sampling clocks. Figure 5-1. Oscillator Block Diagram and Symbol ÷2 X1 0 1 Peripheral Clock CPU Core Clock X2 X2 CKCON.0 IDL PCON.0 PD PCON.1 Oscillator Clock CPU CLOCK OSC CLOCK PER CLOCK Peripheral Clock Symbol CPU Core Clock Symbol Oscillator Clock Symbol Figure 5-2. Crystal Connection X1 C1 Q C2 VSS X2 13 4341F–MP3–03/06 5.2 X2 Feature Unlike standard C51 products that require 12 oscillator clock periods per machine cycle, the AT8xC51SND2C need only 6 oscillator clock periods per machine cycle. This feature called the “X2 feature” can be enabled using the X2 bit(1) i n CKCON (see T able 5 -1 ) and allows the AT8xC51SND2C to operate in 6 or 12 oscillator clock periods per machine cycle. As shown in Figure 5-1, both CPU and peripheral clocks are affected by this feature. Figure 5-3 shows the X2 mode switching waveforms. After reset the standard mode is activated. In standard mode the CPU and peripheral clock frequency is the oscillator frequency divided by 2 while in X2 mode, it is the oscillator frequency. Note: 1. The X2 bit reset value depends on the X2B bit in the Hardware Security Byte (see Table 6-3 on page 22). Using the AT89C51SND2C (Flash Version) the system can boot either in standard or X2 mode depending on the X2B value. Using AT83SND2C (ROM Version) the system always boots in standard mode. X2B bit can be changed to X2 mode later by software. Figure 5-3. X1 X1 ÷ 2 X2 Bi Mode Switching Waveforms Clock STD Mode X2 Mode(1) STD Mode Note: 1. In order to prevent any incorrect operation while operating in X2 mode, user must be aware that all peripherals using clock frequency as time reference (timers, etc.) will have their time reference divided by 2. For example, a free running timer generating an interrupt every 20 ms will then generate an interrupt every 10 ms. 5.3 5.3.1 PLL PLL Description The AT8xC51SND2C PLL is used to generate internal high frequency clock (the PLL Clock) synchronized with an external low-frequency (the Oscillator Clock). The PLL clock provides the MP3 decoder, the audio interface, and the USB interface clocks. Figure 5-4 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 Table 5-2) 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 PFILT pin (see Figure 5-5). 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. 14 AT8xC51SND2C/MP3B 4341F–MP3–03/06 t AT8xC51SND2C/MP3B Figure 5-4. PLL Block Diagram and Symbol PLLCON.1 PFILT PLLEN N divider OSC CLOCK N6:0 Up PFLD Down PLOCK PLLCON.0 CHP Vref VCO PLL Clock R divider R9:0 OSCclk × ( R + 1 ) PLLclk = ---------------------------------------------N+1 PLL CLOCK PLL Clock Symbol Figure 5-5. PLL Filter Connection FILT R C1 VSS VSS C2 5.3.2 PLL Programming The PLL is programmed using the flow shown in F igure 5-6 . As soon as clock generation is enabled, the user must wait until the lock indicator is set to ensure the clock output is stable. The PLL clock frequency will depend on MP3 decoder clock and audio interface clock frequencies. Figure 5-6. PLL Programming Flow PLL Programming Configure Dividers N6:0 = xxxxxxb R9:0 = xxxxxxxxxxb Enable PLL PLLRES = 0 PLLEN = 1 PLL Locked? PLOCK = 1? 15 4341F–MP3–03/06 5.4 Registers Table 5-1. 7 TWIX2 CKCON Register CKCON (S:8Fh) – Clock Control Register 6 WDX2 Bit Mnemonic 5 4 SIX2 3 2 T1X2 1 T0X2 0 X2 Bit Number Description Two-Wire Clock Control Bit Set to select the oscillator clock divided by 2 as TWI clock input (X2 independent). C lear to select the peripheral clock as TWI clock input (X2 dependent). Watchdog Clock Control Bit Set to select the oscillator clock divided by 2 as watchdog clock input (X2 independent). C lear to select the peripheral clock as watchdog clock input (X2 dependent). Reserved The values read from this bit is indeterminate. Do not set this bit. Enhanced UART Clock (Mode 0 and 2) Control Bit Set to select the oscillator clock divided by 2 as UART clock input (X2 independent). C lear to select the peripheral clock as UART clock input (X2 dependent).. Reserved The values read from this bit is indeterminate. Do not set this bit. Timer 1 Clock Control Bit Set to select the oscillator clock divided by 2 as timer 1 clock input (X2 independent). C lear to select the peripheral clock as timer 1 clock input (X2 dependent). Timer 0 Clock Control Bit Set to select the oscillator clock divided by 2 as timer 0 clock input (X2 independent). C lear to select the peripheral clock as timer 0 clock input (X2 dependent). System Clock Control Bit C lear 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 - 4 SIX2 3 - 2 T1X2 1 T0X2 0 X2 Reset Value = 0000 000Xb (AT89C51SND2C) or 0000 0000b (AT83SND2C) Table 5-2. PLLCON Register PLLCON (S:E9h) – PLL Control Register 7 R1 6 R0 Bit Mnemonic R1:0 5 4 3 PLLRES 2 1 PLLEN 0 PLOCK Bit Number 7-6 Description PLL Least Significant Bits R Divider 2 LSB of the 10-bit R divider. Reserved The values read from these bits are always 0. Do not set these bits. PLL Reset Bit Set this bit to reset the PLL. C lear this bit to free the PLL and allow enabling. Reserved The value read from this bit is always 0. Do not set this bit. 5-4 - 3 PLLRES 2 - 16 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B Bit Number Bit Mnemonic Description PLL Enable Bit Set to enable the PLL. C lear to disable the PLL. PLL Lock Indicator S et by hardware when PLL is locked. C lear by hardware when PLL is unlocked. 1 PLLEN 0 PLOCK Reset Value = 0000 1000b Table 5-3. PLLNDIV Register PLLNDIV (S:EEh) – PLL N Divider Register 7 6 N6 Bit Mnemonic 5 N5 4 N4 3 N3 2 N2 1 N1 0 N0 Bit Number 7 Description Reserved The value read from this bit is always 0. Do not set this bit. PLL N Divider 7 - bit N divider. 6-0 N6:0 Reset Value = 0000 0000b Table 5-4. PLLRDIV Register PLLRDIV (S:EFh) – PLL R Divider Register 7 R9 6 R8 Bit Mnemonic R9:2 5 R7 4 R6 3 R5 2 R4 1 R3 0 R2 Bit Number 7-0 Description PLL Most Significant Bits R Divider 8 MSB of the 10-bit R divider. Reset Value = 0000 0000b 17 4341F–MP3–03/06 6. Program/Code Memory The AT8xC51SND2C execute up to 64K Bytes of program/code memory. Figure 6-1 shows the split of internal and external program/code memory spaces depending on the product. The AT83SND2C product provides the internal program/code memory in ROM memory while the AT89C51SND2C product provides it in Flash memory. These 2 products do not allow external code memory execution. The Flash memory increases EPROM and ROM functionality by in-circuit electrical erasure and programming. The high voltage needed for programming or erasing Flash cells is generated onchip using the standard VDD voltage, made possible by the internal charge pump. Thus, the AT89C51SND2C can be programmed using only one voltage and allows In-application software programming. Hardware programming mode is also available using common programming tools. Se e the application note ‘Pro grammin g T89C51 x and AT89C51x with Device Programmers’. The AT89C51SND2C implements an additional 4K Bytes of on-chip boot Flash memory provided in Flash memory. This boot memory is delivered programmed with a standard boot loader software allowing In-System Programming (ISP). It also contains some Application Programming Interface routines named API routines allowing In Application Programming (IAP) by using user’s own boot loader. Figure 6-1. Program/Code Memory Organization FFFFh FFFFh F000h FFFFh F000h 4K Bytes Boot Flash 64K Bytes Code ROM 64K Bytes Code Flash 0000h 0000h AT83SND2C AT89C51SND2C 18 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B 6.1 ROM Memory Architecture As shown in Figure 6-2 the AT83SND2C ROM memory is composed of one space detailed in the following paragraph. Figure 6-2. AT83SND2C Memory Architecture FFFFh 64K Bytes User ROM Memory 0000h 6.1.1 User Space This space is composed of a 64K Bytes ROM memory programmed during the manufacturing process. It contains the user’s application code. 6.2 Flash Memory Architecture As shown in Figure 6-3 the AT89C51SND2C Flash memory is composed of four spaces detailed in the following paragraphs. Figure 6-3. AT89C51SND2C Memory Architecture Hardware Security Extra Row FFFFh FFFFh 4K Bytes Flash Memory F000h Boot 64K Bytes User Flash Memory 0000h 6.2.1 User Space This space is composed of a 64K Bytes Flash memory organized in 512 pages of 128 Bytes. It contains the user’s application code. This space can be read or written by both software and hardware modes. 6.2.2 Boot Space This space is composed of a 4K Bytes Flash memory. It contains the boot loader for In-System Programming and the routines for In Application Programming. This space can only be read or written by hardware mode using a parallel programming tool. 19 4341F–MP3–03/06 6.2.3 Hardware Security Space This space is composed of one Byte: the Hardware Security Byte (HSB see Table 6-3) divided in 2 separate nibbles. The MSN contains the X2 mode configuration bit and the Boot Loader Jump Bit as detailed in Section “Boot Memory Execution”, page 20 and can be written by software w hile the LSN contains the lock system level to protect the memory content against piracy as detailed in Section “Hardware Security System”, page 20 and can only be written by hardware. 6.2.4 Extra Row Space This space is composed of 2 Bytes: • • The Software Boot Vector (SBV, see Table 6-4). This Byte is used by the software boot loader to build the boot address. The Software Security Byte (SSB, see Table 6-5). This Byte is used to lock the execution of some boot loader commands. 6.3 Hardware Security System The AT89C51SND2C implements three lock bits LB2:0 in the LSN of HSB (see Table 6-3) providing three levels of security for user’s program as described in T able 6-1 w hile the AT83SND2C is always set in read disabled mode. Level 0 is the level of an erased part and does not enable any security feature. Level 1 locks the hardware programming of both user and boot memories. Level 2 locks also hardware verifying of both user and boot memories Level 3 locks also the external execution. Table 6-1. Level 0 1 2 3(3) LB2 U U U P Lock Bit Features(1) LB1 U U P X LB0 U P X X Internal Execution Enable Enable Enable Enable External Execution Enable Enable Enable Disable Hardware Verifying Enable Enable Disable Disable Hardware Programming Enable Disable Disable Disable Software Programming Enable Enable Enable Enable Notes: 1. U means unprogrammed, P means programmed and X means don’t care (programmed or unprogrammed). 2. AT89C51SND2C products are delivered with third level programmed to ensure that the code programmed by software using ISP or user’s boot loader is secured from any hardware piracy. 6.4 Boot Memory Execution As internal C51 code space is limited to 64K Bytes, some mechanisms are implemented to allow boot memory to be mapped in the code space for execution at addresses from F000h to FFFFh. The boot memory is enabled by setting the ENBOOT bit in AUXR1 (see Figure 6-2). The three ways to set this bit are detailed in the following sections. 6.4.1 Software Boot Mapping The software way to set ENBOOT consists in writing to AUXR1 from the user’s software. This enables boot loader or API routines execution. 20 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B 6.4.2 Hardware Condition Boot Mapping The hardware condition is based on the ISP pin. When driving this pin to low level, the chip reset sets ENBOOT and forces the reset vector to F000h instead of 0000h in order to execute the boot loader software. As shown in Figure 6-4 the hardware condition always allows in-system recovery when user’s memory has been corrupted. 6.4.3 Programmed Condition Boot Mapping The programmed condition is based on the Boot Loader Jump Bit (BLJB) in HSB. As shown in Figure 6-4 when this bit is programmed (by hardware or software programming mode), the chip reset set ENBOOT and forces the reset vector to F000h instead of 0000h, in order to execute the boot loader software. Figure 6-4. Hardware Boot Process Algorithm RESET Hard Cond? ISP = L? Hardware Process Prog Cond? BLJB = P? Hard Cond Init ENBOOT = 1 PC = F000h FCON = 00h Standard Init ENBOOT = 0 PC = 0000h FCON = F0h Prog Cond Init ENBOOT = 1 PC = F000h FCON = F0h Software Process User’s Application Atmel’s Boot Loader The software process (boot loader) is detailed in the “Boot Loader Datasheet” Document. 6.5 Preventing Flash Corruption See Section “Reset Recommendation to Prevent Flash Corruption”, page 48. 21 4341F–MP3–03/06 6.6 Registers Table 6-2. 7 - AUXR1 Register AUXR1 (S:A2h) – Auxiliary Register 1 6 Bit Mnemonic 5 ENBOOT 4 3 GF3 2 0 1 0 DPS Bit Number 7-6 Description Reserved The value read from these bits are indeterminate. Do not set these bits. Enable Boot Flash Set this bit to map the boot Flash in the code space between at addresses F000h to FFFFh. C lear this bit to disable boot Flash. Reserved The value read from this bit is indeterminate. Do not set this bit. General Flag This bit is a general-purpose user flag. Always Zero This bit is stuck to logic 0 to allow INC AUXR1 instruction without affecting GF3 flag. Reserved for Data Pointer Extension. Data Pointer Select Bit Set to select second data pointer: DPTR1. C lear to select first data pointer: DPTR0. 5 ENBOOT 1 4 - 3 GF3 2 1 0 - 0 DPS Reset Value = XXXX 00X0b Note: 1. ENBOOT bit is only available in AT89C51SND2C product. 6.7 Hardware Bytes Table 6-3. 7 X2B HSB Byte – Hardware Security Byte 6 BLJB Bit Mnemonic X2B(1) 5 4 3 2 LB2 1 LB1 0 LB0 Bit Number Description X2 Bit Program this bit to start in X2 mode. U nprogram (erase) this bit to start in standard mode. Boot Loader Jump Bit Program this bit to execute the boot loader at address F000h on next reset. U nprogram (erase) this bit to execute user’s application at address 0000h on next reset. Reserved The value read from these bits is always unprogrammed. Do not program these bits. Reserved The value read from this bit is always unprogrammed. Do not program this bit. Hardware Lock Bits R efer to for bits description. 7 6 BLJB(2) 5-4 - 3 - 2-0 LB2:0 22 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B Reset Value = XXUU UXXX, UUUU UUUU after an hardware full chip erase. Note: 1. X2B initializes the X2 bit in CKCON during the reset phase. 2. In order to ensure boot loader activation at first power-up, AT89C51SND2C products are delivered with BLJB programmed. 3. Bits 0 to 3 (LSN) can only be programmed by hardware mode. Table 6-4. 7 ADD15 SBV Byte – Software Boot Vector 6 ADD14 Bit Mnemonic ADD15:8 5 ADD13 4 ADD12 3 ADD11 2 ADD10 1 ADD9 0 ADD8 Bit Number 7-0 Description MSB of the user’s boot loader 16-bit address location R efer to the boot loader datasheet for usage information (boot loader dependent) Reset Value = XXXX XXXX, UUUU UUUU after an hardware full chip erase. Table 6-5. 7 SSB7 SSB Byte – Software Security Byte 6 SSB6 Bit Mnemonic SSB7:0 5 SSB5 4 SSB4 3 SSB3 2 SSB2 1 SSB1 0 SSB0 Bit Number 7-0 Description Software Security Byte Data R efer to the boot loader datasheet for usage information (boot loader dependent) Reset Value = XXXX XXXX, UUUU UUUU after an hardware full chip erase. 23 4341F–MP3–03/06 7. Data Memory The AT8xC51SND2C provides data memory access in 2 different spaces: 1. The internal space mapped in three separate segments: – – – The lower 128 Bytes RAM segment The upper 128 Bytes RAM segment The expanded 2048 Bytes RAM segment 2. The external space. A fourth internal segment is available but dedicated to Special Function Registers, SFRs, (addresses 80h to FFh) accessible by direct addressing mode. For information on this segment, refer to the Section “Special Function Registers”, page 31. Figure 7-1 shows the internal and external data memory spaces organization. Figure 7-1. Internal and External Data Memory Organization FFFFh 64K Bytes External XRAM 7FFh FFh Upper 128 Bytes Internal RAM Indirect Addressing 80h 7Fh 80h Lower 128 Bytes Internal RAM Direct or Indirect Addressing FFh Special Function Registers Direct Addressing 2K Bytes Internal ERAM EXTRAM = 0 0800h EXTRAM = 1 0000h 00h 00h 7.1 7.1.1 Internal Space Lower 128 Bytes RAM The lower 128 Bytes of RAM (see Figure 7-2) are accessible from address 00h to 7Fh using direct or indirect addressing modes. The lowest 32 Bytes are grouped into 4 banks of 8 registers (R0 to R7). 2 bits RS0 and RS1 in PSW register (see Table 7-4 ) select which bank is in use according to Table 7-1. This allows more efficient use of code space, since register instructions are shorter than instructions that use direct addressing, and can be used for context switching in interrupt service routines. Table 7-1. RS1 0 0 1 1 Register Bank Selection RS0 0 1 0 1 Description Register bank 0 from 00h to 07h Register bank 1 from 08h to 0Fh Register bank 2 from 10h to 17h Register bank 3 from 18h to 1Fh 24 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B The next 16 Bytes above the register banks form a block of bit-addressable memory space. The C51 instruction set includes a wide selection of single-bit instructions, and the 128 bits in this area can be directly addressed by these instructions. The bit addresses in this area are 00h to 7Fh. Figure 7-2. Lower 128 Bytes Internal RAM Organization 7Fh 30h 2Fh 20h 18h 10h 08h 00h 1Fh 17h 0Fh 07h 4 Banks of 8 Registers R0-R7 Bit-Addressable Space (Bit Addresses 0-7Fh) 7.1.2 Upper 128 Bytes RAM The upper 128 Bytes of RAM are accessible from address 80h to FFh using only indirect addressing mode. 7.1.3 Expanded RAM The on-chip 2K Bytes of expanded RAM (ERAM) are accessible from address 0000h to 07FFh using indirect addressing mode through MOVX instructions. In this address range, EXTRAM bit in AUXR register (see Table 7-5) is used to select the ERAM (default) or the XRAM. As shown in F igure 7-1 when EXTRAM = 0, the ERAM is selected and when EXTRAM = 1, the XRAM is selected (see Section “External Space”). The ERAM memory can be resized using XRS1:0 bits in AUXR register to dynamically increase external access to the XRAM space. Table 7-2 details the selected ERAM size and address range. Table 7-2. XRS1 0 0 1 1 ERAM Size Selection XRS0 0 1 0 1 ERAM Size 256 Bytes 512 Bytes 1K Byte 2K Bytes Address 0 to 00FFh 0 to 01FFh 0 to 03FFh 0 to 07FFh Note: Lower 128 Bytes RAM, Upper 128 Bytes RAM, and expanded RAM are made of volatile memory cells. This means that the RAM content is indeterminate after power-up and must then be initialized properly. 7.2 7.2.1 External Space Memory Interface The external memory interface comprises the external bus (port 0 and port 2) as well as the bus control signals (RD, W R, and ALE). 25 4341F–MP3–03/06 Figure 7-3 s hows 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 7-3 describes the external memory interface signals. Figure 7-3. External Data Memory Interface Structure AT8xC51SND2C P2 ALE P0 AD7:0 Latch A7:0 A7:0 D7:0 RD WR OE WR A15:8 RAM PERIPHERAL A15:8 Table 7-3. Signal Name A15:8 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. Read Read signal output to external data memory. Write Write signal output to external memory. Alternate Function P2.7:0 AD7:0 I/O P0.7:0 ALE O - RD O P3.7 WR O P3.6 7.2.2 Page Access Mode The AT8xC51SND2C implement a feature called Page Access that disables the output of DPH on P2 when executing MOVX @DPTR instruction. Page Access is enable by setting the DPHDIS bit in AUXR register. Page Access is useful when application uses both ERAM and 256 Bytes of XRAM. In this case, software modifies intensively EXTRAM bit to select access to ERAM or XRAM and must save it if used in interrupt service routine. Page Access allows external access above 00FFh address without generating DPH on P2. Thus ERAM is accessed using MOVX @Ri or MOVX @DPTR with DPTR < 0100h, < 0200h, < 0400h or < 0800h depending on the XRS1:0 bits value. Then XRAM is accessed using MOVX @DPTR with DPTR ≥ 0800h regardless of XRS1:0 bits value while keeping P2 for general I/O usage. 7.2.3 External Bus Cycles This section describes the bus cycles the AT8xC51SND2C executes to read (see Figure 7-4), and write data (see Figure 7-5) in the external data memory. External memory cycle takes 6 CPU clock periods. This is equivalent to 12 oscillator clock period 26 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B in standard mode or 6 oscillator clock periods in X2 mode. For further information on X2 mode, refer to the Section “X2 Feature”, page 14. Slow peripherals can be accessed by stretching the read and write cycles. This is done using the M0 bit in AUXR register. Setting this bit changes the width of the RD and W R signals from 3 to 15 CPU clock periods. For simplicity, Figure 7-4 and Figure 7-5 depict the bus cycle waveforms in idealized form and do not provide precise timing information. For bus cycle timing parameters refer to the Section “AC Characteristics”. Figure 7-4. External Data Read Waveforms CPU Clock ALE RD(1) P0 P2 P2 DPL or Ri D7:0 DPH or P2(2),(3) Notes: 1. RD signal may be stretched using M0 bit in AUXR register. 2. When executing MOVX @Ri instruction, P2 outputs SFR content. 3. When executing MOVX @DPTR instruction, if DPHDIS is set (Page Access Mode), P2 outputs SFR content instead of DPH. Figure 7-5. External Data Write Waveforms CPU Clock ALE WR(1) P0 P2 P2 DPL or Ri D7:0 DPH or P2(2),(3) Notes: 1. WR signal may be stretched using M0 bit in AUXR register. 2. When executing MOVX @Ri instruction, P2 outputs SFR content. 3. When executing MOVX @DPTR instruction, if DPHDIS is set (Page Access Mode), P2 outputs SFR content instead of DPH. 7.3 7.3.1 Dual Data Pointer Description The AT8xC51SND2C implement a second data pointer for speeding up code execution and reducing code size in case of intensive usage of external memory accesses. 27 4341F–MP3–03/06 DPTR0 and DPTR1 are seen by the CPU as DPTR and are accessed using the SFR addresses 83h and 84h that are the DPH and DPL addresses. The DPS bit in AUXR1 register (see Table 62) is used to select whether DPTR is the data pointer 0 or the data pointer 1 (see Figure 7-6). Figure 7-6. Dual Data Pointer Implementation DPL0 DPL1 DPTR0 DPTR1 0 DPL 1 DPS DPH0 DPH1 0 AUXR1.0 DPTR DPH 1 7.3.2 Application Software can take advantage of the additional data pointers to both increase speed and reduce code size, for example, block operations (copy, compare, search …) are well served by using one data pointer as a “source” pointer and the other one as a “destination” pointer. Below is an example of block move implementation using the 2 pointers and coded in assembler. The latest C compiler also takes advantage of this feature by providing enhanced algorithm libraries. The INC instruction is a short (2 Bytes) and fast (6 CPU clocks) way to manipulate the DPS bit in the AUXR1 register. 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. ; ; ; ; ASCII block move using dual data pointers Modifies DPTR0, DPTR1, A and PSW Ends when encountering NULL character Note: DPS exits opposite of entry state unless an extra INC AUXR1 is added EQU 0A2h DPTR,#SOURCE AUXR1 DPTR,#DEST AUXR1 A,@DPTR DPTR AUXR1 @DPTR,A DPTR mv_loop ; ; ; ; ; ; ; ; ; ; address of SOURCE switch data pointers address of DEST switch data pointers get a Byte from SOURCE increment SOURCE address switch data pointers write the Byte to DEST increment DEST address check for NULL terminator AUXR1 move: mov inc mov mv_loop: inc movx inc inc movx inc jnz end_move: 28 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B 7.4 Registers Table 7-4. 7 CY PSW Register PSW (S:8Eh) – Program Status Word Register 6 AC Bit Mnemonic CY 5 F0 4 RS1 3 RS0 2 OV 1 F1 0 P Bit Number 7 Description Carry Flag C arry out from bit 1 of ALU operands. Auxiliary Carry Flag C arry out from bit 1 of addition operands. User Definable Flag 0 Register Bank Select Bits R efer to Table 7-1 for bits description. Overflow Flag Overflow set by arithmetic operations. User Definable Flag 1 Parity Bit Set when ACC contains an odd number of 1’s. C leared when ACC contains an even number of 1’s. 6 5 4-3 AC F0 RS1:0 2 1 OV F1 0 P Reset Value = 0000 0000b Table 7-5. AUXR Register AUXR (S:8Eh) – Auxiliary Control Register 7 6 EXT16 Bit Mnemonic 5 M0 4 DPHDIS 3 XRS1 2 XRS0 1 EXTRAM 0 AO Bit Number 7 Description Reserved The value read from this bit is indeterminate. Do not set this bit. External 16-bit Access Enable Bit Set to enable 16-bit access mode during MOVX instructions. Clear to disable 16-bit access mode and enable standard 8-bit access mode during MOVX instructions. External Memory Access Stretch Bit Set to stretch RD or WR signals duration to 15 CPU clock periods. Clear not to stretch RD or WR signals and set duration to 3 CPU clock periods. DPH Disable Bit Set to disable DPH output on P2 when executing MOVX @DPTR instruction. Clear to enable DPH output on P2 when executing MOVX @DPTR instruction. Expanded RAM Size Bits Refer to Table 7-2 for ERAM size description. 6 EXT16 5 M0 4 DPHDIS 3-2 XRS1:0 29 4341F–MP3–03/06 Bit Number Bit Mnemonic Description External RAM Enable Bit Set to select the external XRAM when executing MOVX @Ri or MOVX @DPTR instructions. Clear to select the internal expanded RAM when executing MOVX @Ri or MOVX @DPTR instructions. ALE Output Enable Bit Set to output the ALE signal only during MOVX instructions. Clear to output the ALE signal at a constant rate of FCPU/3. 1 EXTRAM 0 AO Reset Value = X000 1101b 30 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B 8. Special Function Registers The Special Function Registers (SFRs ) of the AT8xC51SND2C derivatives fall into the categories detailed in Table 8-1 to Table . The relative addresses of these SFRs are provided together with their reset values in Table 8-19 . In this table, the bit-addressable registers are identified by Note 1. Table 8-1. C51 Core SFRs 7 6 5 4 3 2 1 0 Mnemonic Add Name ACC B PSW SP DPL DPH E0h Accumulator F0h B Register D0h Program Status Word 81h Stack Pointer 82h Data Pointer Low Byte 83h Data Pointer High Byte CY AC F0 RS1 RS0 OV F1 P Table 8-2. System Management SFRs 7 SMOD1 NV7 6 SMOD0 EXT16 NV6 5 M0 ENBOOT 1) ( Mnemonic Add Name PCON AUXR AUXR1 NVERS 87h Power Control 8Eh Auxiliary Register 0 A2h Auxiliary Register 1 FBh Version Number 4 DPHDIS NV4 3 GF1 XRS1 GF3 NV3 2 GF0 XRS0 0 NV2 1 PD EXTRAM NV1 0 IDL AO DPS NV0 NV5 Note: 1. ENBOOT bit is only available in AT89C51SND2C product. Table 8-3. PLL and System Clock SFRs 7 R1 R9 6 R0 N6 R8 5 N5 R7 4 N4 R6 3 PLLRES N3 R5 2 N2 R4 1 PLLEN N1 R3 0 X2 PLOCK N0 R2 Mnemonic Add Name CKCON PLLCON PLLNDIV PLLRDIV 8Fh Clock Control E9h PLL Control EEh PLL N Divider EFh PLL R Divider Table 8-4. Interrupt SFRs 7 EA 6 EAUD EUSB IPHAUD IPLAUD IPHUSB 5 EMP3 IPHMP3 IPLMP3 4 ES EKB IPHS IPLS IPHKB 3 ET1 IPHT1 IPLT1 IPHADC 2 EX1 ESPI IPHX1 IPLX1 IPHSPI 1 ET0 EI2C IPHT0 IPLT0 IPHI2C 0 EX0 EMMC IPHX0 IPLX0 IPHMMC Mnemonic Add Name IEN0 IEN1 IPH0 IPL0 IPH1 A8h Interrupt Enable Control 0 B1h Interrupt Enable Control 1 B7h Interrupt Priority Control High 0 B8h Interrupt Priority Control Low 0 B3h Interrupt Priority Control High 1 31 4341F–MP3–03/06 Table 8-4. Interrupt SFRs (Continued) 7 6 IPLUSB 5 4 IPLKB 3 IPLADC 2 IPLSPI 1 IPLI2C 0 IPLMMC Mnemonic Add Name IPL1 B2h Interrupt Priority Control Low 1 Table 8-5. Port SFRs 7 6 5 4 3 2 1 0 Mnemonic Add Name P0 P2 P3 P4 80h 8-bit Port 0 A0h 8-bit Port 2 B0h 8-bit Port 3 C0h 4-bit Port 4 - - - - Table 8-6. Auxiliary SFRs 7 SDA 6 SCL 5 4 3 2 AUDCCL K 1 AUDCCS 0 KIN0 Mnemonic Add Name AUXCON 90h Auxiliary Control AUDCDOU AUDCDIN T Table 8-7. (1) Flash Memory SFR 7 FPL3 6 FPL2 5 FPL1 4 FPL0 3 FPS 2 FMOD1 1 FMOD0 0 FBUSY Mnemonic Add Name FCON D1h Flash Control Note: 1. FCON register is only available in AT89C51SND2C product. Table 8-8. Timer SFRs 7 TF1 GATE1 6 TR1 C/T1# 5 TF0 M11 4 TR0 M01 3 IE1 GATE0 2 IT1 C/T0# 1 IE0 M10 0 IT0 M00 Mnemonic Add Name TCON TMOD TL0 TH0 TL1 TH1 WDTRST WDTPRG 88h Timer/Counter 0 and 1 Control 89h Timer/Counter 0 and 1 Modes 8Ah Timer/Counter 0 Low Byte 8Ch Timer/Counter 0 High Byte 8Bh Timer/Counter 1 Low Byte 8Dh Timer/Counter 1 High Byte A6h Watchdog Timer Reset A7h Watchdog Timer Program - - - - - WTO2 WTO1 WTO0 Table 8-9. MP3 Decoder SFRs 7 MPEN MPANC 6 MPBBST MPREQ 5 CRCEN ERRLAY 4 MSKANC ERRSYN MPFREQ 3 MSKREQ ERRCRC MPBREQ 2 MSKLAY MPFS1 1 MSKSYN MPFS0 0 MSKCRC MPVER - Mnemonic Add Name MP3CON MP3STA MP3STA1 AAh MP3 Control C8h MP3 Status AFh MP3 Status 1 32 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B Table 8-9. MP3 Decoder SFRs (Continued) 7 MPD7 AND7 6 MPD6 AND6 5 MPD5 AND5 4 MPD4 AND4 VOL4 VOR4 BAS4 MED4 TRE4 MPCD4 3 MPD3 AND3 VOL3 VOR3 BAS3 MED3 TRE3 MPCD3 2 MPD2 AND2 VOL2 VOR2 BAS2 MED2 TRE2 MPCD2 1 MPD1 AND1 VOL1 VOR1 BAS1 MED1 TRE1 MPCD1 0 MPD0 AND0 VOL0 VOR0 BAS0 MED0 TRE0 MPCD0 Mnemonic Add Name MP3DAT MP3ANC MP3VOL MP3VOR MP3BAS MP3MED MP3TRE MP3CLK ACh MP3 Data ADh MP3 Ancillary Data 9Eh MP3 Audio Volume Control Left 9Fh MP3 Audio Volume Control Right B4h MP3 Audio Bass Control B5h MP3 Audio Medium Control B6h MP3 Audio Treble Control EBh MP3 Clock Divider Table 8-10. Audio Interface SFRs 7 JUST4 SRC SREQ AUD7 6 JUST3 DRQEN UDRN AUD6 5 JUST2 MSREQ AUBUSY AUD5 4 JUST1 MUDRN AUD4 AUCD4 3 JUST0 AUD3 AUCD3 2 POL DUP1 AUD2 AUCD2 1 DSIZ DUP0 AUD1 AUCD1 0 HLR AUDEN AUD0 AUCD0 Mnemonic Add Name AUDCON0 AUDCON1 AUDSTA AUDDAT AUDCLK 9Ah Audio Control 0 9Bh Audio Control 1 9Ch Audio Status 9Dh Audio Data ECh Audio Clock Divider Table 8-11. USB Controller SFRs 7 USBE FEN EPEN DIR FDAT7 FNUM7 6 SUSPCL K UADD6 NAKIEN RXOUTB 1 FDAT6 BYCT6 FNUM6 5 SDRMWU P UADD5 WUPCPU 4 UADD4 EORINT 3 UPRSM UADD3 SOFINT ESOFINT DTGL STLCRC FDAT3 BYCT3 FNUM3 2 RMWUPE UADD2 EPDIR RXSETU P EP2RST EP2INT EP2INTE FDAT2 BYCT2 FNUM2 FNUM10 1 CONFG UADD1 EPNUM1 0 FADDEN UADD0 SPINT ESPINT EPNUM0 Mnemonic Add Name USBCON USBADDR USBINT USBIEN UEPNUM BCh USB Global Control C6h USB Address BDh USB Global Interrupt BEh USB Global Interrupt Enable C7h USB Endpoint Number EWUPCP EEORINT U NAKOUT STALLRQ FDAT5 BYCT5 FNUM5 CRCOK NAKIN TXRDY FDAT4 BYCT4 FNUM4 CRCERR - UEPCONX D4h USB Endpoint X Control UEPSTAX UEPRST UEPINT UEPIEN UEPDATX UBYCTX UFNUML UFNUMH USBCLK CEh USB Endpoint X Status D5h USB Endpoint Reset F8h USB Endpoint Interrupt C2h USB Endpoint Interrupt Enable CFh USB Endpoint X FIFO Data E2h USB Endpoint X Byte Counter BAh USB Frame Number Low BBh USB Frame Number High EAh USB Clock Divider EPTYPE1 EPTYPE0 RXOUTB 0 EP1RST EP1INT EP1INTE FDAT1 BYCT1 FNUM1 FNUM9 USBCD1 TXCMP EP0RST EP0INT EP0INTE FDAT0 BYCT0 FNUM0 FNUM8 USBCD0 33 4341F–MP3–03/06 Table 8-12. MMC Controller SFRs 7 DRPTR BLEN3 MMCEN MCBI MCBM MC7 6 DTPTR BLEN2 DCR EORI EORM MC6 5 CRPTR BLEN1 CCR CBUSY EOCI EOCM MC5 4 CTPTR BLEN0 CRC16S EOFI EOFM MC4 3 MBLOCK DATDIR DATFS F2FI F2FM MC3 2 DFMT DATEN DATD1 CRC7S F1FI F1FM MC2 1 RFMT RESPEN DATD0 RESPFS F2EI F2EM MC1 0 CRCDIS CMDEN FLOWC CFLCK F1EI F1EM MC0 Mnemonic Add Name MMCON0 MMCON1 MMCON2 MMSTA MMINT MMMSK MMCMD E4h MMC Control 0 E5h MMC Control 1 E6h MMC Control 2 DEh MMC Control and Status E7h MMC Interrupt DFh MMC Interrupt Mask DD h DC h MMC Command MMDAT MMCLK MMC Data MD7 MMCD7 MD6 MMCD6 MD5 MMCD5 MD4 MMCD4 MD3 MMCD3 MD2 MMCD2 MD1 MMCD1 MD0 MMCD0 EDh MMC Clock Divider Table 8-13. IDE Interface SFR 7 D15 6 D14 5 D13 4 D12 3 D11 2 D10 1 D9 0 D8 Mnemonic Add Name DAT16H F9h High Order Data Byte Table 8-14. Serial I/O Port SFRs 7 FE/SM0 6 SM1 5 SM2 4 REN 3 TB8 2 RB8 1 TI 0 RI Mnemonic Add Name SCON SBUF SADEN SADDR BDRCON BRL 98h Serial Control 99h Serial Data Buffer B9h Slave Address Mask A9h Slave Address 92h Baud Rate Control 91h Baud Rate Reload BRR TBCK RBCK SPD SRC Table 8-15. SPI Controller SFRs 7 SPR2 SPIF SPD7 6 SPEN WCOL SPD6 5 SSDIS SPD5 4 MSTR MODF SPD4 3 CPOL SPD3 2 CPHA SPD2 1 SPR1 SPD1 0 SPR0 SPD0 Mnemonic Add Name SPCON SPSTA SPDAT C3h SPI Control C4h SPI Status C5h SPI Data 34 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B Table 8-16. Two Wire Controller SFRs 7 SSCR2 SSC4 SSD7 SSA7 6 SSPE SSC3 SSD6 SSA6 5 SSSTA SSC2 SSD5 SSA5 4 SSSTO SSC1 SSD4 SSA4 3 SSI SSC0 SSD3 SSA3 2 SSAA 0 SSD2 SSA2 1 SSCR1 0 SSD1 SSA1 0 SSCR0 0 SSD0 SSGC Mnemonic Add Name SSCON SSSTA SSDAT SSADR 93h Synchronous Serial Control 94h Synchronous Serial Status 95h Synchronous Serial Data 96h Synchronous Serial Address Table 8-17. Keyboard Interface SFRs 7 KPDE 6 5 4 KINL0 3 2 1 0 KINM0 KINF0 Mnemonic Add Name KBCON KBSTA A3h Keyboard Control A4h Keyboard Status Table 8-18. Mnemonic ADCON ADCLK ADDL ADDH A/D Controller SFRs Add F3h F2h F4h F5h Name ADC Control ADC Clock Divider ADC Data Low Byte ADC Data High Byte 7 ADAT9 6 ADIDL ADAT8 5 ADEN ADAT7 4 ADEOC ADCD4 ADAT6 3 ADSST ADCD3 ADAT5 2 ADCD2 ADAT4 1 ADCD1 ADAT1 ADAT3 0 ADCS ADCD0 ADAT0 ADAT2 35 4341F–MP3–03/06 Table 8-19. SFR Addresses and Reset Values 0/8 1/9 DAT16H XXXX XXXX ADCLK 0000 0000 PLLCON 0000 1000 USBCLK 0000 0000 UBYCTLX 0000 0000 2/A 3/B NVERS XXXX XXXX (2) ADCON 0000 0000 MP3CLK 0000 0000 ADDL 0000 0000 AUDCLK 0000 0000 MMCON0 0000 0000 MMDAT 1111 1111 FCON(3) 1111 0000(4) UEPCONX 1000 0000 ADDH 0000 0000 MMCLK 0000 0000 MMCON1 0000 0000 MMCMD 1111 1111 UEPRST 0000 0000 UEPSTAX 0000 0000 UEPIEN 0000 0000 SADEN 0000 0000 IEN1 0000 0000 SADDR 0000 0000 UFNUML 0000 0000 IPL1 0000 0000 MP3CON 0011 1111 AUXR1 XXXX 00X0 SBUF XXXX XXXX BRL 0000 0000 TMOD 0000 0000 SP 0000 0111 1/9 AUDCON0 0000 1000 BDRCON XXX0 0000 TL0 0000 0000 DPL 0000 0000 2/A KBCON 0000 1111 AUDCON1 1011 0010 SSCON 0000 0000 TL1 0000 0000 DPH 0000 0000 3/B 4/C 5/D 6/E SPCON 0001 0100 UFNUMH 0000 0000 IPH1 0000 0000 SPSTA 0000 0000 USBCON 0000 0000 MP3BAS 0000 0000 MP3DAT 0000 0000 KBSTA 0000 0000 AUDSTA 1100 0000 SSSTA 1111 1000 TH0 0000 0000 AUDDAT 1111 1111 SSDAT 1111 1111 TH1 0000 0000 SPDAT XXXX XXXX USBINT 0000 0000 MP3MED 0000 0000 MP3ANC 0000 0000 WDTRST XXX XXXX MP3VOL 0000 0000 SSADR 1111 1110 AUXR X000 1101 CKCON 0000 000X(5) PCON 00XX 0000 7/F USBADDR 0000 0000 USBIEN 0001 0000 MP3TRE 0000 0000 IPH0 X000 0000 MP3STA1 0100 0001 WDTPRG XXXX X000 MP3VOR 0000 0000 UEPDATX XXXX XXXX UEPNUM 0000 0000 PLLNDIV 0000 0000 MMCON2 0000 0000 MMSTA 0000 0000 PLLRDIV 0000 0000 MMINT 0000 0011 MMMSK 1111 1111 4/C 5/D 6/E 7/F FFh F8h UEPINT 0000 0000 B(1) 0000 0000 F0h F7h E8h ACC(1) 0000 0000 P5(1) XXXX 1111 PSW(1) 0000 0000 MP3STA(1) 0000 0001 P4(1) 1111 1111 IPL0(1) X000 0000 P3(1) 1111 1111 IEN0(1) 0000 0000 P2(1) 1111 1111 SCON 0000 0000 AUXCON(1) 1111 1111 TCON(1) 0000 0000 P0(1) 1111 1111 0/8 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 Reserved Notes: 1. SFR registers with least significant nibble address equal to 0 or 8 are bit-addressable. 2. NVERS reset value depends on the silicon version: 1000 0100 for AT89C51SND2C product and 0000 0001 for AT83SND2C product. 3. FCON register is only available in AT89C51SND2C product. 4. FCON reset value is 00h in case of reset with hardware condition. 5. CKCON reset value depends on the X2B bit (programmed or unprogrammed) in the Hardware Byte. 36 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B 9. Interrupt System The AT8xC51SND2C, like other control-oriented computer architectures, employ a program interrupt method. This operation branches to a subroutine and performs some service in response to the interrupt. When the subroutine completes, execution resumes at the point where the interrupt occurred. Interrupts may occur as a result of internal AT8xC51SND2C activity (e.g., timer overflow) or at the initiation of electrical signals external to the microcontroller (e.g., keyboard). In all cases, interrupt operation is programmed by the system designer, who determines priority of interrupt service relative to normal code execution and other interrupt service routines. All of the interrupt sources are enabled or disabled by the system designer and may be manipulated dynamically. A typical interrupt event chain occurs as follows: • • • An internal or external device initiates an interrupt-request signal. The AT8xC51SND2C, latches this event into a flag buffer. The priority of the flag is compared to the priority of other interrupts by the interrupt handler. A high priority causes the handler to set an interrupt flag. This signals the instruction execution unit to execute a context switch. This context switch breaks the current flow of instruction sequences. The execution unit completes the current instruction prior to a save of the program counter (PC) and reloads the PC with the start address of a software service routine. The software service routine executes assigned tasks and as a final activity performs a RETI (return from interrupt) instruction. This instruction signals completion of the interrupt, resets the interrupt-in-progress priority and reloads the program counter. Program operation then continues from the original point of interruption. Interrupt System Signals Type I Description External Interrupt 0 S ee section "External Interrupts", page 40. External Interrupt 1 S ee section “External Interrupts”, page 40. Keyboard Interrupt Input S ee section “Keyboard Interface”, page 204. Alternate Function P3.2 • Table 9-1. Signal Name INT0 INT1 I P3.3 KIN0 I - Six interrupt registers are used to control the interrupt system. 2 8-bit registers are used to enable separately the interrupt sources: IEN0 and IEN1 registers (see Table 9-4 and Table 9-5). Four 8-bit registers are used to establish the priority level of the different sources: IPH0, IPL0, IPH1 and IPL1 registers (see Table 9-6 to Table 9-9). 9.1 Interrupt System Priorities Each of the interrupt sources on the AT8xC51SND2C can be individually programmed to one of four priority levels. This is accomplished by one bit in the Interrupt Priority High registers (IPH0 and IPH1) and one bit in the Interrupt Priority Low registers (IPL0 and IPL1). This provides each interrupt source four possible priority levels according to Table 9-2. 37 4341F–MP3–03/06 Table 9-2. Priority Levels IPLxx 0 1 0 1 Priority Level 0 Lowest 1 2 3 Highest IPHxx 0 0 1 1 A low-priority interrupt is always interrupted by a higher priority interrupt but not by another interrupt of lower or equal priority. Higher priority interrupts are serviced before lower priority interrupts. The response to simultaneous occurrence of equal priority interrupts is determined by an internal hardware polling sequence detailed in T able 9 -3. Thus, within each priority level there is a second priority structure determined by the polling sequence. The interrupt control system is shown in Figure 9-1. Table 9-3. Priority within Same Level Interrupt Request Flag Cleared by Hardware (H) or by Software (S) H if edge, S if level H H if edge, S if level H S S S S S S S S S - Interrupt Name INT0 Timer 0 INT1 Timer 1 Serial Port MP3 Decoder Audio Interface MMC Interface Two Wire Controller SPI Controller A to D Converter Keyboard Reserved USB Reserved Priority Number 0 (Highest Priority) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 (Lowest Priority) Interrupt Address Vectors C:0003h C:000Bh C:0013h C:001Bh C:0023h C:002Bh C:0033h C:003Bh C:0043h C:004Bh C:0053h C:005Bh C:0063h C:006Bh C:0073h 38 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B Figure 9-1. Interrupt Control System INT0 External Interrupt 0 EX0 IEN0.0 00 01 10 11 00 01 10 11 00 01 10 11 00 01 10 11 00 01 10 11 00 01 10 11 00 01 10 11 00 01 10 11 00 01 10 11 00 01 10 11 00 01 10 11 00 01 10 11 00 01 10 11 Highest Priority Interrupts Timer 0 ET0 IEN0.1 INT1 External Interrupt 1 EX1 IEN0.2 Timer 1 ET1 TXD RXD IEN0.3 Serial Port ES IEN0.4 MP3 Decoder EMP3 IEN0.5 Audio Interface EAUD MCLK MDAT MCMD SCL SDA SCK SI SO IEN0.6 MMC Controller EMMC IEN1.0 TWI Controller EI2C IEN1.1 SPI Controller ESPI IEN1.2 AIN1:0 A to D Converter EADC IEN1.3 KIN0 Keyboard EKB D+ D- IEN1.4 USB Controller EUSB IEN1.6 EA IEN0.7 Interrupt Enable IPH/L Priority Enable Lowest Priority Interrupts 39 4341F–MP3–03/06 9.2 9.2.1 External Interrupts INT1:0 Inputs External interrupts INT0 and INT1 (INTn, n = 0 or 1) pins may each be programmed to be leveltriggered or edge-triggered, dependent upon bits IT0 and IT1 (ITn, n = 0 or 1) in TCON register as shown in Figure 9-2. If ITn = 0, INTn is triggered by a low level at the pin. If ITn = 1, INTn is negative-edge triggered. External interrupts are enabled with bits EX0 and EX1 (EXn, n = 0 or 1) in IEN0. Events on INTn set the interrupt request flag IEn in TCON register. If the interrupt is edge-triggered, the request flag is cleared by hardware when vectoring to the interrupt service routine. If the interrupt is level-triggered, the interrupt service routine must clear the request flag and the interrupt must be deasserted before the end of the interrupt service routine. INT0 and INT1 inputs provide both the capability to exit from Power-down mode on low level signals as detailed in section “Exiting Power-down Mode”, page 50. Figure 9-2. INT1:0 Input Circuitry 0 INT0/1 IE0/1 1 TCON.1/3 INT0/1 Interrupt Request EX0/1 IEN0.0/2 IT0/1 TCON.0/2 9.2.2 KIN0 Inputs External interrupts KIN0 provides the capability to connect a keyboard. For detailed information on this inputs, refer to section “Keyboard Interface”, page 204. 9.2.3 Input Sampling External interrupt pins (INT1:0 and KIN0) are sampled once per peripheral cycle (6 peripheral clock periods) (see Figure 9-3). A level-triggered interrupt pin held low or high for more than 6 peripheral clock periods (12 oscillator in standard mode or 6 oscillator clock periods in X2 mode) guarantees detection. Edge-triggered external interrupts must hold the request pin low for at least 6 peripheral clock periods. Figure 9-3. Minimum Pulse Timings > 1 cycle Level-Triggered Interrupt 1 Peripheral Cycle 1 cycle 40 AT8xC51SND2C/MP3B 4341F–MP3–03/06 > Edge-Triggered Interrupt 1 Peripheral Cycle 1 cycle AT8xC51SND2C/MP3B 9.3 Registers Table 9-4. 7 EA IEN0 Register IEN0 (S:A8h) – Interrupt Enable Register 0 6 EAUD Bit Mnemonic 5 EMP3 4 ES 3 ET1 2 EX1 1 ET0 0 EX0 Bit Number Description Enable All Interrupt Bit Set to enable all interrupts. C lear to disable all interrupts. If EA = 1, each interrupt source is individually enabled or disabled by setting or clearing its interrupt enable bit. Audio Interface Interrupt Enable Bit Set to enable audio interface interrupt. C lear to disable audio interface interrupt. MP3 Decoder Interrupt Enable Bit Set to enable MP3 decoder interrupt. C lear to disable MP3 decoder interrupt. Serial Port Interrupt Enable Bit Set to enable serial port interrupt. C lear to disable serial port interrupt. Timer 1 Overflow Interrupt Enable Bit Set to enable timer 1 overflow interrupt. C lear to disable timer 1 overflow interrupt. External Interrupt 1 Enable bit Set to enable external interrupt 1. C lear to disable external interrupt 1. Timer 0 Overflow Interrupt Enable Bit Set to enable timer 0 overflow interrupt. C lear to disable timer 0 overflow interrupt. External Interrupt 0 Enable Bit Set to enable external interrupt 0. C lear to disable external interrupt 0. 7 EA 6 EAUD 5 EMP3 4 ES 3 ET1 2 EX1 1 ET0 0 EX0 Reset Value = 0000 0000b 41 4341F–MP3–03/06 Table 9-5. 7 - IEN1 Register IEN1 (S:B1h) – Interrupt Enable Register 1 6 EUSB Bit Mnemonic 5 4 EKB 3 2 ESPI 1 EI2C 0 EMMC Bit Number 7 Description Reserved The value read from this bit is always 0. Do not set this bit. USB Interface Interrupt Enable Bit Set this bit to enable USB interrupts. C lear this bit to disable USB interrupts. Reserved The value read from this bit is always 0. Do not set this bit. Keyboard Interface Interrupt Enable Bit S et to enable Keyboard interrupt. C lear to disable Keyboard interrupt. A to D Converter Interrupt Enable Bit Set to enable ADC interrupt. C lear to disable ADC interrupt. SPI Controller Interrupt Enable Bit Set to enable SPI interrupt. C lear to disable SPI interrupt. Two Wire Controller Interrupt Enable Bit Set to enable Two Wire interrupt. C lear to disable Two Wire interrupt. MMC Interface Interrupt Enable Bit Set to enable MMC interrupt. C lear to disable MMC interrupt. 6 EUSB 5 - 4 EKB 3 EADC 2 ESPI 1 EI2C 0 EMMC Reset Value = 0000 0000b 42 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B Table 9-6. 7 - IPH0 Register IPH0 (S:B7h) – Interrupt Priority High Register 0 6 IPHAUD Bit Mnemonic 5 IPHMP3 4 IPHS 3 IPHT1 2 IPHX1 1 IPHT0 0 IPHX0 Bit Number 7 Description Reserved The value read from this bit is indeterminate. Do not set this bit. Audio Interface Interrupt Priority Level MSB R efer to Table 9-2 for priority level description. MP3 Decoder Interrupt Priority Level MSB R efer to Table 9-2 for priority level description. Serial Port Interrupt Priority Level MSB R efer to Table 9-2 for priority level description. Timer 1 Interrupt Priority Level MSB R efer to Table 9-2 for priority level description. External Interrupt 1 Priority Level MSB R efer to Table 9-2 for priority level description. Timer 0 Interrupt Priority Level MSB R efer to Table 9-2 for priority level description. External Interrupt 0 Priority Level MSB R efer to Table 9-2 for priority level description. 6 IPHAUD 5 IPHMP3 4 IPHS 3 IPHT1 2 IPHX1 1 IPHT0 0 IPHX0 Reset Value = X000 0000b 43 4341F–MP3–03/06 Table 9-7. 7 - IPH1 Register IPH1 (S:B3h) – Interrupt Priority High Register 1 6 IPHUSB Bit Mnemonic 5 4 IPHKB 3 2 IPHSPI 1 IPHI2C 0 IPHMMC Bit Number 7 Description Reserved The value read from this bit is always 0. Do not set this bit. USB Interrupt Priority Level MSB R efer to Table 9-2 for priority level description. Reserved The value read from this bit is always 0. Do not set this bit. Keyboard Interrupt Priority Level MSB R efer to Table 9-2 for priority level description. A to D Converter Interrupt Priority Level MSB R efer to Table 9-2 for priority level description. SPI Interrupt Priority Level MSB R efer to Table 9-2 for priority level description. Two Wire Controller Interrupt Priority Level MSB R efer to Table 9-2 for priority level description. MMC Interrupt Priority Level MSB R efer to Table 9-2 for priority level description. 6 IPHUSB 5 - 4 IPHKB 3 IPHADC 2 IPHSPI 1 IPHI2C 0 IPHMMC Reset Value = 0000 0000b 44 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B Table 9-8. 7 - IPL0 Register IPL0 (S:B8h) - Interrupt Priority Low Register 0 6 IPLAUD Bit Mnemonic 5 IPLMP3 4 IPLS 3 IPLT1 2 IPLX1 1 IPLT0 0 IPLX0 Bit Number 7 Description Reserved The value read from this bit is indeterminate. Do not set this bit. Audio Interface Interrupt Priority Level LSB R efer to Table 9-2 for priority level description. MP3 Decoder Interrupt Priority Level LSB R efer to Table 9-2 for priority level description. Serial Port Interrupt Priority Level LSB R efer to Table 9-2 for priority level description. Timer 1 Interrupt Priority Level LSB R efer to Table 9-2 for priority level description. External Interrupt 1 Priority Level LSB R efer to Table 9-2 for priority level description. Timer 0 Interrupt Priority Level LSB R efer to Table 9-2 for priority level description. External Interrupt 0 Priority Level LSB R efer to Table 9-2 for priority level description. 6 IPLAUD 5 IPLMP3 4 IPLS 3 IPLT1 2 IPLX1 1 IPLT0 0 IPLX0 Reset Value = X000 0000b 45 4341F–MP3–03/06 Table 9-9. 7 - IPL1 Register IPL1 (S:B2h) – Interrupt Priority Low Register 1 6 IPLUSB Bit Mnemonic 5 4 IPLKB 3 2 IPLSPI 1 IPLI2C 0 IPLMMC Bit Number 7 Description Reserved The value read from this bit is always 0. Do not set this bit. USB Interrupt Priority Level LSB R efer to Table 9-2 for priority level description. Reserved The value read from this bit is always 0. Do not set this bit. Keyboard Interrupt Priority Level LSB R efer to Table 9-2 for priority level description. A to D Converter Interrupt Priority Level LSB R efer to Table 9-2 for priority level description. SPI Interrupt Priority Level LSB R efer to Table 9-2 for priority level description. Two Wire Controller Interrupt Priority Level LSB R efer to Table 9-2 for priority level description. MMC Interrupt Priority Level LSB R efer to Table 9-2 for priority level description. 6 IPLUSB 5 - 4 IPLKB 3 IPLADC 2 IPLSPI 1 IPLI2C 0 IPLMMC Reset Value = 0000 0000b 46 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B 10. Power Management 2 power reduction modes are implemented in the AT8xC51SND2C: the Idle mode and the Power-down mode. These modes are detailed in the following sections. In addition to these power reduction modes, the clocks of the core and peripherals can be dynamically divided by 2 using the X2 mode detailed in section “X2 Feature”, page 14. 10.1 Reset In order to start-up (cold reset) or to restart (warm reset) properly the microcontroller, an high level has to be applied on the RST pin. A bad level leads to a wrong initialization of the internal registers like SFRs, Program Counter… and to unpredictable behavior of the microcontroller. A proper device reset initializes the AT8xC51SND2C and vectors the CPU to address 0000h. RST input has a pull-down resistor allowing power-on reset by simply connecting an external capacitor to VDD as shown in Figure 10-1. A warm reset can be applied either directly on the RST pin or indirectly by an internal reset source such as the watchdog timer. Resistor value and input characteristics are discussed in the Section “DC Characteristics” of the AT8xC51SND2C datasheet. The status of the Port pins during reset is detailed in Table 10-1. Figure 10-1. Reset Circuitry and Power-On Reset VDD From Internal Reset Source To CPU Core and Peripherals VDD P RST RRST + RST VSS RST input circuitry Power-on Reset Table 10-1. Mode Reset Idle Power-down Pin Conditions in Special Operating Modes Port 0 Floating Data Data Port 1 High Data Data Port 2 High Data Data Port 3 High Data Data Port 4 High Data Data Port 5 High Data Data MMC Floating Data Data Audio 1 Data Data Note: 1. Refer to section “Audio Output Interface”, page 74. 10.1.1 Cold Reset 2 conditions are required before enabling a CPU start-up: • • VDD must reach the specified VDD range The level on X1 input pin must be outside the specification (VIH, VIL) If one of these 2 conditions are not met, the microcontroller does not start correctly and can execute an instruction fetch from anywhere in the program space. An active level applied on the RST pin must be maintained till both of the above conditions are met. A reset is active when the level VIH1 is reached and when the pulse width covers the period of time where VDD and the oscillator are not stabilized. 2 parameters have to be taken into account to determine the reset pulse width: • • VDD rise time, Oscillator startup time. 47 4341F–MP3–03/06 To determine the capacitor value to implement, the highest value of these 2 parameters has to be chosen. Table 10-2 gives some capacitor values examples for a minimum RRST of 50 KΩ and different oscillator startup and VDD rise times. Table 10-2. Minimum Reset Capacitor Value for a 50 kΩ Pull-down Resistor (1) VDD Rise Time 1 ms 820 nF 2.7 µF 10 ms 1.2 µF 3.9 µF 100 ms 12 µF 12 µF Oscillator Start-Up Time 5 ms 20 ms Note: 1. These values assume VDD starts from 0V to the nominal value. If the time between 2 on/off sequences is too fast, the power-supply de-coupling capacitors may not be fully discharged, leading to a bad reset sequence. 10.1.2 Warm Reset To achieve a valid reset, the reset signal must be maintained for at least 2 machine cycles (24 oscillator clock periods) while the oscillator is running. The number of clock periods is mode independent (X2 or X1). 10.1.3 Watchdog Reset As detailed in section “Watchdog Timer”, page 60, the WDT generates a 96-clock period pulse on the RST pin. In order to properly propagate this pulse to the rest of the application in case of external capacitor or power-supply supervisor circuit, a 1 kΩ resistor must be added as shown in Figure 10-2. Figure 10-2. Reset Circuitry for WDT Reset-out Usage VDD + VDD From WDT Reset Source To CPU Core and Peripherals RST VDD 1K P RST RRST VSS VSS To Other On-board Circuitry 10.2 Reset Recommendation to Prevent Flash Corruption An example of bad initialization situation may occur in an instance where the bit ENBOOT in AUXR1 register is initialized from the hardware bit BLJB upon reset. Since this bit allows mapping of the bootloader in the code area, a reset failure can be critical. If one wants the ENBOOT cleared in order to unmap the boot from the code area (yet due to a bad reset) the bit ENBOOT in SFRs may be set. If the value of Program Counter is accidently in the range of the boot memory addresses then a Flash access (write or erase) may corrupt the Flash on-chip memory. It is recommended to use an external reset circuitry featuring power supply monitoring to prevent system malfunction during periods of insufficient power supply voltage (power supply failure, power supply switched off). 48 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B 10.3 Idle Mode Idle mode is a power reduction mode that reduces the power consumption. In this mode, program execution halts. Idle mode freezes the clock to the CPU at known states while the peripherals continue to be clocked (refer to s ection “ Oscillator”, page 13). The CPU status before entering Idle mode is preserved, i.e., the program counter and program status word register retain their data for the duration of Idle mode. The contents of the SFRs and RAM are also retained. The status of the Port pins during Idle mode is detailed in Table 10-1. 10.3.1 Entering Idle Mode To enter Idle mode, the user must set the IDL bit in PCON register (see T able 10-3 ). The A T8xC51SND2C enters Idle mode upon execution of the instruction that sets IDL bit. The instruction that sets IDL bit is the last instruction executed. Note: If IDL bit and PD bit are set simultaneously, the AT8xC51SND2C enter Power-down mode. Then it does not go in Idle mode when exiting Power-down mode. 10.3.2 Exiting Idle Mode There are 2 ways to exit Idle mode: 1. Generate an enabled interrupt. – Hardware clears IDL bit in PCON register which restores the clock to the CPU. Execution resumes with the interrupt service routine. Upon completion of the interrupt service routine, program execution resumes with the instruction immediately following the instruction that activated Idle mode. The general-purpose flags (GF1 and GF0 in PCON register) may be used to indicate whether an interrupt occurred during normal operation or during Idle mode. When Idle mode is exited by an interrupt, the interrupt service routine may examine GF1 and GF0. A logic high on the RST pin clears IDL bit in PCON register directly and asynchronously. This restores the clock to the CPU. Program execution momentarily resumes with the instruction immediately following the instruction that activated the Idle mode and may continue for a number of clock cycles before the internal reset algorithm takes control. Reset initializes the AT8xC51SND2C and vectors the CPU to address C:0000h. During the time that execution resumes, the internal RAM cannot be accessed; however, it is possible for the Port pins to be accessed. To avoid unexpected outputs at the Port pins, the instruction immediately following the instruction that activated Idle mode should not write to a Port pin or to the external RAM. 2. Generate a reset. – Note: 10.4 Power-down Mode The Power-down mode places the AT8xC51SND2C in a very low power state. Power-down mode stops the oscillator and freezes all clocks at known states (refer to the Section "Oscillator", page 13). The CPU status prior to entering Power-down mode is preserved, i.e., the program counter, program status word register retain their data for the duration of Power-down mode. In addition, the SFRs and RAM contents are preserved. The status of the Port pins during Powerdown mode is detailed in Table 10-1. Note: VDD may be reduced to as low as VRET during Power-down mode to further reduce power dissipation. Notice, however, that VDD is not reduced until Power-down mode is invoked. 49 4341F–MP3–03/06 10.4.1 Entering Power-down Mode To enter Power-down mode, set PD bit in PCON register. The AT8xC51SND2C enters the Power-down mode upon execution of the instruction that sets PD bit. The instruction that sets PD bit is the last instruction executed. 10.4.2 Exiting Power-down Mode If VDD w as reduced during the Power-down mode, do not exit Power-down mode until VDD is restored to the normal operating level. There are 2 ways to exit the Power-down mode: 1. Generate an enabled external interrupt. – The AT8xC51SND2C provides capability to exit from Power-down using INT0, INT1, and KIN0 inputs. In addition, using KIN input provides high or low level exit capability (see section “Keyboard Interface”, page 204). Hardware clears PD bit in PCON register which starts the oscillator and restores the clocks to the CPU and peripherals. Using INTn input, execution resumes when the input is released (see Figure 10-3) while using KINx input, execution resumes after counting 1024 clock ensuring the oscillator is restarted properly (see Figure 10-4). This behavior is necessary for decoding the key while it is still pressed. In both cases, execution resumes with the interrupt service routine. Upon completion of the interrupt service routine, program execution resumes with the instruction immediately following the instruction that activated Power-down mode. 1. The external interrupt used to exit Power-down mode must be configured as level sensitive (INT0 and INT1 ) and must be assigned the highest priority. In addition, the duration of the interrupt must be long enough to allow the oscillator to stabilize. The execution will only resume when the interrupt is deasserted. 2. Exit from power-down by external interrupt does not affect the SFRs nor the internal RAM content. Note: Figure 10-3. Power-down Exit Waveform Using INT1:0 INT1:0 OSC Active phase Power-down Phase Oscillator Restart Active Phase Figure 10-4. Power-down Exit Waveform Using KIN0 KIN01 OSC Active phase Power-down 1024 clock count Active phase Note: 1. KIN0 can be high or low-level triggered. 2. Generate a reset. 50 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B – A logic high on the RST pin clears PD bit in PCON register directly and asynchronously. This starts the oscillator and restores the clock to the CPU and peripherals. Program execution momentarily resumes with the instruction immediately following the instruction that activated Power-down mode and may continue for a number of clock cycles before the internal reset algorithm takes control. Reset initializes the AT8xC51SND2C and vectors the CPU to address 0000h. 1. During the time that execution resumes, the internal RAM cannot be accessed; however, it is possible for the Port pins to be accessed. To avoid unexpected outputs at the Port pins, the instruction immediately following the instruction that activated the Power-down mode should not write to a Port pin or to the external RAM. 2. Exit from power-down by reset redefines all the SFRs, but does not affect the internal RAM content. Notes: 10.5 Registers Table 10-3. PCON Register PCON (S:87h) – Power Configuration Register 7 SMOD1 6 SMOD0 Bit Mnemonic SMOD1 5 4 3 GF1 2 GF0 1 PD 0 IDL Bit Number 7 Description Serial Port Mode Bit 1 Set to select double baud rate in mode 1,2 or 3. Serial Port Mode Bit 0 Set to select FE bit in SCON register. C lear to select SM0 bit in SCON register. Reserved The value read from these bits is indeterminate. Do not set these bits. General-Purpose Flag 1 One use is to indicate whether an interrupt occurred during normal operation or during Idle mode. General-Purpose Flag 0 One use is to indicate whether an interrupt occurred during normal operation or during Idle mode. Power-Down Mode Bit C leared by hardware when an interrupt or reset occurs. Set to activate the Power-down mode. If IDL and PD are both set, PD takes precedence. Idle Mode Bit C leared by hardware when an interrupt or reset occurs. Set to activate the Idle mode. If IDL and PD are both set, PD takes precedence. 6 SMOD0 5-4 - 3 GF1 2 GF0 1 PD 0 IDL Reset Value = 00XX 0000b 51 4341F–MP3–03/06 11. Timers/Counters The AT8xC51SND2C implement 2 general-purpose, 16-bit Timers/Counters. They are identified as Timer 0 and Timer 1, and can be independently configured to operate in a variety of modes as a Timer or as an event Counter. When operating as a Timer, the Timer/Counter runs for a programmed length of time, then issues an interrupt request. When operating as a Counter, the Timer/Counter counts negative transitions on an external pin. After a preset number of counts, the Counter issues an interrupt request. The various operating modes of each Timer/Counter are described in the following sections. 11.1 Timer/Counter Operations For instance, a basic operation is Timer registers THx and TLx (x = 0, 1) connected in cascade to form a 16-bit Timer. Setting the run control bit (TRx) in TCON register (see Table 11-1) turns the Timer on by allowing the selected input to increment TLx. When TLx overflows it increments THx; when THx overflows it sets the Timer overflow flag (TFx) in TCON register. Setting the TRx does not clear the THx and TLx Timer registers. Timer registers can be accessed to obtain the current count or to enter preset values. They can be read at any time but TRx bit must be cleared to preset their values, otherwise, the behavior of the Timer/Counter is unpredictable. The C/Tx# control bit selects Timer operation or Counter operation by selecting the divideddown peripheral clock or external pin Tx as the source for the counted signal. TRx bit must be cleared when changing the mode of operation, otherwise the behavior of the Timer/Counter is unpredictable. For Timer operation (C/Tx# = 0), the Timer register counts the divided-down peripheral clock. The Timer register is incremented once every peripheral cycle (6 peripheral clock periods). The Timer clock rate is FPER/6, i.e., FOSC/12 in standard mode or FOSC/6 in X2 mode. For Counter operation (C/Tx# = 1), the Timer register counts the negative transitions on the Tx external input pin. The external input is sampled every peripheral cycles. When the sample is high in one cycle and low in the next one, the Counter is incremented. Since it takes 2 cycles (12 peripheral clock periods) to recognize a negative transition, the maximum count rate is FPER/12, i.e., FOSC /24 in standard mode or FOSC/12 in X2 mode. There are no restrictions on the duty cycle of the external input signal, but to ensure that a given level is sampled at least once before it changes, it should be held for at least one full peripheral cycle. 11.2 Timer Clock Controller As shown in Figure 11-1, the Timer 0 (FT0) and Timer 1 (FT1) clocks are derived from either the peripheral clock (FPER) or the oscillator clock (FOSC) depending on the T0X2 and T1X2 bits in CKCON register. These clocks are issued from the Clock Controller block as detailed in Section “Clock Controller”, page 13. When T0X2 or T1X2 bit is set, the Timer 0 or Timer 1 clock frequency is fixed and equal to the oscillator clock frequency divided by 2. When cleared, the Timer clock frequency is equal to the oscillator clock frequency divided by 2 in standard mode or to the oscillator clock frequency in X2 mode. 52 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B Figure 11-1. Timer 0 and Timer 1 Clock Controller and Symbols PER CLOCK OSC CLOCK 0 PER CLOCK OSC CLOCK 0 Timer 0 Clock 1 Timer 1 Clock 1 ÷2 T0X2 CKCON.1 ÷2 T1X2 CKCON.2 TIM0 CLOCK TIM1 CLOCK Timer 0 Clock Symbol Timer 1 Clock Symbol 11.3 Timer 0 Timer 0 functions as either a Timer or event Counter in four modes of operation. Figure 11-2 through Figure 11-8 show the logical configuration of each mode. Timer 0 is controlled by the four lower bits of TMOD register (see Table 11-2) and bits 0, 1, 4 and 5 o f TCON register (see T able 1 1-1 ). TMOD register selects the method of Timer gating ( GATE0), Timer or Counter operation (C/T0#) and mode of operation (M10 and M00). TCON register provides Timer 0 control functions: overflow flag (TF0), run control bit (TR0), interrupt flag (IE0) and interrupt type control bit (IT0). F or normal Timer operation (GATE0 = 0), setting TR0 allows TL0 to be incremented by the selected input. Setting GATE0 and TR0 allows external pin INT0 to control Timer operation. T imer 0 overflow (count rolls over from all 1s to all 0s) sets TF0 flag generating an interrupt request. It is important to stop Timer/Counter before changing mode. 11.3.1 Mode 0 (13-bit Timer) Mode 0 configures Timer 0 as a 13-bit Timer which is set up as an 8-bit Timer (TH0 register) with a modulo 32 prescaler implemented with the lower five bits of TL0 register (see Figure 11-2). The upper three bits of TL0 register are indeterminate and should be ignored. Prescaler overflow increments TH0 register. Figure 11-3 gives the overflow period calculation formula. Figure 11-2. Timer/Counter x (x = 0 or 1) in Mode 0 TIMx CLOCK Tx C/Tx# TMOD Reg INTx GATEx TMOD Reg ÷6 0 1 TLx (5 Bits) THx (8 Bits) Overflow Timer x Interrupt Request TFx TCON reg TRx TCON Reg 53 4341F–MP3–03/06 Figure 11-3. Mode 0 Overflow Period Formula = = TFxPER 6 ⋅ (16384 – (THx, TLx)) FTIMx 11.3.2 Mode 1 (16-bit Timer) Mode 1 configures Timer 0 as a 16-bit Timer with TH0 and TL0 registers connected in cascade (see Figure 11-4). The selected input increments TL0 register. Figure 11-5 gives the overflow period calculation formula when in timer mode. Figure 11-4. Timer/Counter x (x = 0 or 1) in Mode 1 TIMx CLOCK ÷6 0 1 THx (8 bits) TLx (8 bits) Overflow TFx TCON Reg Tx C/Tx# TMOD Reg Timer x Interrupt Request INTx GATEx TMOD Reg TRx TCON Reg Figure 11-5. Mode 1 Overflow Period Formula = TFxPER 6 ⋅ (65536 – (THx, TLx)) FTIMx 11.3.3 Mode 2 (8-bit Timer with Auto-Reload) Mode 2 configures Timer 0 as an 8-bit Timer (TL0 register) that automatically reloads from TH0 register (see Table 11-3). TL0 overflow sets TF0 flag in TCON register and reloads TL0 with the contents of TH0, which is preset by software. When the interrupt request is serviced, hardware clears TF0. The reload leaves TH0 unchanged. The next reload value may be changed at any time by writing it to TH0 register. Figure 11-7 gives the autoreload period calculation formula when in timer mode. Figure 11-6. Timer/Counter x (x = 0 or 1) in Mode 2 TIMx CLOCK ÷6 0 1 TLx (8 bits) Overflow TFx TCON reg Tx C/Tx# TMOD reg Timer x Interrupt Request INTx GATEx TMOD reg TRx TCON reg THx (8 bits) Figure 11-7. Mode 2 Autoreload Period Formula TFxPER 6 ⋅ (256 – THx) FTIMx 54 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B 11.3.4 Mode 3 (2 8-bit Timers) Mode 3 configures Timer 0 such that registers TL0 and TH0 operate as separate 8-bit Timers (see Figure 11-8). This mode is provided for applications requiring an additional 8-bit Timer or C ounter. TL0 uses the Timer 0 control bits C/T0# and GATE0 in TMOD register, and TR0 and TF0 in TCON register in the normal manner. TH0 is locked into a Timer function (counting FTF1/6) and takes over use of the Timer 1 interrupt (TF1) and run control (TR1) bits. Thus, operation of Timer 1 is restricted when Timer 0 is in mode 3. Figure 11-7 gives the autoreload period calculation formulas for both TF0 and TF1 flags. Figure 11-8. Timer/Counter 0 in Mode 3: 2 8-bit Counters TIM0 CLOCK ÷6 0 1 TL0 (8 bits) Overflow TF0 TCON.5 T0 C/T0# TMOD.2 Timer 0 Interrupt Request INT0 GATE0 TMOD.3 TR0 TCON.4 TIM0 CLOCK ÷6 TH0 (8 bits) TR1 TCON.6 Overflow TF1 TCON.7 Timer 1 Interrupt Request Figure 11-9. Mode 3 Overflow Period Formula = = TF0PER 6 ⋅ (256 – TL0) FTIM0 TF1PER 6 ⋅ (256 – TH0) FTIM0 11.4 Timer 1 Timer 1 is identical to Timer 0 except for Mode 3 which is a hold-count mode. The following comments help to understand the differences: • Timer 1 functions as either a Timer or event Counter in three modes of operation. Figure 112 through Figure 11-6 show the logical configuration for modes 0, 1, and 2. Timer 1’s mode 3 is a hold-count mode. Timer 1 is controlled by the four high-order bits of TMOD register (see Figure 11-2) and bits 2, 3, 6 and 7 of TCON register (see Figure 11-1). TMOD register selects the method of Timer gating (GATE1), Timer or Counter operation (C/T1#) and mode of operation (M11 and M01). TCON register provides Timer 1 control functions: overflow flag (TF1), run control bit (TR1), interrupt flag (IE1) and interrupt type control bit (IT1). Timer 1 can serve as the Baud Rate Generator for the Serial Port. Mode 2 is best suited for this purpose. For normal Timer operation (GATE1 = 0), setting TR1 allows TL1 to be incremented by the selected input. Setting GATE1 and TR1 allows external pin INT1 to control Timer operation. Timer 1 overflow (count rolls over from all 1s to all 0s) sets the TF1 flag generating an interrupt request. • • • • 55 4341F–MP3–03/06 • When Timer 0 is in mode 3, it uses Timer 1’s overflow flag (TF1) and run control bit (TR1). For this situation, use Timer 1 only for applications that do not require an interrupt (such as a Baud Rate Generator for the Serial Port) and switch Timer 1 in and out of mode 3 to turn it off and on. It is important to stop the Timer/Counter before changing modes. • 11.4.1 Mode 0 (13-bit Timer) Mode 0 configures Timer 1 as a 13-bit Timer, which is set up as an 8-bit Timer (TH1 register) with a modulo-32 prescaler implemented with the lower 5 bits of the TL1 register (see Figure 112). The upper 3 bits of TL1 register are ignored. Prescaler overflow increments TH1 register. 11.4.2 Mode 1 (16-bit Timer) Mode 1 configures Timer 1 as a 16-bit Timer with TH1 and TL1 registers connected in cascade (see Figure 11-4). The selected input increments TL1 register. 11.4.3 Mode 2 (8-bit Timer with Auto-Reload) Mode 2 configures Timer 1 as an 8-bit Timer (TL1 register) with automatic reload from TH1 register on overflow (see Figure 1 1-6). TL1 overflow sets TF1 flag in TCON register and reloads TL1 with the contents of TH1, which is preset by software. The reload leaves TH1 unchanged. 11.4.4 Mode 3 (Halt) Placing Timer 1 in mode 3 causes it to halt and hold its count. This can be used to halt Timer 1 when TR1 run control bit is not available i.e. when Timer 0 is in mode 3. 11.5 Interrupt Each Timer handles one interrupt source that is the timer overflow flag TF0 or TF1. This flag is set every time an overflow occurs. Flags are cleared when vectoring to the Timer interrupt routine. Interrupts are enabled by setting E Tx b it in IEN0 register. This assumes interrupts are globally enabled by setting EA bit in IEN0 register. Figure 11-10. Timer Interrupt System TF0 TCON.5 Timer 0 Interrupt Request ET0 IEN0.1 TF1 TCON.7 Timer 1 Interrupt Request ET1 IEN0.3 56 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B 11.6 Registers Table 11-1. TCON Register TCON (S:88h) – Timer/Counter Control Register 7 TF1 6 TR1 Bit Mnemonic 5 TF0 4 TR0 3 IE1 2 IT1 1 IE0 0 IT0 Bit Number Description Timer 1 Overflow Flag C leared by hardware when processor vectors to interrupt routine. Set by hardware on Timer/Counter overflow, when Timer 1 register overflows. Timer 1 Run Control Bit C lear to turn off Timer/Counter 1. Set to turn on Timer/Counter 1. Timer 0 Overflow Flag C leared by hardware when processor vectors to interrupt routine. Set by hardware on Timer/Counter overflow, when Timer 0 register overflows. Timer 0 Run Control Bit C lear to turn off Timer/Counter 0. Set to turn on Timer/Counter 0. Interrupt 1 Edge Flag C leared by hardware when interrupt is processed if edge-triggered (see IT1). Set by hardware when external interrupt is detected on INT1 pin. Interrupt 1 Type Control Bit C lear to select low level active (level triggered) for external interrupt 1 (INT1). Set to select falling edge active (edge triggered) for external interrupt 1. Interrupt 0 Edge Flag C leared by hardware when interrupt is processed if edge-triggered (see IT0). Set by hardware when external interrupt is detected on INT0 pin. Interrupt 0 Type Control Bit C lear to select low level active (level triggered) for external interrupt 0 (INT0). Set to select falling edge active (edge triggered) for external interrupt 0. 7 TF1 6 TR1 5 TF0 4 TR0 3 IE1 2 IT1 1 IE0 0 IT0 Reset Value = 0000 0000b 57 4341F–MP3–03/06 7 GATE1 Bit Number 6 C/T1# Bit Mnemonic 5 M11 4 M01 3 GATE0 2 C/T0# 1 M10 0 M00 Description Timer 1 Gating Control Bit C lear to enable Timer 1 whenever TR1 bit is set. S et to enable Timer 1 only while INT1 pin is high and TR1 bit is set. Timer 1 Counter/Timer Select Bit C lear for Timer operation: Timer 1 counts the divided-down system clock. S et for Counter operation: Timer 1 counts negative transitions on external pin T1. Timer 1 Mode Select Bits M11 M01 Operating mode 0 0 Mode 0: 8-bit Timer/Counter (TH1) with 5-bit prescaler (TL1). 0 1 Mode 1: 16-bit Timer/Counter. 1 0 Mode 2: 8-bit auto-reload Timer/Counter (TL1).(1) 1 1 Mode 3: Timer 1 halted. Retains count. Timer 0 Gating Control Bit C lear to enable Timer 0 whenever TR0 bit is set. Set to enable Timer/Counter 0 only while INT0 pin is high and TR0 bit is set. Timer 0 Counter/Timer Select Bit C lear for Timer operation: Timer 0 counts the divided-down system clock. S et for Counter operation: Timer 0 counts negative transitions on external pin T0. Timer 0 Mode Select Bit M10 M00 Operating mode 0 0 Mode 0: 8-bit Timer/Counter (TH0) with 5-bit prescaler (TL0). 0 1 Mode 1: 16-bit Timer/Counter. 1 0 Mode 2: 8-bit auto-reload Timer/Counter (TL0).(2) 1 1Mode 3: TL0 is an 8-bit Timer/Counter. TH0 is an 8-bit Timer using Timer 1’s TR0 and TF0 bits. 7 GATE1 6 C/T1# 5 M11 4 M01 3 GATE0 2 C/T0# 1 M10 0 M00 Notes: 1. Reloaded from TH1 at overflow. 2. Reloaded from TH0 at overflow. Reset Value = 0000 0000b Table 11-2. TH0 Register TH0 (S:8Ch) – Timer 0 High Byte Register 7 6 Bit Mnemonic 5 4 3 2 1 0 - Bit Number 7:0 Description High Byte of Timer 0 Reset Value = 0000 0000b Table 11-3. TL0 Register 58 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B TL0 (S:8Ah) – Timer 0 Low Byte Register 7 6 Bit Mnemonic 5 4 3 2 1 0 - Bit Number 7:0 Description Low Byte of Timer 0 Reset Value = 0000 0000b Table 11-4. TH1 Register TH1 (S:8Dh) – Timer 1 High Byte Register 7 6 Bit Mnemonic 5 4 3 2 1 0 - Bit Number 7:0 Description High Byte of Timer 1 Reset Value = 0000 0000b Table 11-5. TL1 Register TL1 (S:8Bh) – Timer 1 Low Byte Register 7 6 Bit Mnemonic 5 4 3 2 1 0 - Bit Number 7:0 Description Low Byte of Timer 1 Reset Value = 0000 0000b 59 4341F–MP3–03/06 12. Watchdog Timer The AT8xC51SND2C implement a hardware Watchdog Timer (WDT) that automatically resets the chip if it is allowed to time out. The WDT provides a means of recovering from routines that do not complete successfully due to software or hardware malfunctions. 12.1 Description The WDT consists of a 14-bit prescaler followed by a 7-bit programmable counter. As shown in Figure 12-1, the 14-bit prescaler is fed by the WDT clock detailed in Section “Watchdog Clock Controller”, page 60. The Watchdog Timer Reset register (WDTRST, see Table 12-2) provides control access to the W DT, while the Watchdog Timer Program register (WDTPRG, see Figure 12-4) provides timeout period programming. Three operations control the WDT: • • • Chip reset clears and disables the WDT. Programming the time-out value to the WDTPRG register. Writing a specific 2-Byte sequence to the WDTRST register clears and enables the WDT. Figure 12-1. WDT Block Diagram WDT CLOCK ÷6 14-bit Prescaler RST 7-bit Counter OV RST SET To internal reset WTO2:0 1Eh-E1h Decoder System Reset RST EN WDTPRG.2:0 MATCH OSC CLOCK Pulse Generator RST WDTRST 12.2 Watchdog Clock Controller As shown in Figure 12-2 the WDT clock (FWDT ) is derived from either the peripheral clock (FPER) or the oscillator clock (FOSC) depending on the WTX2 bit in CKCON register. These clocks are issued from the Clock Controller block as detailed in Section "Clock Controller", page 13. When WTX2 bit is set, the WDT clock frequency is fixed and equal to the oscillator clock frequency divided by 2. When cleared, the WDT clock frequency is equal to the oscillator clock frequency divided by 2 in standard mode or to the oscillator clock frequency in X2 mode. Figure 12-2. WDT Clock Controller and Symbol PER CLOCK OSC CLOCK 0 WDT CLOCK WDT Clock 1 ÷2 WTX2 CKCON.6 WDT Clock Symbol 60 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B 12.3 Watchdog Operation After reset, the WDT is disabled. The WDT is enabled by writing the sequence 1Eh and E1h into the WDTRST register. As soon as it is enabled, there is no way except the chip reset to disable it. If it is not cleared using the previous sequence, the WDT overflows and forces a chip reset. This overflow generates a high level 96 oscillator periods pulse on the RST pin to globally reset the application (refer to Section “Power Management”, page 47). The WDT time-out period can be adjusted using WTO2:0 bits located in the WDTPRG register accordingly to the formula shown in Figure 12-3. In this formula, WTOval represents the decimal value of WTO2:0 bits. Table 12-1 reports the time-out period depending on the WDT frequency. Figure 12-3. WDT Time-Out Formula WDTTO (( 6⋅ = 214 ⋅ 2WTOval) – 1) FWDT Table 12-1. WDT Time-Out Computation FWDT (ms) 6 MHz(1) 16.38 32.77 65.54 131.07 262.14 524.29 1049 2097 8 MHz (1) 12.28 24.57 49.14 98.28 196.56 393.1 786.24 1572 10 MHz(1) 9.83 19.66 39.32 78.64 157.29 314.57 629.15 1258 12 MHz(2) 8.19 16.38 32.77 65.54 131.07 262.14 524.29 1049 16 MHz(2) 6.14 12.28 24.57 49.14 98.28 196.56 393.12 786.24 20 MHz(2) 4.92 9.83 19.66 39.32 78.64 157.29 314.57 629.15 WTO2 0 0 0 0 1 1 1 1 WTO1 0 0 1 1 0 0 1 1 WTO0 0 1 0 1 0 1 0 1 Notes: 1. These frequencies are achieved in X1 mode or in X2 mode when WTX2 = 1: FWDT = F OSC ÷ 2. 2. These frequencies are achieved in X2 mode when WTX2 = 0: F WDT = FOSC . 12.3.1 WDT Behavior during Idle and Power-down Modes Operation of the WDT during power reduction modes deserves special attention. The WDT continues to count while the AT8xC51SND2C is in Idle mode. This means that you must dedicate some internal or external hardware to service the WDT during Idle mode. One approach is to use a peripheral Timer to generate an interrupt request when the Timer overflows. The interrupt service routine then clears the WDT, reloads the peripheral Timer for the next service period and puts the AT8xC51SND2C back into Idle mode. The Power-down mode stops all phase clocks. This causes the WDT to stop counting and to hold its count. The WDT resumes counting from where it left off if the Power-down mode is terminated by INT0, INT1 or keyboard interrupt. To ensure that the WDT does not overflow shortly after exiting the Power-down mode, it is recommended to clear the WDT just before entering Power-down mode. The WDT is cleared and disabled if the Power-down mode is terminated by a reset. 61 4341F–MP3–03/06 12.4 Registers Table 12-2. WDTRST Register WDTRST (S:A6h Write only) – Watchdog Timer Reset Register 7 6 Bit Mnemonic 5 4 3 2 1 0 - Bit Number 7-0 Description Watchdog Control Value Reset Value = XXXX XXXXb Figure 12-4. WDTPRG Register WDTPRG (S:A7h) – Watchdog Timer Program Register 7 6 Bit Mnemonic 5 4 3 2 WTO2 1 WTO1 0 WTO0 Bit Number 7-3 Description Reserved The value read from these bits is indeterminate. Do not set these bits. Watchdog Timer Time-Out Selection Bits R efer to Table 12-1 for time-out periods. 2-0 WTO2:0 Reset Value = XXXX X000b 62 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B 13. MP3 Decoder The AT8xC51SND2C implement a MPEG I/II audio layer 3 decoder better known as MP3 decoder. In MPEG I (ISO 11172-3) three layers of compression have been standardized supporting three sampling frequencies: 48, 44.1, and 32 kHz. Among these layers, layer 3 allows highest compression rate of about 12:1 while still maintaining CD audio quality. For example, 3 minutes of CD audio (16-bit PCM, 44.1 kHz) data, which needs about 32M bytes of storage, can be encoded into only 2.7M bytes of MPEG I audio layer 3 data. In MPEG II (ISO 13818-3), three additional sampling frequencies: 24, 22.05, and 16 kHz are supported for low bit rates applications. The AT8xC51SND2C can decode in real-time the MPEG I audio layer 3 encoded data into a PCM audio data, and also supports MPEG II audio layer 3 additional frequencies. Additional features are supported by the AT8xC51SND2C MP3 decoder such as volume control, bass, medium, and treble controls, bass boost effect and ancillary data extraction. 13.1 13.1.1 Decoder Description The C51 core interfaces to the MP3 decoder through nine special function registers: MP3CON, the MP3 Control register (see Table 13-5); MP3STA, the MP3 Status register (see Table 13-6); M P3DAT, the MP3 Data register (see Table 1 3-7); MP3ANC, the Ancillary Data register (see T able 13-9); MP3VOL and MP3VOR, the MP3 Volume Left and Right Control registers (see Table 13-10 and Table 13-11); MP3BAS, MP3MED, and MP3TRE, the MP3 Bass, Medium, and Treble Control registers (see Table 13-12, Table 13-13, and Table 13-14); and MPCLK, the MP3 Clock Divider register (see Table 13-15). Figure 13-1 shows the MP3 decoder block diagram. Figure 13-1. MP3 Decoder Block Diagram Audio Data From C51 8 1K Bytes Frame Buffer MP3DAT Header Checker Huffman Decoder Dequantizer Stereo Processor Side Information MPxREQ MP3 CLOCK MP3STA1.n ERRxxx MPFS1:0 MPVER MP3STA.5:3 MP3STA.2:1 MP3STA.0 Ancillary Buffer MP3ANC MPEN MP3CON.7 Anti-Aliasing IMDCT Sub-band Synthesis 16 Decoded Data To Audio Interface MPBBST MP3CON.6 MP3VOL MP3VOR MP3BAS MP3MED MP3TRE 63 4341F–MP3–03/06 13.1.2 MP3 Data The MP3 decoder does not start any frame decoding before having a complete frame in its input buffer(1). In order to manage the load of MP3 data in the frame buffer, a hardware handshake consisting of data request and data acknowledgment is implemented. Each time the MP3 decoder needs MP3 data, it sets the MPREQ, MPFREQ and MPBREQ flags respectively in MP3STA and MP3STA1 registers. MPREQ flag can generate an interrupt if enabled as explained in Section “Interrupt”. The CPU must then load data in the buffer by writing it through M P3DAT register thus acknowledging the previous request. As shown in F igure 1 3-2 , the M PFREQ flag remains set while data (i.e a frame) is requested by the decoder. It is cleared when no more data is requested and set again when new data are requested. MPBREQ flag toggles at every Byte writing. Note: 1. The first request after enable, consists in 1024 Bytes of data to fill in the input buffer. Figure 13-2. Data Timing Diagram MPREQ Flag MPFREQ Flag MPBREQ Flag Write to MP3DAT Cleared when Reading MP3STA 13.1.3 MP3 Clock The MP3 decoder clock is generated by division of the PLL clock. The division factor is given by MPCD4:0 bits in MP3CLK register. Figure 13-3 shows the MP3 decoder clock generator and its c alculation formula. The MP3 decoder clock frequency depends only on the incoming MP3 frames. Figure 13-3. MP3 Clock Generator and Symbol MP3CLK PLL CLOCK MPCD4:0 MP3 Decoder Clock MP3 CLOCK MP3 Clock Symbol PL Lclk M P3 clk = ---------------------------MPCD + 1 As soon as the frame header has been decoded and the MPEG version extracted, the minimum MP3 input frequency must be programmed according to Table 13-1. Table 13-1. MP3 Clock Frequency MPEG Version I II Minimum MP3 Clock (MHz) 21 10.5 64 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B 13.2 13.2.1 Audio Controls Volume Control The MP3 decoder implements volume control on both right and left channels. The MP3VOR and MP3VOL registers allow a 32-step volume control according to Table 13-2. Table 13-2. Volume Control VOL4:0 or VOR4:0 00000 00001 00010 11110 11111 Volume Gain (dB) Mute -33 -27 -1.5 0 13.2.2 Equalization Control Sound can be adjusted using a 3-band equalizer: a bass band under 750 Hz, a medium band from 750 Hz to 3300 Hz and a treble band over 3300 Hz. The MP3BAS, MP3MED, and MP3TRE registers allow a 32-step gain control in each band according to Table 13-3. Table 13-3. Bass, Medium, Treble Control Gain (dB) -∞ -14 -10 +1 +1.5 BAS4:0 or MED4:0 or TRE4:0 00000 00001 00010 11110 11111 13.2.3 Special Effect The MPBBST bit in MP3CON register allows enabling of a bass boost effect with the following characteristics: gain increase of +9 dB in the frequency under 375 Hz. 13.3 Decoding Errors The three different errors that can appear during frame processing are detailed in the following sections. All these errors can trigger an interrupt as explained in Section "Interrupt", page 66. 13.3.1 Layer Error The ERRSYN flag in MP3STA is set when a non-supported layer is decoded in the header of the frame that has been sent to the decoder. 13.3.2 Synchronization Error The ERRSYN flag in MP3STA is set when no synchronization pattern is found in the data that have been sent to the decoder. 65 4341F–MP3–03/06 13.3.3 CRC Error When the CRC of a frame does not match the one calculated, the flag ERRCRC in MP3STA is set. In this case, depending on the CRCEN bit in MP3CON, the frame is played or rejected. In both cases, noise may appear at audio output. 13.4 Frame Information The MP3 frame header contains information on the audio data contained in the frame. These informations is made available in the MP3STA register for you information. MPVER and MPFS1:0 bits allow decoding of the sampling frequency according to Table 1 3-4. MPVER bit gives the MPEG version (2 or 1). Table 13-4. MPVER 0 0 0 0 1 1 1 1 MP3 Frame Frequency Sampling MPFS1 0 0 1 1 0 0 1 1 MPFS0 0 1 0 1 0 1 0 1 Fs (kHz) 22.05 (MPEG II) 24 (MPEG II) 16 (MPEG II) Reserved 44.1 (MPEG I) 48 (MPEG I) 32 (MPEG I) Reserved 13.5 Ancillary Data MP3 frames also contain data bits called ancillary data. These data are made available in the MP3ANC register for each frame. As shown in Figure 13-4, the ancillary data are available by Bytes when MPANC flag in MP3STA register is set. MPANC flag is set when the ancillary buffer is not empty (at least one ancillary data is available) and is cleared only when there is no more ancillary data in the buffer. This flag can generate an interrupt as explained in S ection "Interrupt", page 66. When set, software must read all Bytes to empty the ancillary buffer. Figure 13-4. Ancillary Data Block Diagram Ancillary Data To C51 8 MP3ANC 8 7-Byte Ancillary Buffer MPANC MP3STA.7 13.6 13.6.1 Interrupt Description As shown in Figure 13-5, the MP3 decoder implements five interrupt sources reported in ERR CRC, ERRSYN, ERRLAY, MPREQ, and MPANC flags in MP3STA register. All these sources are maskable separately using MSKCRC, MSKSYN, MSKLAY, MSKREQ, and MSKANC mask bits respectively in MP3CON register. The MP3 interrupt is enabled by setting EMP3 bit in IEN0 register. This assumes interrupts are globally enabled by setting EA bit in IEN0 register. 66 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B All interrupt flags but MPANC are cleared when reading MP3STA register. The MPANC flag is cleared by hardware when the ancillary buffer becomes empty.. Figure 13-5. MP3 Decoder Interrupt System MPANC MP3STA.7 MSKANC MPREQ MP3STA.6 MP3CON.4 MSKREQ ERRLAY MP3STA.5 MP3CON.3 MP3 Decoder Interrupt Request MSKLAY EMP3 IEN0.5 ERRSYN MP3STA.4 MP3CON.2 MSKSYN ERRCRC MP3STA.3 MP3CON.1 MSKCRC MP3CON.0 67 4341F–MP3–03/06 13.6.2 Management Reading the MP3STA register automatically clears the interrupt flags (acknowledgment) except the MPANC flags. This implies that register content must be saved and tested, interrupt flag by interrupt flag to be sure not to forget any interrupts. Figure 13-6. MP3 Interrupt Service Routine Flow MP3 Decoder ISR Read MP3STA Data Request? MPFREQ = 1? Data Request Handler Ancillary Data?(1) MPANC = 1? Write MP3 Data to MP3DAT Ancillary Data Handler Sync Error?(1) ERRSYN = 1? Read ANN2:0 Ancillary Bytes From MP3ANC Synchro Error Handler Layer Error?(1) ERRSYN = 1? Reload MP3 Frame Through MP3DAT Layer Error Handler CRC Error Handler Load New MP3 Frame Through MP3DAT Note: 1. Test these bits only if needed (unmasked interrupt). 68 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B 13.7 Registers Table 13-5. 7 MPEN MP3CON Register MP3CON (S:AAh) – MP3 Decoder Control Register 6 MPBBST Bit Mnemonic 5 CRCEN 4 MSKANC 3 MSKREQ 2 MSKLAY 1 MSKSYN 0 MSKCRC Bit Number Description MP3 Decoder Enable Bit Set to enable the MP3 decoder. C lear to disable the MP3 decoder. Bass Boost Bit Set to enable the bass boost sound effect. C lear to disable the bass boost sound effect. CRC Check Enable Bit S et to enable processing of frame that contains CRC error. Frame is played whatever the error. C lear to disable processing of frame that contains CRC error. Frame is skipped. MPANC Flag Mask Bit Set to prevent the MPANC flag from generating a MP3 interrupt. C lear to allow the MPANC flag to generate a MP3 interrupt. MPREQ Flag Mask Bit Set to prevent the MPREQ flag from generating a MP3 interrupt. C lear to allow the MPREQ flag to generate a MP3 interrupt. ERRLAY Flag Mask Bit Set to prevent the ERRLAY flag from generating a MP3 interrupt. C lear to allow the ERRLAY flag to generate a MP3 interrupt. ERRSYN Flag Mask Bit Set to prevent the ERRSYN flag from generating a MP3 interrupt. C lear to allow the ERRSYN flag to generate a MP3 interrupt. ERRCRC Flag Mask Bit Set to prevent the ERRCRC flag from generating a MP3 interrupt. C lear to allow the ERRCRC flag to generate a MP3 interrupt. 7 MPEN 6 MPBBST 5 CRCEN 4 MSKANC 3 MSKREQ 2 MSKLAY 1 MSKSYN 0 MSKCRC Reset Value = 0011 1111b 69 4341F–MP3–03/06 Table 13-6. 7 MPANC MP3STA Register MP3STA (S:C8h Read Only) – MP3 Decoder Status Register 6 MPREQ Bit Mnemonic 5 ERRLAY 4 ERRSYN 3 ERRCRC 2 MPFS1 1 MPFS0 0 MPVER Bit Number Description Ancillary Data Available Flag Set by hardware as soon as one ancillary data is available (buffer not empty). C leared by hardware when no more ancillary data is available (buffer empty). MP3 Data Request Flag Set by hardware when MP3 decoder request data. C leared when reading MP3STA. Invalid Layer Error Flag Set by hardware when an invalid layer is encountered. C leared when reading MP3STA. Frame Synchronization Error Flag Set by hardware when no synchronization pattern is encountered in a frame. C leared when reading MP3STA. CRC Error Flag Set by hardware when a frame handling CRC is corrupted. C leared when reading MP3STA. Frequency Sampling Bits R efer to Table 13-4 for bits description. MPEG Version Bit Set by the MP3 decoder when the loaded frame is a MPEG I frame. C leared by the MP3 decoder when the loaded frame is a MPEG II frame. 7 MPANC 6 MPREQ 5 ERRLAY 4 ERRSYN 3 ERRCRC 2-1 MPFS1:0 0 MPVER Reset Value = 0000 0001b Table 13-7. 7 MPD7 MP3DAT Register MP3DAT (S:ACh) – MP3 Data Register 6 MPD6 Bit Mnemonic MPD7:0 5 MPD5 4 MPD4 3 MPD3 2 MPD2 1 MPD1 0 MPD0 Bit Number 7-0 Description Input Stream Data Buffer 8-bit MP3 stream data input buffer. Reset Value = 0000 0000b 70 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B Table 13-8. 7 - MP3STA1 Register MP3STA1 (S:AFh) – MP3 Decoder Status Register 1 6 Bit Mnemonic 5 4 MPFREQ 3 MPFREQ 2 1 0 - Bit Number 7-5 Description Reserved The value read from these bits is always 0. Do not set these bits. MP3 Frame Data Request Flag Set by hardware when MP3 decoder request data. C leared when MP3 decoder no more request data . MP3 Byte Data Request Flag Set by hardware when MP3 decoder request data. C leared when writing to MP3DAT. Reserved The value read from these bits is always 0. Do not set these bits. 4 MPFREQ 3 MPBREQ 2-0 - Reset Value = 0001 0001b Table 13-9. 7 AND7 MP3ANC Register MP3ANC (S:ADh Read Only) – MP3 Ancillary Data Register 6 AND6 Bit Mnemonic AND7:0 5 AND5 4 AND4 3 AND3 2 AND2 1 AND1 0 AND0 Bit Number 7-0 Description Ancillary Data Buffer MP3 ancillary data Byte buffer. Reset Value = 0000 0000b Table 13-10. MP3VOL Register MP3VOL (S:9Eh) – MP3 Volume Left Control Register 7 6 Bit Mnemonic 5 4 VOL4 3 VOL3 2 VOL2 1 VOL1 0 VOL0 Bit Number 7-5 Description Reserved The value read from these bits is always 0. Do not set these bits. Volume Left Value R efer to Table 13-2 for the left channel volume control description. 4-0 VOL4:0 Reset Value = 0000 0000b 71 4341F–MP3–03/06 Table 13-11. MP3VOR Register MP3VOR (S:9Fh) – MP3 Volume Right Control Register 7 6 Bit Mnemonic 5 4 VOR4 3 VOR3 2 VOR2 1 VOR1 0 VOR0 Bit Number 7-5 Description Reserved The value read from these bits is always 0. Do not set these bits. Volume Right Value R efer to Table 13-2 for the right channel volume control description. 4-0 VOR4:0 Reset Value = 0000 0000b Table 13-12. MP3BAS Register MP3BAS (S:B4h) – MP3 Bass Control Register 7 6 Bit Mnemonic 5 4 BAS4 3 BAS3 2 BAS2 1 BAS1 0 BAS0 Bit Number 7-5 Description Reserved The value read from these bits is always 0. Do not set these bits. Bass Gain Value R efer to Table 13-3 for the bass control description. 4-0 BAS4:0 Reset Value = 0000 0000b Table 13-13. MP3MED Register MP3MED (S:B5h) – MP3 Medium Control Register 7 6 Bit Mnemonic 5 4 MED4 3 MED3 2 MED2 1 MED1 0 MED0 Bit Number 7-5 Description Reserved The value read from these bits is always 0. Do not set these bits. Medium Gain Value R efer to Table 13-3 for the medium control description. 4-0 MED4:0 Reset Value = 0000 0000b 72 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B Table 13-14. MP3TRE Register MP3TRE (S:B6h) – MP3 Treble Control Register 7 6 Bit Mnemonic 5 4 TRE4 3 TRE3 2 TRE2 1 TRE1 0 TRE0 Bit Number 7-5 Description Reserved The value read from these bits is always 0. Do not set these bits. Treble Gain Value R efer to Table 13-3 for the treble control description. 4-0 TRE4:0 Reset Value = 0000 0000b Table 13-15. MP3CLK Register MP3CLK (S:EBh) – MP3 Clock Divider Register 7 6 Bit Mnemonic 5 4 MPCD4 3 MPCD3 2 MPCD2 1 MPCD1 0 MPCD0 Bit Number 7-5 Description Reserved The value read from these bits is always 0. Do not set these bits. MP3 Decoder Clock Divider 5-bit divider for MP3 decoder clock generation. 4-0 MPCD4:0 Reset Value = 0000 0000b 73 4341F–MP3–03/06 14. Audio Output Interface The AT8xC51SND2C implement an audio output interface allowing the audio bitstream to be output in various formats. It is compatible with right and left justification PCM and I2S formats and thanks to the on-chip PLL (see S ection “Clock Controller”, page 13) allows connection of almost all of the commercial audio DAC families available on the market. The audio bitstream can be from 2 different types: • • The MP3 decoded bitstream coming from the MP3 decoder for playing songs. The audio bitstream coming from the MCU for outputting voice or sounds. 14.1 Description The C51 core interfaces to the audio interface through five special function registers: AUDCON0 and AUDCON1, the Audio Control registers (see T able 14-3 and Table 14-4); AUDSTA, the Audio Status register (see Table 14-5); AUDDAT, the Audio Data register (see Table 14-6); and AUDCLK, the Audio Clock Divider register (see Table 14-7). Figure 1 4-1 s hows the audio interface block diagram, blocks are detailed in the following sections. Figure 14-1. Audio Interface Block Diagram SCLK AUD CLOCK DCLK Clock Generator 0 AUDEN AUDCON1.0 DSEL 1 HLR Data Ready Audio Data From MP3 Decoder Sample Request To MP3 Decoder AUDCON0.0 DSIZ AUDCON0.1 POL AUDCON0.2 16 MP3 Buffer 16 16 0 1 Data Converter DOUT DRQEN AUDCON1.6 JUST4:0 SRC AUDCON1.7 AUDCON0.7:3 SREQ Audio Data From C51 8 Audio Buffer AUDDAT AUDSTA.7 UDRN AUDSTA.6 To DAC AUBUSY DUP1:0 AUDCON1.2:1 AUDSTA.5 74 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B 14.2 Clock Generator The audio interface clock is generated by division of the PLL clock. The division factor is given by AUCD4:0 bits in CLKAUD register. Figure 14-2 shows the audio interface clock generator and its calculation formula. The audio interface clock frequency depends on the incoming MP3 frames and the audio DAC used. Figure 14-2. Audio Clock Generator and Symbol AUDCLK PLL CLOCK AUD CLOCK AUCD4:0 Audio Interface Clock PLLclk AUDclk = --------------------------AU C D + 1 Audio Clock Symbol As soon as audio interface is enabled by setting AUDEN bit in AUDCON1 register, the master clock generated by the PLL is output on the SCLK pin which is the DAC system clock. This clock is output at 256 or 384 times the sampling frequency depending on the DAC capabilities. HLR bit in AUDCON0 register must be set according to this rate for properly generating the audio bit clock on the DCLK pin and the word selection clock on the DSEL pin. These clocks are not generated when no data is available at the data converter input. For DAC compatibility, the bit clock frequency is programmable for outputting 16 bits or 32 bits per channel using the DSIZ bit in AUDCON0 register (see Section "Data Converter", page 75), a nd the word selection signal is programmable for outputting left channel on low or high level according to POL bit in AUDCON0 register as shown in Figure 14-3. Figure 14-3. DSEL Output Polarity POL = 0 POL = 1 Left Channel Left Channel Right Channel Right Channel 14.3 Data Converter The data converter block converts the audio stream input from the 16-bit parallel format to a serial format. For accepting all PCM formats and I2S format, JUST4:0 bits in AUDCON0 register are used to shift the data output point. As shown in Figure 14-4, these bits allow MSB justification by setting JUST4:0 = 00000, LSB justification by setting JUST4:0 = 10000, I2S justification by setting JUST4:0 = 00001, and more than 16-bit LSB justification by filling the low significant bits with logic 0. Table 14-1. DAC Format Programing Examples Dac Format 16-bit I2S > 16-bit I S 16-bit PCM 18-bit PCM LSB justified 20-bit PCM LSB justified 20-bit PCM MSB justified 2 POL 0 0 1 1 1 1 DSIZ 0 1 0 1 1 1 JUST4:0 00001 00001 00000 01110 01100 00000 75 4341F–MP3–03/06 Figure 14-4. Audio Output Format DSEL DCLK DOUT 1 2 3 Left Channel 13 14 15 16 1 2 3 Right Channel 13 14 15 16 LSB MSB B14 B1 LSB MSB B14 B1 I2S Format with DSIZ = 0 and JUST4:0 = 00001. DSEL DCLK DOUT 1 2 3 Left Channel 17 18 32 1 2 3 Right Channel 17 18 32 MSB B14 LSB MSB B14 LSB I2S Format with DSIZ = 1 and JUST4:0 = 00001. DSEL DCLK DOUT 1 2 3 Left Channel 13 14 15 16 1 2 3 Right Channel 13 14 15 16 MSB B14 B1 LSB MSB B15 B1 LSB MSB/LSB Justified Format with DSIZ = 0 and JUST4:0 = 00000. DSEL DCLK DOUT 1 Left Channel 16 17 18 31 32 1 Right Channel 16 17 18 31 32 MSB B14 B1 LSB MSB B14 B1 LSB 16-bit LSB Justified Format with DSIZ = 1 and JUST4:0 = 10000. DSEL DCLK DOUT 1 Left Channel 15 16 30 31 32 1 Right Channel 15 16 30 31 32 MSB B16 B2 B1 LSB MSB B16 B2 B1 LSB 18-bit LSB Justified Format with DSIZ = 1 and JUST4:0 = 01110. The data converter receives its audio stream from 2 sources selected by the SRC bit in AUDCON1 register. When cleared, the audio stream comes from the MP3 decoder (see Section “MP3 Decoder”, page 63) for song playing. When set, the audio stream is coming from the C51 core for voice or sound playing. As soon as first audio data is input to the data converter, it enables the clock generator for generating the bit and word clocks. 14.4 Audio Buffer In voice or sound playing mode, the audio stream comes from the C51 core through an audio buffer. The data is in 8-bit format and is sampled at 8 kHz. The audio buffer adapts the sample format and rate. The sample format is extended to 16 bits by filling the LSB to 00h. Rate is adapted to the DAC rate by duplicating the data using DUP1:0 bits in AUDCON1 register according to Table 14-2. The audio buffer interfaces to the C51 core through three flags: the sample request flag (SREQ in AUDSTA register), the under-run flag (UNDR in AUDSTA register) and the busy flag (AUBUSY in AUDSTA register). SREQ and UNDR can generate an interrupt request as explained in Section "Interrupt Request", page 77. The buffer size is 8 Bytes large. SREQ is set w hen the samples number switches from 4 to 3 and reset when the samples number switches from 4 to 5; UNDR is set when the buffer becomes empty signaling that the audio interface ran out of samples; and AUBUSY is set when the buffer is full. 76 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B Table 14-2. DUP1 0 0 1 1 Sample Duplication Factor DUP0 0 1 0 1 Factor No sample duplication, DAC rate = 8 kHz (C51 rate). One sample duplication, DAC rate = 16 kHz (2 x C51 rate). 2 samples duplication, DAC rate = 32 kHz (4 x C51 rate). Three samples duplication, DAC rate = 48 kHz (6 x C51 rate). 14.5 MP3 Buffer In song playing mode, the audio stream comes from the MP3 decoder through a buffer. The MP3 buffer is used to store the decoded MP3 data and interfaces to the decoder through a 16bit data input and data request signal. This signal asks for data when the buffer has enough space to receive new data. Data request is conditioned by the DREQEN bit in AUDCON1 register. When set, the buffer requests data to the MP3 decoder. When cleared no more data is requested but data are output until the buffer is empty. This bit can be used to suspend the audio generation (pause mode). 14.6 Interrupt Request The audio interrupt request can be generated by 2 sources when in C51 audio mode: a sample request when SREQ flag in AUDSTA register is set to logic 1, and an under-run condition when UDRN flag in AUDSTA register is set to logic 1. Both sources can be enabled separately by masking one of them using the MSREQ and MUDRN bits in AUDCON1 register. A global enable of the audio interface is provided by setting the EAUD bit in IEN0 register. The interrupt is requested each time one of the 2 sources is set to one. The source flags are cleared by writing some data in the audio buffer through AUDDAT, but the global audio interrupt flag is cleared by hardware when the interrupt service routine is executed. Figure 14-5. Audio Interface Interrupt System UDRN AUDSTA.6 MUDRN AUDCON1.4 Audio Interrupt Request EAUD IEN0.6 SREQ AUDSTA.7 MSREQ AUDCON1.5 14.7 MP3 Song Playing In MP3 song playing mode, the operations to do are to configure the PLL and the audio interface according to the DAC selected. The audio clock is programmed to generate the 256·Fs or 384·Fs as explained in Section "Clock Generator", page 75. Figure 14-6 shows the configuration flow of the audio interface when in MP3 song mode. 77 4341F–MP3–03/06 Figure 14-6. MP3 Mode Audio Configuration Flow MP3 Mode Configuration Enable DAC System Clock AUDEN = 1 Program Audio Clock Configure Interface HLR = X DSIZ = X POL = X JUST4:0 = XXXXXb SRC = 0 Wait For DAC Set-up Time Enable Data Request DRQEN = 1 14.8 Registers Table 14-3. AUDCON0 Register AUDCON0 (S:9Ah) – Audio Interface Control Register 0 7 JUST4 6 JUST3 Bit Mnemonic JUST4:0 5 JUST2 4 JUST1 3 JUST0 2 POL 1 DSIZ 0 HLR Bit Number 7-3 Description Audio Stream Justification Bits R efer to Section "Data Converter", page 75 for bits description. DSEL Signal Output Polarity Set to output the left channel on high level of DSEL output (PCM mode). C lear to output the left channel on the low level of DSEL output (I2S mode). Audio Data Size Set to select 32-bit data output format. C lear to select 16-bit data output format. High/Low Rate Bit Set by software when the PLL clock frequency is 384·Fs. C lear by software when the PLL clock frequency is 256·Fs. 2 POL 1 DSIZ 0 HLR Reset Value = 0000 1000b Table 14-4. AUDCON1 Register AUDCON1 (S:9Bh) – Audio Interface Control Register 1 7 SRC 6 DRQEN Bit Mnemonic 5 MSREQ 4 MUDRN 3 2 DUP1 1 DUP0 0 AUDEN Bit Number Description Audio Source Bit Set to select C51 as audio source for voice or sound playing. C lear to select the MP3 decoder output as audio source for song playing. 7 SRC 78 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B Bit Number Bit Mnemonic Description MP3 Decoded Data Request Enable Bit Set to enable data request to the MP3 decoder and to start playing song. C lear to disable data request to the MP3 decoder. Audio Sample Request Flag Mask Bit Set to prevent the SREQ flag from generating an audio interrupt. C lear to allow the SREQ flag to generate an audio interrupt. Audio Sample Under-run Flag Mask Bit Set to prevent the UDRN flag from generating an audio interrupt. C lear to allow the UDRN flag to generate an audio interrupt. Reserved The value read from this bit is always 0. Do not set this bit. Audio Duplication Factor R efer to Table 14-2 for bits description. Audio Interface Enable Bit Set to enable the audio interface. C lear to disable the audio interface. 6 DRQEN 5 MSREQ 4 MUDRN 3 - 2-1 DUP1:0 0 AUDEN Reset Value = 1011 0010b Table 14-5. 7 SREQ AUDSTA Register AUDSTA (S:9Ch Read Only) – Audio Interface Status Register 6 UDRN Bit Mnemonic 5 AUBUSY 4 3 2 1 0 - Bit Number Description Audio Sample Request Flag Set in C51 audio source mode when the audio interface request samples (buffer half empty). This bit generates an interrupt if not masked and if enabled in IEN0. C leared by hardware when samples are loaded in AUDDAT. Audio Sample Under-run Flag Set in C51 audio source mode when the audio interface runs out of samples (buffer empty). This bit generates an interrupt if not masked and if enabled in IEN0. C leared by hardware when samples are loaded in AUDDAT. Audio Interface Busy Bit Set in C51 audio source mode when the audio interface can not accept more sample (buffer full). C leared by hardware when buffer is no more full. Reserved The value read from these bits is always 0. Do not set these bits. 7 SREQ 6 UDRN 5 AUBUSY 4-0 - Reset Value = 1100 0000b 79 4341F–MP3–03/06 Table 14-6. 7 AUD7 AUDDAT Register AUDDAT (S:9Dh) – Audio Interface Data Register 6 AUD6 Bit Mnemonic AUD7:0 5 AUD5 4 AUD4 3 AUD3 2 AUD2 1 AUD1 0 AUD0 Bit Number 7-0 Description Audio Data 8-bit sampling data for voice or sound playing. Reset Value = 1111 1111b Table 14-7. 7 - AUDCLK Register AUDCLK (S:ECh) – Audio Clock Divider Register 6 Bit Mnemonic 5 4 AUCD4 3 AUCD3 2 AUCD2 1 AUCD1 0 AUCD0 Bit Number 7-5 Description Reserved The value read from these bits is always 0. Do not set these bits. Audio Clock Divider 5-bit divider for audio clock generation. 4-0 AUCD4:0 Reset Value = 0000 0000b 80 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B 15. DAC and PA Interface The AT8xC51SND2C implements a stereo Audio Digital-to-Analog Converter and Audio Power Amplifier targeted for Li-Ion or Ni-Mh battery powered devices. Figure 15-1. Audio Interface Block Diagram MP3 Decoder Unit DOUT DCLK DSEL SCLK I2S/PCM Audio Interface Serial Audio Interface HSR HSL AUXP AUXN LINEL LINER MONOP MONON Audio DAC AUDCDIN AUDCDOUT AUDCCLK AUDCCS PAINP PAINN HPP HPN Audio PA 15.1 DAC The Stereo DAC section is a complete high performance, stereo, audio digital-to-analog converter delivering 93 dB Dynamic Range. It comprises a multibit sigma-delta modulator with dither, continuous time analog filters and analog output drive circuitry. This architecture provides a high insensitivity to clock jitter. The digital interpolation filter increases the sample rate by a factor of 8 using 3 linear phase half-band filters cascaded, followed by a first order SINC interpolator with a factor of 8. This filter eliminates the images of baseband audio, remaining only the image at 64x the input sample rate, which is eliminated by the analog post filter. Optionally, a dither signal can be added that may reduce eventual noise tones at the output. However, the use of a multibit sigma-delta modulator already provides extremely low noise tones energy. Master clock is 128 up to 512 times the input data rate allowing choice of input data rate up to 50 kHz, including standard audio rates of 48, 44.1, 32, 16 and 8 kHz. The DAC section is followed by a volume and mute control and can be simultaneously played back directly through a Stereo 32Ω H eadset pair of drivers. The Stereo 32Ω H eadset pair of drivers also includes a mixer of a LINEL and LINER pair of stereo inputs as well as a differential monaural auxiliary input (line level). 81 4341F–MP3–03/06 15.1.1 DAC Features • • • • • • • • 20 bit D/A Conversion 72dB Dynamic Range, -75dB THD Stereo line-in or microphone interface with 20dB amplification 93dB Dynamic Range, -80dB THD Stereo D/A conversion 74dB Dynamic Range / -65dB THD for 20mW output power over 32 Ohm loads Stereo, Mono and Reverse Stereo Mixer Left/Right speaker short-circuit detection flag Differential mono auxiliary input amplifier and PA driver Audio sampling rates (Fs): 16, 22.05, 24, 32, 44.1 and 48 kHz. Figure 15-2. Stereo DAC functional diagram niaG AP 82 AT8xC51SND2C/MP3B 4341F–MP3–03/06 TUOD KLCD KLCS LESD ecafretnI lellaraP ot laireS retliF latigiD retliF latigiD )Bd5.1( Bd43- ot 21 niaG kcabyalP retsaM lortnoC emuloV lortnoC emuloV + + )Bd5.1( Bd5.64- ot 0 GOLR ,GOLL niaG tuO eniL lortnoC emuloV lortnoC emuloV CAD CAD + + + )Bd3( Bd 33- ot 21,02 niaG GILR,GILL niaG GXUA )Bd3( Bd6- ot 6 niaG CLO_CAD 23 VRD RKPS 23 VRD RKPS VRDAP AGP AGP XUA RSH NXUA RENIL NONOM PXUA PONOM LSH LENIL AT8xC51SND2C/MP3B 15.1.2 15.1.2.1 Digital Signals Timing Data Interface To avoid noises at the output, the reset state is maintained until proper synchronism is achieved in the DAC serial interface: • • • • DSEL SCLK DCLK DOUT The data interface allows three different data transfer modes: Figure 15-3. 20 bit I2S justified mode SCLK DSEL DOUT R1 R0 L(N-1) L(N-2) L(N-3) ... L2 L1 L0 R(N-1) R(N-2) R(N-3) ... R2 R1 R0 Figure 15-4. 20 bit MSB justified mode SCLK DSEL DOUT R0 L(N-1) L(N-2) L(N-3) ... L2 L1 L0 R(N-1) R(N-2) R(N-3) ... R2 R1 R0 L(N-1) Figure 15-5. 20 bit LSB justified mode SCLK DSEL DOUT R0 L(N-1) L(N-2) ... L1 L0 R(N-1) R(N-2) ... R1 R0 L(N-1) The selection between modes is done using the DINTSEL 1:0 in DAC_MISC register (Table 1522.) according with the following table: DINTSEL 1:0 00 01 1x Format I2S Justified MSB Justified LSB Justified The data interface always works in slave mode. This means that the DSEL and the DCLK signals are provided by microcontroller audio data interface. 83 4341F–MP3–03/06 15.1.3 Serial Audio DAC Interface The serial audio DAC interface is a Synchronous Peripheral Interface (SPI) in slave mode: • • • AUDCDIN: is used to transfer data in series from the master to the slave DAC. It is driven by the master. AUDCDOUT: is used to transfer data in series from the slave DAC to the master. It is driven by the selected slave DAC. Serial Clock (AUDCCLK): it is used to synchronize the data transmission both in and out the devices through the AUDCDIN and AUDCDOUT lines. Refer to Table 15-11. for DAC SPI Interface Description Note: Figure 15-6. Serial Audio Interface Serial Audio Interface Audio DAC AUDCDIN AUDCDOUT AUDCCLK AUDCCS Audio PA Protocol is as following to access DAC registers: 84 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B Figure 15-7. Dac SPI Interface AUDCCS AUDCCLK AUDCDIN AUDCDOUT 15.1.4 DAC Interface SPI Protocol On AUDCDIN, the first bit is a read/write bit. 0 indicates a write operation while 1 is for a read operation. The 7 following bits are used for the register address and the 8 last ones are the write data. For both address and data, the most significant bit is the first one. In case of a read operation, AUDCDOUT provides the contents of the read register, MSB first. The transfer is enabled by the AUDCCS signal active low. The interface is resetted at every rising edge of AUDCCS in order to come back to an idle state, even if the transfer does not succeed. The DAC Interface SPI is synchronized with the serial clock AUDCCLK. Falling edge latches AUDCDIN input and rising edge shifts AUDCDOUT output bits. Note that the DLCK must run during any DAC SPI interface access (read or write). Figure 15-8. DAC SPI Interface Timings AUDCCS AUDCCLK AUDCDIN AUDCDOUT 4341F–MP3–03/06 neshT 0d 1d 2d 3d 4d 5d 0d 1d 2d 3d 4d 5d 6d 7d hwT 6d odshT 7d 0 a 1 a 2a 3a 4a 5a 6a wr cT lwT idshT idssT odsdT nessT 85 Table 15-1. Dac SPI Interface Timings Description AUDCCLK min period AUDCCLK min pulse width low AUDCCLK min pulse width high Setup time AUDCCS falling to AUDCCLK rising Hold time AUDCCLK falling to AUDCCS rising Setup time AUDCDIN valid to AUDCCLK falling Hold time AUDCCLK falling to AUDCDIN not valid Delay time AUDCCLK rising to AUDCDOUT valid Hold time AUDCCLK rising to AUDCDOUT not valid Min 150 ns 50 ns 50 ns 50 ns 50 ns 20 ns 20 ns 0 ns Max 20 ns - Timing parameter Tc Twl Twh Tssen Thsen Tssdi Thsdi Tdsdo Thsdo 15.1.5 DAC Register Tables Table 15-2. Address 00h 01h 02h 03h 04h 05h 06h 07h 08h 09h 0Ah 0Ch 0Dh 10h 11h DAC Register Address Name Dac Control Dac Left Line in Gain Dac Right Line in Gain Dac Left Master Playback Gain Dac Right Master Playback Gain Dac Left Line Out Gain Dac Right Line Out Gain Dac Output Level Control Dac Mixer Control Dac Clock and Sampling Frequency Control Dac Miscellaneous Dac Precharge Control Dac Auxilary input gain Control Dac Reset Power Amplifier Control Access Read/Write Read/Write Read/Write Read/Write Read/Write Read/Write Read/Write Read/Write Read/Write Read/Write Read/Write Read/Write Read/Write Read/Write Read/Write Reset state 00h 05h 05h 08h 08h 00h 00h 22h 09h 00h 00h 00h 05h 00h 00h Register DAC_CTRL DAC_LLIG DAC_RLIG DAC_LPMG DAC_RPMG DAC_LLOG DAC_RLOG DAC_OLC DAC_MC DAC_CSFC DAC_MISC DAC_PRECH DAC_AUXG DAC_RST PA_CRTL 15.1.6 DAC Gain The DAC implements severals gain control: line-in (Table 15-3. ), master playback (), line-out (Table 15-6.). 86 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B Table 15-3. Line-in gain LLIG 4:0 RLIG 4:0 00000 00001 00010 00011 00100 00101 00110 00111 01000 01001 01010 01011 01100 01101 01110 01111 10000 10001 Gain (dB) 20 12 9 6 3 0 -3 -6 -9 -12 -15 -18 -21 -24 -27 -30 -33 < -60 Table 15-4. Master Playback Gain LMPG 5:0 RMPG 5:0 000000 000001 000010 000011 000100 000101 000110 000111 001000 001001 001010 Gain (dB) 12.0 10.5 9.0 7.5 6.0 4.5 3.0 1.5 0.0 -1.5 -3.0 87 4341F–MP3–03/06 Table 15-4. Master Playback Gain (Continued) LMPG 5:0 RMPG 5:0 001011 001100 001101 001110 001111 010000 010001 010010 010011 010100 010101 010110 010111 011000 011001 011010 011011 011100 011101 011110 011111 100000 Gain (dB) -4.5 -6.0 -7.5 -9.0 -10.5 -12.0 -13.5 -15.0 -16.5 -18.0 -19.5 -21.0 -22.5 -24.0 -25.5 -27.0 -28.5 -30.0 -31.5 -33.0 -34.5 mute Table 15-5. Line-out Gain LLOG 5:0 RLOG 5:0 000000 000001 000010 000011 000100 000101 000110 000111 Gain (dB) 0.0 -1.5 -3.0 -4.5 -6.0 -7.5 -9.0 -10.5 88 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B Table 15-5. Line-out Gain (Continued) 001000 001001 001010 001011 001100 001101 001110 001111 010000 010001 010010 010011 010100 010101 010110 010111 011000 011001 011010 011011 011100 011101 011110 011111 100000 -12.0 -13.5 -15.0 -16.5 -18.0 -19.5 -21.0 -22.5 -24.0 -25.5 -27.0 -28.5 -30.0 -31.5 -33.0 -34.5 -36.0 -37.5 -39.0 -40.5 -42.0 -43.5 -45.0 -46.5 mute Table 15-6. DAC Output Level Control LOLC 2:0 ROLC 2:0 000 001 010 011 100 Gain (dB) 6 3 0 -3 -6 89 4341F–MP3–03/06 15.1.7 Digital Mixer Control The Audio DAC features a digital mixer that allows the mixing and selection of multiple input sources. The mixing / multiplexing functions are described in the following table according with the next figure: Figure 15-9. Mixing / Multiplexing functions Left channel Volume Control + 2 1 Volume Control To DACs 1 From digital filters Volume Control + 2 Volume Control Right channel Note: Whenever the two mixer inputs are selected, a –6 dB gain is applied to the output signal. Whenever only one input is selected, no gain is applied. Signal LMSMIN1 LMSMIN2 RMSMIN1 RMSMIN2 Description Left Channel Mono/Stereo Mixer Left Mixed input enable – High to enable, Low to disable Left Channel Mono/Stereo Mixer Right Mixed input enable – High to enable, Low to disable Right Channel Mono/Stereo Mixer Left Mixed input enable – High to enable, Low to disable Right Channel Mono/Stereo Mixer Right Mixed input enable – High to enable, Low to disable Note: Refer to DAC_MC register Table 15-20. for signal description 15.1.8 Master Clock and Sampling Frequency Selection The following table describes the different modes available for master clock and sampling frequency selection by setting OVRSEL bit in DAC_CSFC register (refer to Table 15-21.). Table 15-7. Master Clock selection OVRSEL 0 1 Master Clock 256 x FS 384 x FS The selection of input sample size is done using the NBITS 1:0 in DAC_MISC register (refer to Table 15-22.) according to Table 15-8. Table 15-8. Input Sample Size Selection NBITS 1:0 00 01 10 Format 16 bits 18 bits 20 bits 90 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B The selection between modes is done using DINTSEL 1:0 in DAC_MISC register (refer to Table 15-22.) according to Table 15-9. Table 15-9. Format Selection DINTSEL 1:0 00 01 1x Format I2S Justified MSB Justified LSB Justified 15.1.9 De-emphasis and dither enable The circuit features a de-emphasis filter for the playback channel. To enable the de-emphasis filtering, DEEMPEN must be set to high. Likewise, the dither option (added in the playback channel) is enabled by setting the DITHEN signal to High. Table 15-10. DAC Auxlilary Input Gain AUXG 4:0 00000 00001 00010 00011 00100 00101 00110 00111 01000 01001 01010 01011 01100 01101 01110 01111 10000 10001 Gain (dB) 20 12 9 6 3 0 -3 -6 -9 -12 -15 -18 -21 -24 -27 -30 -33 Serial CRC7 Generator CTPTR MMCON0.4 TX COMMAND Line Finished State Machine CFLCK MMSTA.0 MMINT.5 EOCI MCMD CMDEN Command Transmitter MMCON1.0 MMSTA.2 MMSTA.1 CRC7S Data Converter Serial -> // RESPFS RX Pointer 17 - Byte FIFO MMCMD Read CRC7 and Format Checker CRPTR MMCON0.5 RX COMMAND Line Finished State Machine RESPEN Command Receiver MMINT.6 EORI RFMT CRCDIS MMCON1.1 MMCON0.1 MMCON0.0 18.5.1 Command Transmitter For sending a command to the card, user must load the command index (1 Byte) and argument (4 Bytes) in the command transmit FIFO using the MMCMD register. Before starting transmission by setting and clearing the CMDEN bit in MMCON1 register, user must first configure: • • • RESPEN bit in MMCON1 register to indicate whether a response is expected or not. RFMT bit in MMCON0 register to indicate the response size expected. CRCDIS bit in MMCON0 register to indicate whether the CRC7 included in the response will be computed or not. In order to avoid CRC error, CRCDIS may be set for response that do not include CRC7. Figure 18-13 summarizes the command transmission flow. As soon as command transmission is enabled, the CFLCK flag in MMSTA is set indicating that write to the FIFO is locked. This mechanism is implemented to avoid command overrun. The end of the command transmission is signalled to you by the EOCI flag in MMINT register becoming set. This flag may generate an MMC interrupt request as detailed in Section "Interrupt", page 148. The end of the command transmission also resets the CFLCK flag. User may abort command loading by setting and clearing the CTPTR bit in MMCON0 register which resets the write pointer to the transmit FIFO. 141 4341F–MP3–03/06 Figure 18-13. Command Transmission Flow Command Transmission Load Command in Buffer MMCMD = index MMCMD = argument Configure Response RESPEN = X RFMT = X CRCDIS = X Transmit Command CMDEN = 1 CMDEN = 0 18.5.2 Command Receiver The end of the response reception is signalled to you by the EORI flag in MMINT register. This flag may generate an MMC interrupt request as detailed in Section "Interrupt", page 148. When t his flag is set, 2 other flags in MMSTA register: RESPFS and CRC7S give a status on the response received. RESPFS indicates if the response format is correct or not: the size is the one expected (48 bits or 136 bits) and a valid End bit has been received, and CRC7S indicates if the CRC7 computation is correct or not. These Flags are cleared when a command is sent to the card and updated when the response has been received. User may abort response reading by setting and clearing the CRPTR bit in MMCON0 register which resets the read pointer to the receive FIFO. According to the MMC specification delay between a command and a response (formally NCR parameter) can not exceed 64 MMC clock periods. To avoid any locking of the MMC controller when card does not send its response (e.g. physically removed from the bus), user must launch a time-out period to exit from such situation. In case of time-out user may reset the command controller and its internal state machine by setting and clearing the CCR bit in MMCON2 register. This time-out may be disarmed when receiving the response. 18.6 Data Line Controller The data line controller is based on a 16-Byte FIFO used both by the data transmitter channel and by the data receiver channel. 142 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B Figure 18-14. Data Line Controller Block Diagram MMINT.0 MMINT.2 MMSTA.3 MMSTA.4 F1EI F1FI DATFS CRC16S Data Converter Serial -> // CRC16 and Format Checker 8-Byte TX Pointer FIFO 1 MCBI MMINT.1 CBUSY MMSTA.5 MDAT CRC16 Generator DTPTR MMCON0.6 RX Pointer 16-Byte FIFO MMDAT 8-Byte FIFO 2 Data Converter // -> Serial DRPTR MMCON0.7 DATA Line Finished State Machine DFMT MBLOCK MMCON0.3 MMINT.4 EOFI DATEN MMCON1.2 DATDIR BLEN3:0 F2EI MMINT.1 F2FI MMINT.3 MMCON0.2 MMCON1.3 MMCON1.7:4 18.6.1 FIFO Implementation The 16-Byte FIFO is based on a dual 8-Byte FIFOs managed using 2 pointers and four flags indicating the status full and empty of each FIFO. Pointers are not accessible to user but can be reset at any time by setting and clearing DRPTR and DTPTR bits in MMCON0 register. Resetting the pointers is equivalent to abort the writing or reading of data. F1EI and F2EI flags in MMINT register signal when set that respectively FIFO1 and FIFO2 are empty. F1FI and F2FI flags in MMINT register signal when set that respectively FIFO1 and FIFO2 are full. These flags may generate an MMC interrupt request as detailed in Section “Interrupt”. 18.6.2 Data Configuration Before sending or receiving any data, the data line controller must be configured according to the type of the data transfer considered. This is achieved using the Data Format bit: DFMT in MMCON0 register. Clearing DFMT bit enables the data stream format while setting DFMT bit enables the data block format. In data block format, user must also configure the single or multiblock mode by clearing or setting the MBLOCK bit in MMCON0 register and the block length using BLEN3:0 bits in MMCON1 according to Table 18-7. Figure 18-15 summarizes the data modes configuration flows. Table 18-7. Block Length Programming BLEN3:0 Block Length (Byte) Length = 2BLEN: 1 to 2048 Reserved: do not program BLEN3:0 > 1011 BLEN = 0000 to 1011 > 1011 143 4341F–MP3–03/06 Figure 18-15. Data Controller Configuration Flows Data Stream Configuration Data Single Block Configuration Data Multi-Block Configuration Configure Format DFMT = 0 Configure Format DFMT = 1 MBLOCK = 0 BLEN3:0 = XXXXb Configure Format DFMT = 1 MBLOCK = 1 BLEN3:0 = XXXXb 18.6.3 18.6.3.1 Data Transmitter Configuration For transmitting data to the card user must first configure the data controller in transmission mode by setting the DATDIR bit in MMCON1 register. Figure 18-16 summarizes the data stream transmission flows in both polling and interrupt modes while Figure 18-17 summarizes the data block transmission flows in both polling and interrupt modes, these flows assume that block length is greater than 16 data. 18.6.3.2 Data Loading Data is loaded in the FIFO by writing to MMDAT register. Number of data loaded may vary from 1 to 16 Bytes. Then if necessary (more than 16 Bytes to send) user must wait that one FIFO becomes empty (F1EI or F2EI set) before loading 8 new data. 18.6.3.3 Data Transmission Transmission is enabled by setting and clearing DATEN bit in MMCON1 register. Data is transmitted immediately if the response has already been received, or is delayed after the response reception if its status is correct. In both cases transmission is delayed if a card sends a busy state on the data line until the end of this busy condition. According to the MMC specification, the data transfer from the host to the card may not start sooner than 2 MMC clock periods after the card response was received (formally NWR parameter). To address all card types, this delay can be programmed using DATD1:0 bits in MMCON2 register from 3 MMC clock periods when DATD1:0 bits are cleared to 9 MMC clock periods when DATD1:0 bits are set, by step of 2 MMC clock periods. 18.6.3.4 End of Transmission The end of a data frame (block or stream) transmission is signalled to you by the EOFI flag in MMINT register. This flag may generate an MMC interrupt request as detailed in Section "Interrupt", page 148. In data stream mode, EOFI flag is set, after reception of the End bit. This assumes user has previously sent the STOP command to the card, which is the only way to stop stream transfer. In data block mode, EOFI flag is set, after reception of the CRC status token (see Figure 18-7). 2 other flags in MMSTA register: DATFS and CRC16S report a status on the frame sent. DATFS indicates if the CRC status token format is correct or not, and CRC16S indicates if the card has found the CRC16 of the block correct or not. 18.6.3.5 Busy Status As shown in Figure 18-7 the card uses a busy token during a block write operation. This busy status is reported to you by the CBUSY flag in MMSTA register and by the MCBI flag in MMINT 144 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B which is set every time CBUSY toggles, i.e. when the card enters and exits its busy state. This flag may generate an MMC interrupt request as detailed in Section "Interrupt", page 148. Figure 18-16. Data Stream Transmission Flows Data Stream Transmission Data Stream Initialization Data Stream Transmission ISR FIFOs Filling write 16 data to MMDAT FIFOs Filling write 16 data to MMDAT FIFO Empty? F1EI or F2EI = 1? Start Transmission DATEN = 1 DATEN = 0 Unmask FIFOs Empty F1EM = 0 F2EM = 0 FIFO Filling write 8 data to MMDAT FIFO Empty? F1EI or F2EI = 1? Start Transmission DATEN = 1 DATEN = 0 No More Data To Send? FIFO Filling write 8 data to MMDAT Mask FIFOs Empty F1EM = 1 F2EM = 1 No More Data To Send? Send STOP Command Send STOP Command b. Interrupt mode a. Polling mode 145 4341F–MP3–03/06 Figure 18-17. Data Block Transmission Flows D ata Block Transmission Data Block Initialization Data Block Transmission ISR FIFOs Filling write 16 data to MMDAT FIFOs Filling write 16 data to MMDAT FIFO Empty? F1EI or F2EI = 1? Start Transmission DATEN = 1 DATEN = 0 Unmask FIFOs Empty F1EM = 0 F2EM = 0 FIFO Filling write 8 data to MMDAT FIFO Empty? F1EI or F2EI = 1? Start Transmission DATEN = 1 DATEN = 0 No More Data To Send? FIFO Filling write 8 data to MMDAT Mask FIFOs Empty F1EM = 1 F2EM = 1 No More Data To Send? b. Interrupt mode a. Polling mode 18.6.4 18.6.4.1 Data Receiver Configuration To receive data from the card you must first configure the data controller in reception mode by clearing the DATDIR bit in MMCON1 register. Figure 18-18 summarizes the data stream reception flows in both polling and interrupt modes while F igure 1 8-19 summarizes the data block reception flows in both polling and interrupt modes, these flows assume that block length is greater than 16 Bytes. 18.6.4.2 Data Reception The end of a data frame (block or stream) reception is signalled to you by the EOFI flag in MMINT register. This flag may generate an MMC interrupt request as detailed in Section "Interrupt", page 148. When this flag is set, 2 other flags in MMSTA register: DATFS and CRC16S give a status on the frame received. DATFS indicates if the frame format is correct or not: a valid End bit has been received, and CRC16S indicates if the CRC16 computation is correct or not. In case of data stream CRC16S has no meaning and stays cleared. According to the MMC specification data transmission from the card starts after the access time delay (formally NAC parameter) beginning from the End bit of the read command. To avoid any locking of the MMC controller when card does not send its data (e.g. physically removed from the bus), you must launch a time-out period to exit from such situation. In case of time-out you 146 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B may reset the data controller and its internal state machine by setting and clearing the DCR bit in MMCON2 register. This time-out may be disarmed after receiving 8 data (F1FI flag set) or after receiving end of frame (EOFI flag set) in case of block length less than 8 data (1, 2 or 4). 18.6.4.3 Data Reading Data is read from the FIFO by reading to MMDAT register. Each time one FIFO becomes full (F1FI or F2FI set), user is requested to flush this FIFO by reading 8 data. Figure 18-18. Data Stream Reception Flows Data Stream Reception Data Stream Initialization Data Stream Reception ISR FIFO Full? F1FI or F2FI = 1? Unmask FIFOs Full F1FM = 0 F2FM = 0 FIFO Full? F1FI or F2FI = 1? FIFO Reading read 8 data from MMDAT FIFO Reading read 8 data from MMDAT No More Data To Receive? No More Data To Receive? Send STOP Command Mask FIFOs Full F1FM = 1 F2FM = 1 a. Polling mode Send STOP Command b. Interrupt mode 147 4341F–MP3–03/06 Figure 18-19. Data Block Reception Flows Data Block Reception Data Block Initialization Data Block Reception ISR Start Transmission DATEN = 1 DATEN = 0 Unmask FIFOs Full F1FM = 0 F2FM = 0 FIFO Full? F1EI or F2EI = 1? FIFO Full? F1EI or F2EI = 1? Start Transmission DATEN = 1 DATEN = 0 FIFO Reading read 8 data from MMDAT FIFO Reading read 8 data from MMDAT No More Data To Receive? No More Data To Receive? Mask FIFOs Full F1FM = 1 F2FM = 1 a. Polling mode b. Interrupt mode 18.6.5 Flow Control To allow transfer at high speed without taking care of CPU oscillator frequency, the FLOWC bit in MMCON2 allows control of the data flow in both transmission and reception. During transmission, setting the FLOWC bit has the following effects: • • • • MMCLK is stopped when both FIFOs become empty: F1EI and F2EI set. MMCLK is restarted when one of the FIFOs becomes full: F1EI or F2EI cleared. MMCLK is stopped when both FIFOs become full: F1FI and F2FI set. MMCLK is restarted when one of the FIFOs becomes empty: F1FI or F2FI cleared. During reception, setting the FLOWC bit has the following effects: As soon as the clock is stopped, the MMC bus is frozen and remains in its state until the clock is restored by writing or reading data in MMDAT. 18.7 18.7.1 Interrupt Description As shown in Figure 18-20, the MMC controller implements eight interrupt sources reported in MCBI, EORI, EOCI, EOFI, F2FI, F1FI, and F2EI flags in MMCINT register. These flags are detailed in the previous sections. All these sources are maskable separately using MCBM, EORM, EOCM, EOFM, F2FM, F1FM, and F2EM mask bits respectively in MMMSK register. 148 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B The interrupt request is generated each time an unmasked flag is set, and the global MMC controller interrupt enable bit is set (EMMC in IEN1 register). Reading the MMINT register automatically clears the interrupt flags (acknowledgment). This implies that register content must be saved and tested interrupt flag by interrupt flag to be sure not to forget any interrupts. Figure 18-20. MMC Controller Interrupt System MCBI MMINT.7 MCBM EORI MMINT.6 MMMSK.7 EORM EOCI MMINT.5 MMMSK.6 EOCM EOFI MMINT.4 MMMSK.5 EOFM F2FI MMINT.3 MMMSK.4 MMC Interface Interrupt Request EMMC F2FM IEN1.0 MMMSK.3 F1FI MMINT.2 F1FM F2EI MMINT.1 MMMSK.2 F2EM F1EI MMINT.0 MMMSK.1 F1EM MMMSK.0 149 4341F–MP3–03/06 18.8 Registers Table 18-8. MMCON0 Register MMCON0 (S:E4h) – MMC Control Register 0 7 DRPTR 6 DTPTR Bit Mnemonic 5 CRPTR 4 CTPTR 3 MBLOCK 2 DFMT 1 RFMT 0 CRCDIS Bit Number Description Data Receive Pointer Reset Bit Set to reset the read pointer of the data FIFO. C lear to release the read pointer of the data FIFO. Data Transmit Pointer Reset Bit Set to reset the write pointer of the data FIFO. C lear to release the write pointer of the data FIFO. Command Receive Pointer Reset Bit Set to reset the read pointer of the receive command FIFO. C lear to release the read pointer of the receive command FIFO. Command Transmit Pointer Reset Bit Set to reset the write pointer of the transmit command FIFO. C lear to release the read pointer of the transmit command FIFO. Multi-block Enable Bit Set to select multi-block data format. C lear to select single block data format. Data Format Bit Set to select the block-oriented data format. C lear to select the stream data format. Response Format Bit Set to select the 48-bit response format. C lear to select the 136-bit response format. CRC7 Disable Bit Set to disable the CRC7 computation when receiving a response. C lear to enable the CRC7 computation when receiving a response. 7 DRPTR 6 DTPTR 5 CRPTR 4 CTPTR 3 MBLOCK 2 DFMT 1 RFMT 0 CRCDIS Reset Value = 0000 0000b 150 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B Table 18-9. MMCON1 Register MMCON1 (S:E5h) – MMC Control Register 1 7 BLEN3 6 BLEN2 Bit Mnemonic BLEN3:0 5 BLEN1 4 BLEN0 3 DATDIR 2 DATEN 1 RESPEN 0 CMDEN Bit Number 7-4 Description Block Length Bits R efer to Table 18-7 for bits description. Do not program value > 1011b Data Direction Bit Set to select data transfer from host to card (write mode). C lear to select data transfer from card to host (read mode). Data Transmission Enable Bit Set and clear to enable data transmission immediately or after response has been received. Response Enable Bit Set and clear to enable the reception of a response following a command transmission. Command Transmission Enable Bit Set and clear to enable transmission of the command FIFO to the card. 3 DATDIR 2 DATEN 1 RESPEN 0 CMDEN Reset Value = 0000 0000b Table 18-10. MMCON2 Register MMCON2 (S:E6h) – MMC Control Register 2 7 MMCEN 6 DCR Bit Mnemonic 5 CCR 4 3 2 DATD1 1 DATD0 0 FLOWC Bit Number Description MMC Clock Enable Bit S et to enable the MCLK clocks and activate the MMC controller. C lear to disable the MMC clocks and freeze the MMC controller. Data Controller Reset Bit Set and clear to reset the data line controller in case of transfer abort. Command Controller Reset Bit Set and clear to reset the command line controller in case of transfer abort. Reserved The value read from these bits is always 0. Do not set these bits. Data Transmission Delay Bits U sed to delay the data transmission after a response from 3 MMC clock periods (all bits cleared) to 9 MMC clock periods (all bits set) by step of 2 MMC clock periods. MMC Flow Control Bit Set to enable the flow control during data transfers. C lear to disable the flow control during data transfers. 7 MMCEN 6 DCR 5 CCR 4-3 - 2-1 DATD1:0 0 FLOWC Reset Value = 0000 0000b 151 4341F–MP3–03/06 Table 18-11. MMSTA Register MMSTA (S:DEh Read Only) – MMC Control and Status Register 7 6 Bit Mnemonic 5 CBUSY 4 CRC16S 3 DATFS 2 CRC7S 1 RESPFS 0 CFLCK Bit Number 7-6 Description Reserved The value read from these bits is always 0. Do not set these bits. Card Busy Flag S et by hardware when the card sends a busy state on the data line. C leared by hardware when the card no more sends a busy state on the data line. CRC16 Status Bit Transmission mode Set by hardware when the token response reports a good CRC. C leared by hardware when the token response reports a bad CRC. R eception mode Set by hardware when the CRC16 received in the data block is correct. C leared by hardware when the CRC16 received in the data block is not correct. Data Format Status Bit Transmission mode Set by hardware when the format of the token response is correct. C leared by hardware when the format of the token response is not correct. R eception mode Set by hardware when the format of the frame is correct. C leared by hardware when the format of the frame is not correct. CRC7 Status Bit Set by hardware when the CRC7 computed in the response is correct. C leared by hardware when the CRC7 computed in the response is not correct. This bit is not relevant when CRCDIS is set. Response Format Status Bit S et by hardware when the format of a response is correct. C leared by hardware when the format of a response is not correct. Command FIFO Lock Bit Set by hardware to signal user not to write in the transmit command FIFO: busy state. C leared by hardware to signal user the transmit command FIFO is available: idle state. 5 CBUSY 4 CRC16S 3 DATFS 2 CRC7S 1 RESPFS 0 CFLCK Reset Value = 0000 0000b 152 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B Table 18-12. MMINT Register MMINT (S:E7h Read Only) – MMC Interrupt Register 7 MCBI 6 EORI Bit Mnemonic 5 EOCI 4 EOFI 3 F2FI 2 F1FI 1 F2EI 0 F1EI Bit Number Description MMC Card Busy Interrupt Flag Set by hardware when the card enters or exits its busy state (when the busy signal is asserted or deasserted on the data line). C leared when reading MMINT. End of Response Interrupt Flag Set by hardware at the end of response reception. C leared when reading MMINT. End of Command Interrupt Flag Set by hardware at the end of command transmission. C lear when reading MMINT. End of Frame Interrupt Flag Set by hardware at the end of frame (stream or block) transfer. C lear when reading MMINT. FIFO 2 Full Interrupt Flag Set by hardware when second FIFO becomes full. C leared by hardware when second FIFO becomes empty. FIFO 1 Full Interrupt Flag Set by hardware when first FIFO becomes full. C leared by hardware when first FIFO becomes empty. FIFO 2 Empty Interrupt Flag Set by hardware when second FIFO becomes empty. C leared by hardware when second FIFO becomes full. FIFO 1 Empty Interrupt Flag Set by hardware when first FIFO becomes empty. C leared by hardware when first FIFO becomes full. 7 MCBI 6 EORI 5 EOCI 4 EOFI 3 F2FI 2 F1FI 1 F2EI 0 F1EI Reset Value = 0000 0011b 153 4341F–MP3–03/06 Table 18-13. MMMSK Register MMMSK (S:DFh) – MMC Interrupt Mask Register 7 MCBM 6 EORM Bit Mnemonic 5 EOCM 4 EOFM 3 F2FM 2 F1FM 1 F2EM 0 F1EM Bit Number Description MMC Card Busy Interrupt Mask Bit Set to prevent MCBI flag from generating an MMC interrupt. C lear to allow MCBI flag to generate an MMC interrupt. End Of Response Interrupt Mask Bit Set to prevent EORI flag from generating an MMC interrupt. C lear to allow EORI flag to generate an MMC interrupt. End Of Command Interrupt Mask Bit Set to prevent EOCI flag from generating an MMC interrupt. C lear to allow EOCI flag to generate an MMC interrupt. End Of Frame Interrupt Mask Bit Set to prevent EOFI flag from generating an MMC interrupt. C lear to allow EOFI flag to generate an MMC interrupt. FIFO 2 Full Interrupt Mask Bit Set to prevent F2FI flag from generating an MMC interrupt. C lear to allow F2FI flag to generate an MMC interrupt. FIFO 1 Full Interrupt Mask Bit Set to prevent F1FI flag from generating an MMC interrupt. C lear to allow F1FI flag to generate an MMC interrupt. FIFO 2 Empty Interrupt Mask Bit Set to prevent F2EI flag from generating an MMC interrupt. C lear to allow F2EI flag to generate an MMC interrupt. FIFO 1 Empty Interrupt Mask Bit S et to prevent F1EI flag from generating an MMC interrupt. C lear to allow F1EI flag to generate an MMC interrupt. 7 MCBM 6 EORM 5 EOCM 4 EOFM 3 F2FM 2 F1FM 1 F2EM 0 F1EM Reset Value = 1111 1111b Table 18-14. MMCMD Register MMCMD (S:DDh) – MMC Command Register 7 MC7 6 MC6 Bit Mnemonic 5 MC5 4 MC4 3 MC3 2 MC2 1 MC1 0 MC0 Bit Number Description MMC Command Receive Byte Output (read) register of the response FIFO. MMC Command Transmit Byte Input (write) register of the command FIFO. 7-0 MC7:0 Reset Value = 1111 1111b 154 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B Table 18-15. MMDAT Register MMDAT (S:DCh) – MMC Data Register 7 MD7 6 MD6 Bit Mnemonic MD7:0 5 MD5 4 MD4 3 MD3 2 MD2 1 MD1 0 MD0 Bit Number 7-0 Description MMC Data Byte Input (write) or output (read) register of the data FIFO. Reset Value = 1111 1111b Table 18-16. MMCLK Register MMCLK (S:EDh) – MMC Clock Divider Register 7 MMCD7 6 MMCD6 Bit Mnemonic MMCD7:0 5 MMCD5 4 MMCD4 3 MMCD3 2 MMCD2 1 MMCD1 0 MMCD0 Bit Number 7-0 Description MMC Clock Divider 8-bit divider for MMC clock generation. Reset Value = 0000 0000b 155 4341F–MP3–03/06 19. Synchronous Peripheral Interface The AT8xC51SND2C implements a Synchronous Peripheral Interface with master and slave modes capability. Figure 19-1 shows an SPI bus configuration using the AT8xC51SND2C as master connected to slave peripherals while Figure 19-2 shows an SPI bus configuration using the AT8xC51SND2C as slave of an other master. The bus is made of three wires connecting all the devices together: • Master Output Slave Input (MOSI): it is used to transfer data in series from the master to a slave. It is driven by the master. • Master Input Slave Output (MISO): it is used to transfer data in series from a slave to the master. It is driven by the selected slave. Serial Clock (SCK): it is used to synchronize the data transmission 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. • Each slave peripheral is selected by one Slave Select pin (SS). If there is only one slave, it may be continuously selected with SS tied to a low level. Otherwise, the AT8xC51SND2C may select each device by software through port pins (Pn.x). Special care should be taken not to select 2 slaves at the same time to avoid bus conflicts. Figure 19-1. Typical Master SPI Bus Configuration Pn.z Pn.y Pn.x SS SO DataFlash 1 SI SCK SS DataFlash 2 SO SI SCK SS SO LCD Controller SI SCK AT8xC51SND2C P4.0 P4.1 P4.2 MISO MOSI SCK Figure 19-2. Typical Slave SPI Bus Configuration SSn SS1 SS0 SS SO SS Slave 1 SI SCK SS SO Slave 2 SI SCK AT8xC51SND2C Slave n MISO MOSI SCK MASTER MISO MOSI SCK 156 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B 19.1 Description The SPI controller interfaces with the C51 core through three special function registers: SPCON, the SPI control register (see Table 19-2); SPSTA, the SPI status register (see Table 19-3); and SPDAT, the SPI data register (see Table 19-4). 19.1.1 Master Mode The SPI operates in master mode when the MSTR bit in SPCON is set. Figure 19-3 shows the SPI block diagram in master mode. Only a master SPI module can initiate transmissions. Software begins the transmission by writing to SPDAT. Writing to SPDAT writes to the shift register while reading SPDAT reads an intermediate register updated at the end of each transfer. The Byte begins shifting out on the MOSI pin under the control of the bit rate generator. This generator also controls the shift register of the slave peripheral through the SCK output pin. As the Byte shifts out, another Byte shifts in from the slave peripheral on the MISO pin. The Byte is transmitted most significant bit (MSB) first. The end of transfer is signaled by SPIF being set. When the AT8xC51SND2C is the only master on the bus, it can be useful not to use SS# pin and get it back to I/O functionality. This is achieved by setting SSDIS bit in SPCON. Figure 19-3. SPI Master Mode Block Diagram MOSI/P4.1 MISO/P4.0 I 8-bit Shift Register SPDAT WR Q Internal Bus SCK/P4.2 SPDAT RD SS#/P4.3 MODF SSDIS SPCON.5 SPSTA.4 Control and Clock Logic WCOL SPSTA.6 PER CLOCK Bit Rate Generator SPEN SPCON.6 SPIF SPSTA.7 SPR2:0 SPCON CPHA SPCON.2 CPOL SPCON.3 Note: MSTR bit in SPCON is set to select master mode. 19.1.2 Slave Mode The SPI operates in slave mode when the MSTR bit in SPCON is cleared and data has been loaded in SPDAT. Figure 19-4 shows the SPI block diagram in slave mode. In slave mode, before a data transmission occurs, the SS pin of the slave SPI must be asserted to low level. SS must remain low until the transmission of the Byte is complete. In the slave SPI module, data enters the shift register through the MOSI pin under the control of the serial clock provided by the master SPI module on the SCK input pin. When the master starts a transmission, the data in the shift register begins shifting out on the MISO pin. The end of transfer is signaled by SPIF being set. 157 4341F–MP3–03/06 When the AT8xC51SND2C is the only slave on the bus, it can be useful not to use SS# pin and get it back to I/O functionality. This is achieved by setting SSDIS bit in SPCON. This bit has no effect when CPHA is cleared (see Section "SS Management", page 159). Figure 19-4. SPI Slave Mode Block Diagram MISO/P4.2 MOSI/P4.1 I 8-bit Shift Register SPDAT WR Q Internal Bus 20 MHz(2) 10000 5000 2500 1250 625 312.5 156.25 20000 FPER Divider 2 4 8 16 32 64 128 1 4341F–MP3–03/06 SCK/P4.2 Control and Clock Logic SS/P4.3 SSDIS SPCON.5 SPDAT RD SPIF SPSTA.7 CPHA SPCON.2 CPOL SPCON.3 Note: 1. MSTR bit in SPCON is cleared to select slave mode. 19.1.3 Bit Rate The bit rate can be selected from seven predefined bit rates using the SPR2, SPR1 and SPR0 control bits in SPCON according to Table 19-1. These bit rates are derived from the peripheral clock (FPER) issued from the Clock Controller block as detailed in Section "Oscillator", page 13. Table 19-1. Serial Bit Rates Bit Rate (kHz) Vs FPER SPR2 0 0 0 0 1 1 1 1 SPR1 0 0 1 1 0 0 1 1 SPR0 0 1 0 1 0 1 0 1 6 MHz(1) 3000 1500 750 375 187.5 93.75 46.875 6000 8 MHz(1) 4000 2000 1000 500 250 125 62.5 8000 10 MHz(1) 5000 2500 1250 625 312.5 156.25 78.125 10000 12 MHz(2) 6000 3000 1500 750 375 187.5 93.75 12000 16 MHz(2) 8000 4000 2000 1000 500 250 125 16000 Notes: 1. These frequencies are achieved in X1 mode, FPER = FOSC ÷ 2. 2. These frequencies are achieved in X2 mode, FPER = FOSC. 19.1.4 Data Transfer The Clock Polarity bit (CPOL in SPCON) defines the default SCK line level in idle state(1) while the Clock Phase bit (CPHA in SPCON) defines the edges on which the input data are sampled and the edges on which the output data are shifted (see Figure 19-5 and Figure 19-6). The SI signal is output from the selected slave and the SO signal is the output from the master. The AT8xC51SND2C captures data from the SI line while the selected slave captures data from the SO line. 158 AT8xC51SND2C/MP3B AT8xC51SND2C/MP3B For simplicity, Figure 19-5 and Figure 19-6 depict the SPI waveforms in idealized form and do n ot provide precise timing information. For timing parameters refer to the Section “AC Characteristics”. Note: 1. When the peripheral is disabled (SPEN = 0), default SCK line is high level. Figure 19-5. 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) MSB bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 LSB MISO (From Slave) MSB bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 LSB SS (to slave) Capture point Figure 19-6. Data Transmission Format (CPHA = 1) SCK cycle number SPEN (internal) 1 2 3 4 5 6 7 8 SCK (CPOL = 0) SCK (CPOL = 1) MOSI (from master) MSB bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 LSB MISO (from slave) MSB bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 LSB SS (to slave) Capture point 19.1.5 SS Management Figure 19-5 shows an SPI transmission with CPHA = 0, where the first SCK edge is the MSB capture point. Therefore the slave starts to output its MSB as soon as it is selected: SS asserted to low level. SS must then be deasserted between each Byte transmission (see Figure 19-7). SPDAT must be loaded with a data before SS is asserted again. Figure 19-6 shows an SPI transmission with CPHA = 1, where the first SCK edge is used by the slave as a start of transmission signal. Therefore, SS may remain asserted between each Byte transmission (see Figure 19-7). 159 4341F–MP3–03/06 Figure 19-7. SS Timing Diagram SI/SO SS (CPHA = 0) SS (CPHA = 1) Byte 1 Byte 2 Byte 3 19.1.6 Error Conditions The following flags signal the SPI error conditions: • MODF in SPSTA signals a mode fault. MODF flag is relevant only in master mode when SS usage is enabled (SSDIS bit cleared). It signals when set that an other master on the bus has asserted SS pin and so, may create a conflict on the bus with 2 master sending data at the same time. • A mode fault automatically disables the SPI (SPEN cleared) and configures the SPI in slave mode (MSTR cleared). MODF flag can trigger an interrupt as explained in Section "Interrupt", page 160. MODF flag is cleared by reading SPSTA and re-configuring SPI by writing to SPCON. WCOL in SPSTA signals a write collision. WCOL flag is set when SPDAT is loaded while a transfer is on-going. In this case data is not written to SPDAT and transfer continue uninterrupted. WCOL flag does not trigger any interrupt and is relevant jointly with SPIF flag. WCOL flag is cleared after reading SPSTA and writing new data to SPDAT while no transfer is on-going. • 19.2 Interrupt The SPI handles 2 interrupt sources that are the “end of transfer” and the “mode fault” flags. As shown in Figure 19-8, these flags are combined toghether to appear as a single interrupt source for the C51 core. The SPIF flag is set at the end of an 8-bit shift in and out and is cleared by reading SPSTA and then reading from or writing to SPDAT. The MODF flag is set in case of mode fault error and is cleared by reading SPSTA and then writing to SPCON. The SPI interrupt is enabled by setting ESPI bit in IEN1 register. This assumes interrupts are globally enabled by setting EA bit in IEN0 register. Figure 19-8. SPI Interrupt System SPIF SPSTA.7 SPI Controller Interrupt Request ESPI IEN1.2 MODF SPSTA.4 19.3 Configuration The SPI configuration is made through SPCON. 19.3.1 Master Configuration The SPI operates in master mode when the MSTR bit in SPCON is set. 160 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B 19.3.2 Slave Configuration The SPI operates in slave mode when the MSTR bit in SPCON is cleared and data has been loaded is SPDAT. 19.3.3 Data Exchange There are 2 possible methods to exchange data in master and slave modes: • polling • 19.3.4 interrupts Master Mode with Polling Policy Figure 19-9 shows the initialization phase and the transfer phase flows using the polling method. Using this flow prevents any overrun error occurrence. T he bit rate is selected according to Table 19-1. The transfer format depends on the slave peripheral. SS may be deasserted between transfers depending also on the slave peripheral. SPIF flag is cleared when reading SPDAT (SPSTA has been read before by the “end of transfer” check). This polling method provides the fastest effective transmission and is well adapted when communicating at high speed with other microcontrollers. However, the procedure may then be interrupted at any time by higher priority tasks. 161 4341F–MP3–03/06 Figure 19-9. Master SPI Polling Flows SPI Initialization Polling Policy SPI Transfer Polling Policy Disable interrupt SPIE = 0 Select Slave Pn.x = L Select Master Mode MSTR = 1 Start Transfer write data in SPDAT Select Bit Rate program SPR2:0 End Of Transfer? SPIF = 1? Select Format program CPOL & CPHA Get Data Received read SPDAT Enable SPI SPEN = 1 Last Transfer? Deselect Slave Pn.x = H 19.3.5 Master Mode with Interrupt F igure 19-10 shows the initialization phase and the transfer phase flows using the interrupt. Using this flow prevents any overrun error occurrence. The bit rate is selected according to Table 19-1. The transfer format depends on the slave peripheral. SS may be deasserted between transfers depending also on the slave peripheral. Reading SPSTA at the beginning of the ISR is mandatory for clearing the SPIF flag. Clear is effective when reading SPDAT. 162 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B Figure 19-10. Master SPI Interrupt Flows SPI Initialization Interrupt Policy SPI Interrupt Service Routine Select Master Mode MSTR = 1 Read Status Read SPSTA Select Bit Rate program SPR2:0 Get Data Received read SPDAT Select Format program CPOL & CPHA Start New Transfer write data in SPDAT Enable interrupt ESPI =1 Last Transfer? Enable SPI SPEN = 1 Deselect Slave Pn.x = H Select Slave Pn.x = L Disable interrupt SPIE = 0 Start Transfer write data in SPDAT 19.3.6 Slave Mode with Polling Policy Figure 19-11 shows the initialization phase and the transfer phase flows using the polling. The transfer format depends on the master controller. SPIF flag is cleared when reading SPDAT (SPSTA has been read before by the “end of reception” check). This provides the fastest effective transmission and is well adapted when communicating at high speed with other Microcontrollers. However, the process may then be interrupted at any time by higher priority tasks. 163 4341F–MP3–03/06 Figure 19-11. Slave SPI Polling Flows SPI Initialization Polling Policy SPI Transfer Polling Policy Disable interrupt SPIE = 0 Data Received? SPIF = 1? Select Slave Mode MSTR = 0 Get Data Received read SPDAT Select Format program CPOL & CPHA Prepare Next Transfer write data in SPDAT Enable SPI SPEN = 1 Prepare Transfer write data in SPDAT 19.3.7 Slave Mode with Interrupt Policy Figure 19-10 shows the initialization phase and the transfer phase flows using the interrupt. The transfer format depends on the master controller. Reading SPSTA at the beginning of the ISR is mandatory for clearing the SPIF flag. Clear is effective when reading SPDAT. 164 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B Figure 19-12. Slave SPI Interrupt Policy Flows SPI Initialization Interrupt Policy SPI Interrupt Service Routine Select Slave Mode MSTR = 0 Get Status Read SPSTA Select Format program CPOL & CPHA Get Data Received read SPDAT Enable interrupt ESPI =1 Prepare New Transfer write data in SPDAT Enable SPI SPEN = 1 Prepare Transfer write data in SPDAT 165 4341F–MP3–03/06 19.4 Registers Table 19-2. SPCON Register SPCON (S:C3h) – SPI Control Register 7 SPR2 6 SPEN Bit Mnemonic SPR2 5 SSDIS 4 MSTR 3 CPOL 2 CPHA 1 SPR1 0 SPR0 Bit Number 7 Description SPI Rate Bit 2 R efer to Table 19-1 for bit rate description. SPI Enable Bit S et to enable the SPI interface. C lear to disable the SPI interface. Slave Select Input Disable Bit Set to disable SS in both master and slave modes. In slave mode this bit has no effect if CPHA = 0. C lear to enable SS in both master and slave modes. Master Mode Select Set to select the master mode. C lear to select the slave mode. SPI Clock Polarity Bit(1) 6 SPEN 5 SSDIS 4 MSTR 3 CPOL Set to have the clock output set to high level in idle state. C lear to have the clock output set to low level in idle state. SPI Clock Phase Bit Set to have the data sampled when the clock returns to idle state (see CPOL). C lear to have the data sampled when the clock leaves the idle state (see CPOL). SPI Rate Bits 0 and 1 R efer to Table 19-1 for bit rate description. 2 CPHA 1-0 SPR1:0 Reset Value = 0001 0100b Note: 1. When the SPI is disabled, SCK outputs high level. 166 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B Table 19-3. SPSTA Register SPSTA (S:C4h) – SPI Status Register 7 SPIF 6 WCOL Bit Mnemonic 5 4 MODF 3 2 1 0 - Bit Number Description SPI Interrupt Flag Set by hardware when an 8-bit shift is completed. C leared by hardware when reading or writing SPDAT after reading SPSTA. Write Collision Flag Set by hardware to indicate that a collision has been detected. C leared by hardware to indicate that no collision has been detected. Reserved The value read from this bit is indeterminate. Do not set this bit. Mode Fault Set by hardware to indicate that the SS pin is at an appropriate level. C leared by hardware to indicate that the SS pin is at an inappropriate level. Reserved The value read from these bits is indeterminate. Do not set these bits. 7 SPIF 6 WCOL 5 - 4 MODF 3-0 - Reset Value = 00000 0000b Table 19-4. SPDAT Register SPDAT (S:C5h) – Synchronous Serial Data Register 7 SPD7 6 SPD6 Bit Mnemonic SPD7:0 5 SPD5 4 SPD4 3 SPD3 2 SPD2 1 SPD1 0 SPD0 Bit Number 7-0 Description Synchronous Serial Data. Reset Value = XXXX XXXXb 167 4341F–MP3–03/06 20. Serial I/O Port The serial I/O port in the AT8xC51SND2C provides both synchronous and asynchronous communication modes. It operates as a Synchronous Receiver and Transmitter in one single mode (Mode 0) and operates as an Universal Asynchronous Receiver and Transmitter (UART) in three full-duplex modes (Modes 1, 2 and 3). Asynchronous modes support framing error detection and multiprocessor communication with automatic address recognition. 20.1 Mode Selection SM0 and SM1 bits in SCON register (see Figure 20-3) are used to select a mode among the single synchronous and the three asynchronous modes according to Table 20-1. Table 20-1. SM0 0 0 1 1 Serial I/O Port Mode Selection SM1 0 1 0 1 Mode 0 1 2 3 Description Synchronous Shift Register 8-bit UART 9-bit UART 9-bit UART Baud Rate Fixed/Variable Variable Fixed Variable 20.2 Baud Rate Generator Depending on the mode and the source selection, the baud rate can be generated from either the Timer 1 or the Internal Baud Rate Generator. The Timer 1 can be used in Modes 1 and 3 while the Internal Baud Rate Generator can be used in Modes 0, 1 and 3. The addition of the Internal Baud Rate Generator allows freeing of the Timer 1 for other purposes in the application. It is highly recommended to use the Internal Baud Rate Generator as it allows higher and more accurate baud rates than Timer 1. Baud rate formulas depend on the modes selected and are given in the following mode sections. 20.2.1 Timer 1 When using Timer 1, the Baud Rate is derived from the overflow of the timer. As shown in F igure 20-1 Timer 1 is used in its 8-bit auto-reload mode (detailed in Section "Mode 2 (8-bit Timer with Auto-Reload)", page 54). SMOD1 bit in PCON register allows doubling of the generated baud rate. 168 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B Figure 20-1. Timer 1 Baud Rate Generator Block Diagram PER CLOCK ÷6 0 1 TL1 (8 bits) Overflow ÷2 0 1 T1 C/T1# TMOD.6 To serial Port INT1 GATE1 TMOD.7 SMOD1 PCON.7 TH1 (8 bits) T1 CLOCK TR1 TCON.6 20.2.2 Internal Baud Rate Generator When using the Internal Baud Rate Generator, the Baud Rate is derived from the overflow of the timer. As shown in Figure 20-2 the Internal Baud Rate Generator is an 8-bit auto-reload timer fed by the peripheral clock or by the peripheral clock divided by 6 depending on the SPD bit in BDRCON register (see Table 20-7). The Internal Baud Rate Generator is enabled by setting BBR bit in BDRCON register. SMOD1 bit in PCON register allows doubling of the generated baud rate. Figure 20-2. Internal Baud Rate Generator Block Diagram PER CLOCK ÷6 0 1 BRG (8 bits) BRR BDRCON.4 Overflow ÷2 0 1 To serial Port SPD BDRCON.1 BRL (8 bits) To serial Port (M0) IBRG0 CLOCK SMOD1 PCON.7 IBRG CLOCK 20.3 Synchronous Mode (Mode 0) Mode 0 is a half-duplex, synchronous mode, which is commonly used to expand the I/0 capabilities of a device with shift registers. The transmit data (TXD) pin outputs a set of eight clock pulses while the receive data (RXD) pin transmits or receives a Byte of data. The 8-bit data are transmitted and received least-significant bit (LSB) first. Shifts occur at a fixed Baud Rate (see Section "Baud Rate Selection (Mode 0)", page 171). Figure 20-3 shows the serial port block diagram in Mode 0. 169 4341F–MP3–03/06 Figure 20-3. Serial I/O Port Block Diagram (Mode 0) SCON.6 SCON.7 SM1 SM0 SBUF Tx SR RXD Mode Decoder M3 M2 M1 M0 SBUF Rx SR Mode Controller PER CLOCK TI SCON.1 RI SCON.0 BRG CLOCK Baud Rate Controller TXD 20.3.1 Transmission (Mode 0) To start a transmission mode 0, write to SCON register clearing bits SM0, SM1. As shown in Figure 20-4, writing the Byte to transmit to SBUF register starts the transmission. Hardware shifts the LSB (D0) onto the RXD pin during the first clock cycle composed of a high level then low level signal on TXD. During the eighth clock cycle the MSB (D7) is on the RXD pin. Then, hardware drives the RXD pin high and asserts TI to indicate the end of the transmission. Figure 20-4. Transmission Waveforms (Mode 0) TXD Write to SBUF RXD TI D0 D1 D2 D3 D4 D5 D6 D7 20.3.2 Reception (Mode 0) To start a reception in mode 0, write to SCON register clearing SM0, SM1 and RI bits and setting the REN bit. As shown in Figure 20-5, Clock is pulsed and the LSB (D0) is sampled on the RXD pin. The D0 bit is then shifted into the shift register. After eight samplings, the MSB (D7) is shifted into the shift register, and hardware asserts RI bit to indicate a completed reception. Software can then read the received Byte from SBUF register. Figure 20-5. Reception Waveforms (Mode 0) TXD Write to SCON RXD RI Set REN, Clear RI D0 D1 D2 D3 D4 D5 D6 D7 170 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B 20.3.3 Baud Rate Selection (Mode 0) In mode 0, the baud rate can be either, fixed or variable. As shown in Figure 20-6, the selection is done using M0SRC bit in BDRCON register. Figure 20-7 gives the baud rate calculation formulas for each baud rate source. Figure 20-6. Baud Rate Source Selection (mode 0) PER CLOCK IBRG0 CLOCK ÷6 0 To Serial Port 1 M0SRC BDRCON.0 Figure 20-7. Baud Rate Formulas (Mode 0) Baud_Rate= Baud_Rate FPER 6 FPER 6(1-SPD) ⋅ 16 ⋅ (256 -BRL) a. Fixed Formula b. Variable Formula 20.4 Asynchronous Modes (Modes 1, 2 and 3) The Serial Port has one 8-bit and 2 9-bit asynchronous modes of operation. Figure 20-8 shows the Serial Port block diagram in such asynchronous modes. Figure 20-8. Serial I/O Port Block Diagram (Modes 1, 2 and 3) SCON.6 SCON.7 SCON.3 SM1 SM0 Mode Decoder M3 M2 M1 M0 T1 CLOCK IBRG CLOCK PER CLOCK SBUF Tx SR Rx SR Mode & Clock Controller SBUF Rx SM2 SCON.4 TI SCON.1 RI SCON.0 20.4.0.1 Mode 1 Mode 1 is a full-duplex, asynchronous mode. The data frame (see Figure 20-9) consists of 10 bits: one start, eight data bits and one stop bit. Serial data is transmitted on the TXD pin and received on the RXD pin. When a data is received, the stop bit is read in the RB8 bit in SCON register. 4341F–MP3–03/06 - BRL= 256 FPER 6(1-SPD) ⋅ 16 ⋅ Baud_Rate = TB8 TXD RXD RB8 SCON.2 171 Figure 20-9. Data Frame Format (Mode 1) Mode 1 Start bit D0 D1 D2 D3 D4 D5 D6 D7 Stop bit 8-bit data 20.4.0.2 Modes 2 and 3 Modes 2 and 3 are full-duplex, asynchronous modes. The data frame (see Figure 20-10) consists of 11 bits: one start bit, eight data bits (transmitted and received LSB first), one programmable ninth data bit and one stop bit. Serial data is transmitted on the TXD pin and received on the RXD pin. On receive, the ninth bit is read from RB8 bit in SCON register. On transmit, the ninth data bit is written to TB8 bit in SCON register. Alternatively, you can use the ninth bit can be used as a command/data flag. Figure 20-10. Data Frame Format (Modes 2 and 3) D0 Start bit D1 D2 D3 D4 9-bit data D5 D6 D7 D8 Stop bit 20.4.1 Transmission (Modes 1, 2 and 3) To initiate a transmission, write to SCON register, set the SM0 and SM1 bits according to Table 20-1, and set the ninth bit by writing to TB8 bit. Then, writing the Byte to be transmitted to SBUF register starts the transmission. 20.4.2 Reception (Modes 1, 2 and 3) To prepare for reception, write to SCON register, set the SM0 and SM1 bits according to Table 20-1, and set the REN bit. The actual reception is then initiated by a detected high-to-low transition on the RXD pin. 20.4.3 Framing Error Detection (Modes 1, 2 and 3) Framing error detection is provided for the three asynchronous modes. To enable the framing bit error detection feature, set SMOD0 bit in PCON register as shown in Figure 20-11. 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 2 devices. If a valid stop bit is not found, the software sets FE bit in SCON register. Software may examine FE bit after each reception to check for data errors. Once set, only software or a chip reset clear FE bit. Subsequently received frames with valid stop bits cannot clear FE bit. When the framing error detection feature is enabled, RI rises on stop bit instead of the last data bit as detailed in Figure 20-17. Figure 20-11. Framing Error Block Diagram Framing Error Controller FE 1 SM0/FE 0 SCON.7 SM0 SMOD0 PCON.6 172 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B 20.4.4 Baud Rate Selection (Modes 1 and 3) In modes 1 and 3, the Baud Rate is derived either from the Timer 1 or the Internal Baud Rate Generator and allows different baud rate in reception and transmission. As shown in Figure 20-12 the selection is done using RBCK and TBCK bits in BDRCON register. Figure 20-13 gives the baud rate calculation formulas for each baud rate source while Table 202 details Internal Baud Rate Generator configuration for different peripheral clock frequencies and giving baud rates closer to the standard baud rates. Figure 20-12. Baud Rate Source Selection (Modes 1 and 3) T1 CLOCK IBRG CLOCK T1 CLOCK IBRG CLOCK 0 1 ÷ 16 To Serial Rx Port 0 1 ÷ 16 To Serial Tx Port RBCK BDRCON.2 TBCK BDRCON.3 Figure 20-13. Baud Rate Formulas (Modes 1 and 3) Baud_Rate= 2SMOD1 ⋅ FPER 6(1-SPD) ⋅ 32 ⋅ (256 -BRL) 2SMOD1 ⋅ FPER ⋅ 32 ⋅ Baud_Rate Baud_Rate= 2SMOD1 ⋅ FPER 6 ⋅ 32 ⋅ ( 256 -TH1) 2SMOD1 ⋅ FPER 192 ⋅ Baud_Rate BRL= 256 - 6 (1-SPD) TH1= 256 - a. IBRG Formula b. T1 Formula 173 4341F–MP3–03/06 Table 20-2. Internal Baud Rate Generator Value FPER = 6 MHz(1) FPER = 8 MHz(1) Error % 2.34 2.34 0.16 0.16 SPD 1 1 1 1 1 SMOD 1 1 1 1 1 1 BRL 247 243 230 204 152 Error % 3.55 0.16 0.16 0.16 0.16 SPD 1 1 1 1 1 FPER = 10 MHz(1) SMOD 1 1 1 1 1 1 BRL 245 240 223 191 126 Error % 1.36 1.73 1.36 0.16 0.16 Baud Rate 115200 57600 38400 19200 9600 4800 SPD 1 1 1 1 SMOD 1 1 1 1 1 BRL 246 236 217 178 FPER = 12 MHz(2) Baud Rate 115200 57600 38400 19200 9600 4800 SPD 1 1 1 1 1 SMOD 1 1 1 1 1 1 BRL 243 236 217 178 100 Error % 0.16 2.34 0.16 0.16 0.16 SPD 1 1 1 1 1 1 FPER = 16 MHz(2) SMOD 1 1 1 1 1 1 1 BRL 247 239 230 204 152 48 Error % 3.55 2.12 0.16 0.16 0.16 0.16 SPD 1 1 1 1 1 1 FPER = 20 MHz(2) SMOD 1 1 1 1 1 1 0 BRL 245 234 223 191 126 126 Error % 1.36 1.36 1.36 0.16 0.16 0.16 Notes: 1. These frequencies are achieved in X1 mode, FPER = F OSC ÷ 2. 2. These frequencies are achieved in X2 mode, FPER = F OSC. 20.4.5 Baud Rate Selection (Mode 2) In mode 2, the baud rate can only be programmed to 2 fixed values: 1/16 or 1/32 of the peripheral clock frequency. As shown in Figure 20-14 the selection is done using SMOD1 bit in PCON register. Figure 20-15 gives the baud rate calculation formula depending on the selection. Figure 20-14. Baud Rate Generator Selection (Mode 2) PER CLOCK ÷2 0 1 ÷ 16 To Serial Port SMOD1 PCON.7 174 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B Figure 20-15. Baud Rate Formula (Mode 2) Baud_Rate= 2SMOD1 ⋅ FPER 32 20.5 Multiprocessor Communication (Modes 2 and 3) Modes 2 and 3 provide a ninth-bit mode to facilitate multiprocessor communication. To enable this feature, set SM2 bit in SCON register. When the multiprocessor communication feature is enabled, the serial Port can differentiate between data frames (ninth bit clear) and address frames (ninth bit set). This allows the AT8xC51SND2C to function as a slave processor in an environment where multiple slave processors share a single serial line. When the multiprocessor communication feature is enabled, the receiver ignores frames with the ninth bit clear. The receiver examines frames with the ninth bit set for an address match. If the received address matches the slaves address, the receiver hardware sets RB8 and RI bits in SCON register, generating an interrupt. The addressed slave’s software then clears SM2 bit in SCON register and prepares to receive the data Bytes. The other slaves are unaffected by these data Bytes because they are waiting to respond to their own addresses. 20.6 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, the automatic address recognition feature in mode 1 may be enabled. 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). 20.6.1 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: SADDR = 0101 0110b SADEN = 1111 1100b Given = 0101 01XXb The following is an example of how to use given addresses to address different slaves: Slave A:SADDR = 1111 0001b 175 4341F–MP3–03/06 SADEN = 1111 1010b Given = 1111 0X0Xb Slave B:SADDR = 1111 0011b SADEN = 1111 1001b Given = 1111 0XX1b Slave C:SADDR = 1111 0011b SADEN = 1111 1101b Given = 1111 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 0; for slaves B and C, bit 1 is a don’t care bit. To communicate with slaves A and B, but not slave C, 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). 20.6.2 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.: SADDR = 0101 0110b SADEN = 1111 1100b (SADDR | SADEN)=1111 111Xb The use of don’t-care bits provides flexibility in defining the broadcast address, however in most applications, a broadcast address is FFh. The following is an example of using broadcast addresses: Slave A:SADDR = 1111 0001b SADEN = 1111 1010b Given = 1111 1X11b, Slave B:SADDR = 1111 0011b SADEN = 1111 1001b Given = 1111 1X11b, Slave C:SADDR = 1111 0010b SADEN = 1111 1101b Given = 1111 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 the address FFh. To communicate with slaves A and B, but not slave C, the master must send the address FBh. 20.6.3 Reset Address 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 is backwards compatible with the 80C51 microcontrollers that do not support automatic address recognition. 176 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B 20.7 Interrupt The Serial I/O Port handles 2 interrupt sources that are the “end of reception” (RI in SCON) and “end of transmission” (TI in SCON) flags. As shown in Figure 20-16 these flags are combined together to appear as a single interrupt source for the C51 core. Flags must be cleared by software when executing the serial interrupt service routine. The serial interrupt is enabled by setting ES bit in IEN0 register. This assumes interrupts are globally enabled by setting EA bit in IEN0 register. Depending on the selected mode and weather the framing error detection is enabled or disabled, RI flag is set during the stop bit or during the ninth bit as detailed in Figure 20-17. Figure 20-16. Serial I/O Interrupt System SCON.0 RI Serial I/O Interrupt Request TI SCON.1 ES IEN0.4 Figure 20-17. Interrupt Waveforms a. Mode 1 RXD Start Bit RI SMOD0 = X FE SMOD0 = 1 b. Mode 2 and 3 RXD Start bit RI SMOD0 = 0 RI SMOD0 = 1 FE SMOD0 = 1 D0 D1 D2 D3 D4 9-bit data D5 D6 D7 D8 Stop bit D0 D1 D2 D3 D4 D5 D6 D7 Stop Bit 8-bit Data 177 4341F–MP3–03/06 20.8 Registers Table 20-3. SCON Register SCON (S:98h) – Serial Control Register 7 FE/SM0 6 OVR/SM1 Bit Mnemonic 5 SM2 4 REN 3 TB8 2 RB8 1 TI 0 RI Bit Number Description Framing Error Bit To select this function, set SMOD0 bit in PCON register. Set by hardware to indicate an invalid stop bit. Must be cleared by software. Serial Port Mode Bit 0 R efer to Table 20-1 for mode selection. Serial Port Mode Bit 1 R efer to Table 20-1 for mode selection. Serial Port Mode Bit 2 Set to enable the multiprocessor communication and automatic address recognition features. C lear to disable the multiprocessor communication and automatic address recognition features. Receiver Enable Bit Set to enable reception. C lear to disable reception. Transmit Bit 8 Modes 0 and 1: Not used. Modes 2 and 3: Software writes the ninth data bit to be transmitted to TB8. Receiver Bit 8 Mode 0: Not used. Mode 1 (SM2 cleared): Set or cleared by hardware to reflect the stop bit received. Modes 2 and 3 (SM2 set): Set or cleared by hardware to reflect the ninth bit received. Transmit Interrupt Flag Set by the transmitter after the last data bit is transmitted. Must be cleared by software. Receive Interrupt Flag Set by the receiver after the stop bit of a frame has been received. Must be cleared by software. FE 7 SM0 6 SM1 5 SM2 4 REN 3 TB8 2 RB8 1 TI 0 RI Reset Value = 0000 0000b 178 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B Table 20-4. SBUF Register SBUF (S:99h) – Serial Buffer Register 7 SD7 6 SD6 Bit Mnemonic 5 SD5 4 SD4 3 SD3 2 SD2 1 SD1 0 SD0 Bit Number Description Serial Data Byte R ead the last data received by the serial I/O Port. Write the data to be transmitted by the serial I/O Port. 7-0 SD7:0 Reset value = XXXX XXXXb Table 20-5. SADDR Register SADDR (S:A9h) – Slave Individual Address Register 7 SAD7 6 SAD6 Bit Mnemonic SAD7:0 5 SAD5 4 SAD4 3 SAD3 2 SAD2 1 SAD1 0 SAD0 Bit Number 7-0 Description Slave Individual Address Reset Value = 0000 0000b Table 20-6. SADEN Register SADEN (S:B9h) – Slave Individual Address Mask Byte Register 7 SAE7 6 SAE6 Bit Mnemonic SAE7:0 5 SAE5 4 SAE4 3 SAE3 2 SAE2 1 SAE1 0 SAE0 Bit Number 7-0 Description Slave Address Mask Byte Reset Value = 0000 0000b 179 4341F–MP3–03/06 Table 20-7. BDRCON Register BDRCON (S:92h) – Baud Rate Generator Control Register 7 6 Bit Mnemonic 5 4 BRR 3 TBCK 2 RBCK 1 SPD 0 M0SRC Bit Number 7-5 Description Reserved The value read from these bits are indeterminate. Do not set these bits. Baud Rate Run Bit Set to enable the baud rate generator. C lear to disable the baud rate generator. Transmission Baud Rate Selection Bit Set to select the baud rate generator as transmission baud rate generator. C lear to select the Timer 1 as transmission baud rate generator. Reception Baud Rate Selection Bit Set to select the baud rate generator as reception baud rate generator. C lear to select the Timer 1 as reception baud rate generator. Baud Rate Speed Bit Set to select high speed baud rate generation. C lear to select low speed baud rate generation. Mode 0 Baud Rate Source Bit Set to select the variable baud rate generator in Mode 0. C lear to select fixed baud rate in Mode 0. 4 BRR 3 TBCK 2 RBCK 1 SPD 0 M0SRC Reset Value = XXX0 0000b Table 20-8. BRL Register BRL (S:91h) – Baud Rate Generator Reload Register 7 BRL7 6 BRL6 Bit Mnemonic BRL7:0 5 BRL5 4 BRL4 3 BRL3 2 BRL2 1 BRL1 0 BRL0 Bit Number 7-0 Description Baud Rate Reload Value Reset Value = 0000 0000b 180 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B 21. Two-wire Interface (TWI) Controller The AT8xC51SND2C implements a TWI controller supporting the four standard master and slave modes with multimaster capability. Thus, it allows connection of slave devices like LCD controller, audio DAC, etc., but also external master controlling where the AT8xC51SND2C is used as a peripheral of a host. The TWI bus is a bi-directional TWI serial communication standard. It is designed primarily for simple but efficient integrated circuit control. The system is comprised of 2 lines, SCL (Serial Clock) and SDA (Serial Data) that carry information between the ICs connected to them. The serial data transfer is limited to 100 Kbit/s in low speed mode, however, some higher bit rates can be achieved depending on the oscillator frequency. Various communication configurations can be designed using this bus. Figure 21-1 s hows a typical TWI bus configuration using the AT8xC51SND2C in master and slave modes. All the devices connected to the bus can be master and slave. Figure 21-1. Typical TWI Bus Configuration AT8xC51SND2C Master/Slave Rp SCL SDA Rp SCL SDA LCD Display Audio DAC HOST Microprocessor 21.1 Description The CPU interfaces to the TWI logic via the following four 8-bit special function registers: the Synchronous Serial Control register (SSCON SFR, see Table 21-9), the Synchronous Serial D ata register (SSDAT SFR, see Table 21-11), the Synchronous Serial Status register (SSSTA S FR, see T able 2 1-10 ) and the Synchronous Serial Address register (SSADR SFR, see Table 21-12). SSCON is used to enable the controller, to program the bit rate (see Table 21-9), to enable slave modes, to acknowledge or not a received data, to send a START or a STOP condition on the TWI bus, and to acknowledge a serial interrupt. A hardware reset disables the TWI controller. SSSTA contains a status code which reflects the status of the TWI logic and the TWI 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 SSSTA contains F8h, no relevant state information is available and no serial interrupt is requested. A valid status code is available in SSSTA after SSI is set by hardware and is still present until SSI has been reset by software. Table 21-2 to Table 21-6 give the status for both master and slave 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 TWI logic is in a defined state and the serial interrupt flag is set. Data in SSDAT remains stable as long as SSI 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 controller will respond when programmed as a slave transmitter or receiver. The LSB is used to enable general call address (00h) recognition. Figure 21-2 shows how a data transfer is accomplished on the TWI bus. 181 4341F–MP3–03/06 Figure 21-2. Complete Data Transfer on TWI Bus SDA MSB Slave Address R/W ACK direction signal bit from receiver 8 9 1 Nth data Byte ACK signal from receiver 8 9 P/S SCL S 1 2 2 Clock Line Held Low While Serial Interrupts Are Serviced The four operating modes are: • • • • Master transmitter Master receiver Slave transmitter Slave receiver Data transfer in each mode of operation are shown in Figure 21-3 through Figure 21-6. These figures contain the following abbreviations: A A Data S P MR MT SLA GCA R W Acknowledge bit (low level at SDA) Not acknowledge bit (high level on SDA) 8-bit data Byte START condition STOP condition Master Receive Master Transmit Slave Address General Call Address (00h) Read bit (high level at SDA) Write bit (low level at SDA) In Figure 21-3 through Figure 21-6, circles are used to indicate when the serial interrupt flag is set. The numbers in the circles show the status code held in SSSTA. 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 SSSTA 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 21-2 through Table 21-6. 21.1.1 Bit Rate The bit rate can be selected from seven predefined bit rates or from a programmable bit rate generator using the SSCR2, SSCR1, and SSCR0 control bits in SSCON (see Table 21-9). The predefined bit rates are derived from the peripheral clock (FPER) issued from the Clock Controller block as detailed in s ection "Oscillator", page 13, while bit rate generator is based on timer 1 overflow output. 182 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B Table 21-1. SSCRx 2 0 0 0 0 1 1 1 1 1 0 0 1 1 0 0 1 1 0 0 1 0 1 0 1 0 1 FPER = 6 MHz 47 53.5 62.5 75 12.5 100 200(1) 0.5 < ⋅ < 125 (1) Serial Clock Rates Bit Frequency (kHz) FPER = 8 MHz 62.5 71.5 83 100 16.5 133.3(1) 266.7(1) 0.67 < ⋅ < 166.7 (1) FPER = 10 MHz 78.125 89.3 104.2(1) 125(1) 20.83 166.7(1) 333.3(1) 0.81 < ⋅ < 208.3(1) FPER Divided By 128 112 96 80 480 60 30 96 ⋅ (256 – reload value Timer 1) Note: 1. These bit rates are outside of the low speed standard specification limited to 100 kHz but can be used with high speed TWI components limited to 400 kHz. 21.1.2 Master Transmitter Mode In the master transmitter mode, a number of data Bytes are transmitted to a slave receiver (see Figure 21-3). Before the master transmitter mode can be entered, SSCON must be initialized as follows: SSCR2 Bit Rate SSPE 1 SSSTA 0 SSSTO 0 SSI 0 SSAA X SSCR1 Bit Rate SSCR0 Bit Rate SSCR2:0 define the serial bit rate (see Table 21-1). SSPE must be set to enable the controller. SSSTA, SSSTO and SSI must be cleared. The master transmitter mode may now be entered by setting the SSSTA bit. The TWI logic will now monitor the TWI bus and generate a START condition as soon as the bus becomes free. When a START condition is transmitted, the serial interrupt flag (SSI bit in SSCON) is set, and the status code in SSSTA is 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). The serial interrupt flag (SSI) must then be cleared before the serial transfer can continue. When the slave address and the direction bit have been transmitted and an acknowledgment bit has been received, SSI is set again and a number of status code in SSSTA are possible. There are 18h, 20h or 38h for the master mode and also 68h, 78h or B0h if the slave mode was enabled (SSAA = logic 1). The appropriate action to be taken for each of these status code is detailed in Table 21-2. This scheme is repeated until a STOP condition is transmitted. SSPE and SSCR2:0 are not affected by the serial transfer and are not referred to in Table 21-2. After a repeated START condition (state 10h) the controller may switch to the master receiver mode by loading SSDAT with SLA+R. 21.1.3 Master Receiver Mode In the master receiver mode, a number of data Bytes are received from a slave transmitter (see Figure 21-4). 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 address and the data direction bit (SLA+R). The serial interrupt flag (SSI) must then be cleared before the serial transfer can continue. 183 4341F–MP3–03/06 W hen the slave address and the direction bit have been transmitted and an acknowledgment bit has been received, the serial interrupt flag is set again and a number of status code in SSSTA are possible. There are 40h, 48h or 38h for the master mode and also 68h, 78h or B0h if the slave mode was enabled (SSAA = logic 1). The appropriate action to be taken for each of these status code is detailed in T able 2 1-6 . This scheme is repeated until a STOP condition is transmitted. SSPE and SSCR2:0 are not affected by the serial transfer and are not referred to in Table 21-6. After a repeated START condition (state 10h) the controller may switch to the master transmitter mode by loading SSDAT with SLA+W. 21.1.4 Slave Receiver Mode In the slave receiver mode, a number of data Bytes are received from a master transmitter (see F igure 2 1-5). To initiate the slave receiver mode, SSADR and SSCON must be loaded as follows: SSA6 SSA5 SSA4 SSA3 Own Slave Address SSA2 SSA1 SSA0 SSGC X ←⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯ ⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯→ The upper 7 bits are the addresses to which the controller will respond when addressed by a master. If the LSB (SSGC) is set, the controller will respond to the general call address (00h); otherwise, it ignores the general call address. SSCR2 X SSPE 1 SSSTA 0 SSSTO 0 SSI 0 SSAA 1 SSCR1 X SSCR0 X SSCR2:0 have no effect in the slave mode. SSPE must be set to enable the controller. The SSAA bit must be set to enable the own slave address or the general call address acknowledgment. SSSTA, SSSTO and SSI must be cleared. When SSADR and SSCON have been initialized, the controller waits until it is addressed by its own slave address followed by the data direction bit which must be logic 0 (W) for operating in the slave receiver mode. After its own slave address and the W bit has been received, the serial interrupt flag is set and a valid status code can be read from SSSTA. This status code is used to vector to an interrupt service routine, and the appropriate action to be taken for each of these status code is detailed in Table 2 1-6 and Table 21-6 . The slave receiver mode may also be entered if arbitration is lost while the controller is in the master mode (see states 68h and 78h). If the SSAA bit is reset during a transfer, the controller will return a not acknowledge (logic 1) to SDA after the next received data Byte. While SSAA is reset, the controller does not respond to its own slave address. However, the TWI bus is still monitored and address recognition may be resumed at any time by setting SSAA. This means that the SSAA bit may be used to temporarily isolate the controller from the TWI bus. 21.1.5 Slave Transmitter Mode In the slave transmitter mode, a number of data Bytes are transmitted to a master receiver (see F igure 2 1-6 ). Data transfer is initialized as in the slave receiver mode. When SSADR and SSCON have been initialized, the controller waits until it is addressed by its own slave address followed by the data direction bit which must be logic 1 (R) for operating 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 SSSTA. This status code is used to vector to an interrupt service routine, and the appropriate action to be taken for each of these status code is detailed in Table 21-6. The slave transmitter mode may also be entered if arbitration is lost while the controller is in the master mode (see state B0h). 184 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B If the SSAA bit is reset during a transfer, the controller will transmit the last Byte of the transfer and enter state C0h or C8h. The controller 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 SSAA is reset, the controller does not respond to its own slave address. However, the TWI bus is still monitored and address recognition may be resumed at any time by setting SSAA. This means that the SSAA bit may be used to temporarily isolate the controller from the TWI bus. 21.1.6 Miscellaneous States There are 2 SSSTA codes that do not correspond to a defined TWI hardware state (see Table 21-7). These are discussed below. Status F8h indicates that no relevant information is available because the serial interrupt flag is not yet set. This occurs between other states and when the controller is not involved in a serial transfer. Status 00h indicates that a bus error has occurred during a 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 are during the serial transfer of an address Byte, a data Byte, or an acknowledge bit. When a bus error occurs, SSI is set. To recover from a bus error, the SSSTO flag must be set and SSI must be cleared. This causes the controller to enter the not addressed slave mode and to clear the SSSTO flag (no other bits in S1CON are affected). The SDA and SCL lines are released and no STOP condition is transmitted. Note: The TWI controller interfaces to the external TWI bus via 2 port 1 pins: P1.6/SCL (serial clock line) and P1.7/SDA (serial data line). To avoid low level asserting and conflict on these lines when the TWI controller is enabled, the output latches of P1.6 and P1.7 must be set to logic 1. 185 4341F–MP3–03/06 Figure 21-3. Format and States in the Master Transmitter Mode MT Successful transmission to a slave receiver S SLA W A Data A P 08h Next transfer started with a repeated start condition 18h 28h S SLA W 10h R Not acknowledge received after the slave address A P MR 20h Not acknowledge received after a data Byte A P 30h Arbitration lost in slave address or data Byte A or A Other master continues A or A Other master continues 38h Arbitration lost and addressed as slave A Other master continues 38h 68h 78h B0h To corresponding states in slave mode From master to slave From slave to master Data A Any number of data Bytes and their associated acknowledge bits This number (contained in SSSTA) corresponds to a defined state of the TWI bus nnh 186 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B Figure 21-4. Format and States in the Master Receiver Mode MR Successful reception from a slave transmitter S SLA R A Data A Data A P 08h Next transfer started with a repeated start condition 40h 50h 58h S SLA R 10h W Not acknowledge received after the slave address A P MT 48h Arbitration lost in slave address or data Byte A or A Other master continues A Other master continues 38h Arbitration lost and addressed as slave A Other master continues 38h 68h 78h B0h To corresponding states in slave mode From master to slave From slave to master Data A Any number of data Bytes and their associated acknowledge bits This number (contained in SSSTA) corresponds to a defined state of the TWI bus nnh 187 4341F–MP3–03/06 Figure 21-5. Format and States in the Slave Receiver Mode Reception of the own slave address and one or more data Bytes. All are acknowledged S SLA W A Data A Data A P or S 60h Last data Byte received is not acknowledged 80h 80h A A0h P or S 88h Arbitration lost as master and addressed as slave A 68h Reception of the general call address and one or more data Bytes General Call A Data A Data A P or S 70h Last data Byte received is not acknowledged 90h 90h A A0h P or S 98h Arbitration lost as master and addressed as slave by general call A 78h From master to slave From slave to master Data A Any number of data Bytes and their associated acknowledge bits This number (contained in SSSTA) corresponds to a defined state of the TWI bus nnh 188 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B Figure 21-6. Format and States in the Slave Transmitter Mode Reception of the own slave address and transmission of one or more data Bytes. S SLA R A Data A Data A P or S A8h Arbitration lost as master and addressed as slave A B8h C0h B0h Last data Byte transmitted. Switched to not addressed slave (SSAA = 0). A All 1’s P or S C8h From master to slave From slave to master Data A Any number of data Bytes and their associated acknowledge bits This number (contained in SSSTA) corresponds to a defined state of the TWI bus nnh 189 4341F–MP3–03/06 Table 21-2. Status Code SSSTA 08h Status for Master Transmitter Mode Application Software Response To SSCON Status of the TWI Bus and TWI Hardware To/From SSDAT A START condition has Write SLA+W been transmitted A repeated START condition has been transmitted Write SLA+W Write SLA+R SSSTA X SSSTO 0 SSI 0 SSAA X Next Action Taken by TWI Hardware SLA+W will be transmitted. SLA+W will be transmitted. SLA+R will be transmitted. Logic will switch to master receiver mode Data Byte will be transmitted. Repeated START will be transmitted. STOP condition will be transmitted and SSSTO flag will be reset. STOP condition followed by a START condition will be transmitted and SSSTO flag will be reset. Data Byte will be transmitted. Repeated START will be transmitted. STOP condition will be transmitted and SSSTO flag will be reset. STOP condition followed by a START condition will be transmitted and SSSTO flag will be reset. Data Byte will be transmitted. Repeated START will be transmitted. STOP condition will be transmitted and SSSTO flag will be reset. STOP condition followed by a START condition will be transmitted and SSSTO flag will be reset. Data Byte will be transmitted. Repeated START will be transmitted. STOP condition will be transmitted and SSSTO flag will be reset. STOP condition followed by a START condition will be transmitted and SSSTO flag will be reset. TWI bus will be released and not addressed slave mode will be entered. A START condition will be transmitted when the bus becomes free. X X 0 0 0 0 X X 10h Write data Byte 18h SLA+W has been transmitted; ACK has been received No SSDAT action No SSDAT action No SSDAT action 0 1 0 1 0 0 1 1 0 0 0 0 X X X X Write data Byte 20h SLA+W has been transmitted; NOT ACK has been received No SSDAT action No SSDAT action No SSDAT action 0 1 0 1 0 0 1 1 0 0 0 0 X X X X Write data Byte 28h Data Byte has been transmitted; ACK has been received No SSDAT action No SSDAT action No SSDAT action 0 1 0 1 0 0 1 1 0 0 0 0 X X X X Write data Byte 30h Data Byte has been transmitted; NOT ACK has been received No SSDAT action No SSDAT action No SSDAT action 0 1 0 1 0 0 1 1 0 0 0 0 X X X X 38h Arbitration lost in SLA+W or data Bytes No SSDAT action No SSDAT action 0 1 0 0 0 0 X X 190 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B Table 21-3. Status Code SSSTA 08h Status for Master Receiver Mode Application Software Response To SSCON Status of the TWI Bus and TWI Hardware To/From SSDAT A START condition has Write SLA+R been transmitted A repeated START condition has been transmitted Write SLA+R Write SLA+W SSSTA X SSSTO 0 SSI 0 SSAA X Next Action Taken by TWI Hardware SLA+R will be transmitted. SLA+R will be transmitted. SLA+W will be transmitted. Logic will switch to master transmitter mode. TWI bus will be released and not addressed slave mode will be entered. A START condition will be transmitted when the bus becomes free. Data Byte will be received and NOT ACK will be returned. Data Byte will be received and ACK will be returned. Repeated START will be transmitted. STOP condition will be transmitted and SSSTO flag will be reset. STOP condition followed by a START condition will be transmitted and SSSTO flag will be reset. Data Byte will be received and NOT ACK will be returned. Data Byte will be received and ACK will be returned. Repeated START will be transmitted. STOP condition will be transmitted and SSSTO flag will be reset. STOP condition followed by a START condition will be transmitted and SSSTO flag will be reset. X X 0 0 0 0 X X 10h 38h Arbitration lost in SLA+R or NOT ACK bit SLA+R has been transmitted; ACK has been received No SSDAT action No SSDAT action No SSDAT action No SSDAT action No SSDAT action No SSDAT action No SSDAT action Read data Byte Read data Byte Read data Byte Read data Byte Read data Byte 0 1 0 0 1 0 1 0 0 1 0 1 0 0 0 0 0 1 1 0 0 0 1 1 0 0 0 0 0 0 0 0 0 0 0 0 X X 0 1 X X X 0 1 X X X 40h 48h SLA+R has been transmitted; NOT ACK has been received 50h Data Byte has been received; ACK has been returned 58h Data Byte has been received; NOT ACK has been returned 191 4341F–MP3–03/06 Table 21-4. Status Code SSSTA Status for Slave Receiver Mode with Own Slave Address Application Software Response To SSCON Status of the TWI Bus and TWI Hardware To/From SSDAT Own SLA+W has been No SSDAT action received; ACK has been returned No SSDAT action Arbitration lost in SLA+R/W as master; own SLA+W has been received; ACK has been returned Previously addressed with own SLA+W; data has been received; ACK has been returned No SSDAT action No SSDAT action SSSTA X X X X SSSTO 0 0 0 0 SSI 0 0 0 0 SSAA 0 1 0 1 Next Action Taken by TWI Hardware Data Byte will be received and NOT ACK will be returned. Data Byte will be received and ACK will be returned. Data Byte will be received and NOT ACK will be returned. Data Byte will be received and ACK will be returned. 60h 68h Read data Byte Read data Byte X X 0 0 0 0 0 1 80h Data Byte will be received and NOT ACK will be returned. Data Byte will be received and ACK will be returned. Switched to the not addressed slave mode; no recognition of own SLA or GCA. Switched to the not addressed slave mode; own SLA will be recognized; GCA will be recognized if SSGC = logic 1. Switched to the not addressed slave mode; no recognition of own SLA or GCA. A START condition will be transmitted when the bus becomes free. Switched to the not addressed slave mode; own SLA will be recognized; GCA will be recognized if SSGC = logic 1. A START condition will be transmitted when the bus becomes free. Switched to the not addressed slave mode; no recognition of own SLA or GCA. Switched to the not addressed slave mode; own SLA will be recognized; GCA will be recognized if SSGC = logic 1. Switched to the not addressed slave mode; no recognition of own SLA or GCA. A START condition will be transmitted when the bus becomes free. Switched to the not addressed slave mode; own SLA will be recognized; GCA will be recognized if SSGC = logic 1. A START condition will be transmitted when the bus becomes free. Read data Byte Previously addressed with own SLA+W; data has been received; NOT ACK has been returned Read data Byte 0 0 0 0 0 0 0 1 88h Read data Byte 1 0 0 0 Read data Byte 1 0 0 1 No SSDAT action A STOP condition or repeated START condition has been received while still addressed as slave No SSDAT action 0 0 0 0 0 0 0 1 A0h No SSDAT action 1 0 0 0 No SSDAT action 1 0 0 1 192 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B Table 21-5. Status Code SSSTA Status for Slave Receiver Mode with General Call Address Application Software Response To SSCON Status of the TWI Bus and TWI Hardware To/From SSDAT General call address has been received; ACK has been returned Arbitration lost in SLA+R/W as master; general call address has been received; ACK has been returned Previously addressed with general call; data has been received; ACK has been returned No SSDAT action No SSDAT action SSSTA X X SSSTO 0 0 SSI 0 0 SSAA 0 1 Next Action Taken by TWI Hardware Data Byte will be received and NOT ACK will be returned. Data Byte will be received and ACK will be returned. 70h No SSDAT action No SSDAT action X X 0 0 0 0 0 1 78h Data Byte will be received and NOT ACK will be returned. Data Byte will be received and ACK will be returned. Read data Byte Read data Byte X X 0 0 0 0 0 1 90h Data Byte will be received and NOT ACK will be returned. Data Byte will be received and ACK will be returned. Switched to the not addressed slave mode; no recognition of own SLA or GCA. Switched to the not addressed slave mode; own SLA will be recognized; GCA will be recognized if SSGC = logic 1. Switched to the not addressed slave mode; no recognition of own SLA or GCA. A START condition will be transmitted when the bus becomes free. Switched to the not addressed slave mode; own SLA will be recognized; GCA will be recognized if SSGC = logic 1. A START condition will be transmitted when the bus becomes free. Switched to the not addressed slave mode; no recognition of own SLA or GCA. Switched to the not addressed slave mode; own SLA will be recognized; GCA will be recognized if SSGC = logic 1. Switched to the not addressed slave mode; no recognition of own SLA or GCA. A START condition will be transmitted when the bus becomes free. Switched to the not addressed slave mode; own SLA will be recognized; GCA will be recognized if SSGC = logic 1. A START condition will be transmitted when the bus becomes free. Read data Byte Previously addressed with general call; data has been received; NOT ACK has been returned Read data Byte 0 0 0 0 0 0 0 1 98h Read data Byte 1 0 0 0 Read data Byte 1 0 0 1 No SSDAT action A STOP condition or repeated START condition has been received while still addressed as slave No SSDAT action 0 0 0 0 0 0 0 1 A0h No SSDAT action 1 0 0 0 No SSDAT action 1 0 0 1 193 4341F–MP3–03/06 Table 21-6. Status Code SSSTA Status for Slave Transmitter Mode Application Software Response Status of the TWI Bus and TWI Hardware To/From SSDAT Own SLA+R has been received; ACK has been returned Arbitration lost in SLA+R/W as master; own SLA+R has been received; ACK has been returned Data Byte in SSDAT has been transmitted; ACK has been received Write data Byte Write data Byte Write data Byte Write data Byte SSSTA X X X X To SSCON SSSTO 0 0 0 0 SSI 0 0 0 0 SSAA 0 1 0 1 Next Action Taken by TWI Hardware Last data Byte will be transmitted. Data Byte will be transmitted. Last data Byte will be transmitted. Data Byte will be transmitted. A8h B0h Write data Byte Write data Byte X X 0 0 0 0 0 1 Last data Byte will be transmitted. Data Byte will be transmitted. Switched to the not addressed slave mode; no recognition of own SLA or GCA. Switched to the not addressed slave mode; own SLA will be recognized; GCA will be recognized if SSGC = logic 1. Switched to the not addressed slave mode; no recognition of own SLA or GCA. A START condition will be transmitted when the bus becomes free. Switched to the not addressed slave mode; own SLA will be recognized; GCA will be recognized if SSGC = logic 1. A START condition will be transmitted when the bus becomes free. Switched to the not addressed slave mode; no recognition of own SLA or GCA. Switched to the not addressed slave mode; own SLA will be recognized; GCA will be recognized if SSGC = logic 1. Switched to the not addressed slave mode; no recognition of own SLA or GCA. A START condition will be transmitted when the bus becomes free. Switched to the not addressed slave mode; own SLA will be recognized; GCA will be recognized if SSGC = logic 1. A START condition will be transmitted when the bus becomes free. B8h No SSDAT action No SSDAT action 0 0 0 0 0 0 0 1 C0h Data Byte in SSDAT has been transmitted; NOT ACK has been received No SSDAT action 1 0 0 0 No SSDAT action 1 0 0 1 No SSDAT action Last data Byte in SSDAT has been transmitted (SSAA= 0); ACK has been received No SSDAT action 0 0 0 0 0 0 0 1 C8h No SSDAT action 1 0 0 0 No SSDAT action 1 0 0 1 Table 21-7. Status Code SSSTA Status for Miscellaneous States Application Software Response To SSCON Status of the TWI Bus and TWI Hardware To/From SSDAT No relevant state information available; SSI = 0 SSSTA SSSTO SSI SSAA Next Action Taken by TWI Hardware F8h No SSDAT action No SSCON action Wait or proceed current transfer. 00h Bus error due to an illegal START or STOP No SSDAT action condition 0 1 0 X Only the internal hardware is affected, no STOP condition is sent on the bus. In all cases, the bus is released and SSSTO is reset. 194 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B 21.2 Registers Table 21-8. 7 SDA Bit Number 7 AUXCON Register AUXCON (S:90h) – Auxiliary Control Register 6 SCL 5 4 AUDCDOUT 3 AUDCDIN 2 AUDCCLK 1 AUDCCS 0 KIN0 Bit Mnemonic SDA Description TWI Serial Data SDA is the bidirectional Two Wire data line. TWI Serial Clock When TWI controller is in master mode, SCL outputs the serial clock to the slave peripherals. When TWI controller is in slave mode, SCL receives clock from the master controller. Audio DAC Control Refer to Audio DAC interface section 6 SCL 5:1 0 KIN0 Keyboard Input Line Reset Value = 1111 1111b 195 4341F–MP3–03/06 Table 21-9. 7 SSCR2 SSCON Register SSCON (S:93h) – Synchronous Serial Control Register 6 SSPE Bit Mnemonic SSCR2 5 SSSTA 4 SSSTO 3 SSI 2 SSAA 1 SSCR1 0 SSCR0 Bit Number 7 Description Synchronous Serial Control Rate Bit 2 R efer to Table 21-1 for rate description. Synchronous Serial Peripheral Enable Bit Set to enable the controller. C lear to disable the controller. Synchronous Serial Start Flag Set to send a START condition on the bus. C lear not to send a START condition on the bus. Synchronous Serial Stop Flag Set to send a STOP condition on the bus. C lear not to send a STOP condition on the bus. Synchronous Serial Interrupt Flag Set by hardware when a serial interrupt is requested. Must be cleared by software to acknowledge interrupt. Synchronous Serial Assert Acknowledge Flag Set to enable slave modes. Slave modes are entered when SLA or GCA (if SSGC set) is recognized. C lear to disable slave modes. Master Receiver Mode in progress C lear to force a not acknowledge (high level on SDA). Set to force an acknowledge (low level on SDA). Master Transmitter Mode in progress This bit has no specific effect when in master transmitter mode. Slave Receiver Mode in progress C lear to force a not acknowledge (high level on SDA). Set to force an acknowledge (low level on SDA). Slave Transmitter Mode in progress C lear to isolate slave from the bus after last data Byte transmission. Set to enable slave mode. Synchronous Serial Control Rate Bit 1 R efer to Table 21-1 for rate description. Synchronous Serial Control Rate Bit 0 R efer to Table 21-1 for rate description. 6 SSPE 5 SSSTA 4 SSSTO 3 SSI 2 SSAA 1 SSCR1 0 SSCR0 Reset Value = 0000 0000b 196 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B Table 21-10. SSSTA Register SSSTA (S:94h) – Synchronous Serial Status Register 7 SSC4 6 SSC3 Bit Mnemonic SSC4:0 0 5 SSC2 4 SSC1 3 SSC0 2 0 1 0 0 0 Bit Number 7:3 2:0 Description Synchronous Serial Status Code Bits 0 to 4 R efer to Table 21-2 to Table 21-6 for status description. Always 0. Reset Value = F8h Table 21-11. SSDAT Register SSDAT (S:95h) – Synchronous Serial Data Register 7 SSD7 6 SSD6 Bit Mnemonic SSD7:1 SSD0 5 SSD5 4 SSD4 3 SSD3 2 SSD2 1 SSD1 0 SSD0 Bit Number 7:1 0 Description Synchronous Serial Address bits 7 to 1 or Synchronous Serial Data Bits 7 to 1 Synchronous Serial Address bit 0 (R/W) or Synchronous Serial Data Bit 0 Reset Value = 1111 1111b Table 21-12. SSADR Register SSADR (S:96h) – Synchronous Serial Address Register 7 SSA7 6 SSA6 Bit Mnemonic SSA7:1 5 SSA5 4 SSA4 3 SSA3 2 SSA2 1 SSA1 0 SSGC Bit Number 7:1 Description Synchronous Serial Slave Address Bits 7 to 1 Synchronous Serial General Call Bit Set to enable the general call address recognition. C lear to disable the general call address recognition. 0 SSGC Reset Value = 1111 1110b 197 4341F–MP3–03/06 198 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B 22. Analog to Digital Converter The AT8XSND2CMP3B implement a 2-channel 10-bit (8 true bits) analog to digital converter (ADC). First channel of this ADC can be used for battery monitoring while the second one can be used for voice sampling at 8 kHz. The AT8xC51SND2C does not include the A/D converter. 22.1 Description The A/D converter interfaces with the C51 core through four special function registers: ADCON, the ADC control register (see Table 3); ADDH and ADDL, the ADC data registers (see Table 5 and Table 6); and ADCLK, the ADC clock register (see Table 4). As shown in Figure 22-1, the ADC is composed of a 10-bit cascaded potentiometric digital to analog converter, connected to the negative input of a comparator. The output voltage of this DAC is compared to the analog voltage stored in the Sample and Hold and coming from AIN0 or AIN1 input depending on the channel selected (see T able 2). The 10-bit ADDAT converted value (see formula in Figure 22-1) is delivered in ADDH and ADDL registers, ADDH is giving the 8 most significant bits while ADDL is giving the 2 least significant bits. Figure 22-1. ADC Structure ADCON.5 ADCON.3 ADEN ADSST ADCON.4 ADC CLOCK ADEOC CONTROL ADC Interrupt Request EADC IEN1.3 AIN1 AIN0 0 + 1 AVSS 8 ADDH ADDL SAR Sample and Hold R/2R DAC 2 ADCS ADCON.0 10 Figure 22-2 shows the timing diagram of a complete conversion. For simplicity, the figure depicts the waveforms in idealized form and do not provide precise timing information. For ADC characteristics and timing parameters refer to the section “AC Characteristics”. 4341F–MP3–03/06 F E RV -- - -- -- - - ---N-I-V-----3-2-0-1 ⋅ = TADDA AREFP AREFN 199 Figure 22-2. Timing Diagram CLK TADCLK ADEN TSETUP ADSST TCONV ADEOC 22.1.1 Clock Generator The ADC clock is generated by division of the peripheral clock (see details in section “X2 Feature”, page 14). The division factor is then given by ADCP4:0 bits in ADCLK register. Figure 223 shows the ADC clock generator and its calculation formula(1). Figure 22-3. ADC Clock Generator and Symbol Caution: ADCLK PER CLOCK ÷2 ADC CLOCK ADCD4:0 ADC Clock PERclk ADCclk = ------------------------2 ⋅ ADCD Note: ADC Clock Symbol 1. In all cases, the ADC clock frequency may be higher than the maximum FADCLK parameter reported in the section “Analog to Digital Converter”, page 202. 2. The ADCD value of 0 is equivalent to an ADCD value of 32. 22.1.2 Channel Selection The channel on which conversion is performed is selected by the ADCS bit in ADCON register according to Table 2. Table 2. ADC Channel Selection ADCS 0 1 Channel AIN1 AIN0 22.1.3 Conversion Precision The 10-bit precision conversion is achieved by stopping the CPU core activity during conversion for limiting the digital noise induced by the core. This mode called the Pseudo-Idle mode(1),(2) is enabled by setting the ADIDL bit in ADCON register(3). Thus, when conversion is launched (see Section "Conversion Launching", page 201), the CPU core is stopped until the end of the con- 200 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B version (see Section "End Of Conversion", page 201). This bit is cleared by hardware at the end of the conversion. Notes: 1. Only the CPU activity is frozen, peripherals are not affected by the Pseudo-Idle mode. 2. If some interrupts occur during the Pseudo-Idle mode, they will be delayed and processed, according to their priority after the end of the conversion. 3. Concurrently with ADSST bit. 22.1.4 Configuration The ADC configuration consists in programming the ADC clock as detailed in the Section "Clock Generator", page 200. The ADC is enabled using the ADEN bit in ADCON register. As shown in Figure 93, user must wait the setup time (TSETUP) before launching any conversion. Figure 22-4. ADC Configuration Flow ADC Configuration Program ADC Clock ADCD4:0 = xxxxxb Enable ADC ADIDL = x ADEN = 1 Wait Setup Time 22.1.5 Conversion Launching The conversion is launched by setting the ADSST bit in ADCON register, this bit remains set during the conversion. As soon as the conversion is started, it takes 11 clock periods (TCONV) before the data is available in ADDH and ADDL registers. Figure 22-5. ADC Conversion Launching Flow ADC Conversion Start Select Channel ADCS = 0-1 Start Conversion ADSST = 1 22.1.6 End Of Conversion The end of conversion is signalled by the ADEOC flag in ADCON register becoming set or by the ADSST bit in ADCON register becoming cleared. ADEOC flag can generate an interrupt if 201 4341F–MP3–03/06 enabled by setting EADC bit in IEN1 register. This flag is set by hardware and must be reset by software. 22.2 Registers Table 3. ADCON Register ADCON (S:F3h) – ADC Control Register 7 6 ADIDL Bit Mnemonic 5 ADEN 4 ADEOC 3 ADSST 2 1 0 ADCS Bit Number 7 Description Reserved The value read from this bit is always 0. Do not set this bit. ADC Pseudo-Idle Mode Set to suspend the CPU core activity (pseudo-idle mode) during conversion. C lear by hardware at the end of conversion. ADC Enable Bit Set to enable the A to D converter. C lear to disable the A to D converter and put it in low power stand by mode. End Of Conversion Flag Set by hardware when ADC result is ready to be read. This flag can generate an interrupt. Must be cleared by software. Start and Status Bit Set to start an A to D conversion on the selected channel. C leared by hardware at the end of conversion. Reserved The value read from these bits is always 0. Do not set these bits. Channel Selection Bit Set to select channel 0 for conversion. C lear to select channel 1 for conversion. 6 ADIDL 5 ADEN 4 ADEOC 3 ADSST 2-1 - 0 ADCS Reset Value = 0000 0000b Table 4. ADCLK Register ADCLK (S:F2h) – ADC Clock Divider Register 7 6 Bit Mnemonic 5 4 ADCD4 3 ADCD3 2 ADCD2 1 ADCD1 0 ADCD0 Bit Number 7-5 Description Reserved The value read from these bits is always 0. Do not set these bits. ADC Clock Divider 5-bit divider for ADC clock generation. 4-0 ADCD4:0 Reset Value = 0000 0000b 202 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B Table 5. ADDH Register ADDH (S:F5h Read Only) – ADC Data High Byte Register 7 ADAT9 6 ADAT8 Bit Mnemonic ADAT9:2 5 ADAT7 4 ADAT6 3 ADAT5 2 ADAT4 1 ADAT3 0 ADAT2 Bit Number 7-0 Description ADC Data 8 Most Significant Bits of the 10-bit ADC data. Reset Value = 0000 0000b Table 6. ADDL Register ADDL (S:F4h Read Only) – ADC Data Low Byte Register 7 6 Bit Mnemonic 5 4 3 2 1 ADAT1 0 ADAT0 Bit Number 7-2 Description Reserved The value read from these bits is always 0. Do not set these bits. ADC Data 2 Least Significant Bits of the 10-bit ADC data. 1-0 ADAT1:0 Reset Value = 0000 0000b 203 4341F–MP3–03/06 23. Keyboard Interface The AT8xC51SND2C implement a keyboard interface allowing the connection of a keypad. It is based on one input with programmable interrupt capability on both high or low level. This input allows exit from idle and power down modes. 23.1 Description The keyboard interfaces with the C51 core through 2 special function registers: KBCON, the keyboard control register (see Table 23-2); and KBSTA, the keyboard control and status register (see Table 23-3). An interrupt enable bit (EKB in IEN1 register) allows global enable or disable of the keyboard interrupt (see Figure 23-1). As detailed in Figure 23-2 this keyboard input has the capability to detect a programmable level according to KINL0 bit value in KBCON register. Level detection is then reported in interrupt flag KINF0 in KBSTA register. A keyboard interrupt is requested each time this flag is set. This flag can be masked by software using KINM0 bits in KBCON register and is cleared by reading KBSTA register. Figure 23-1. Keyboard Interface Block Diagram KIN0 Input Circuitry EKB IEN1.4 Keyboard Interface Interrupt Request Figure 23-2. Keyboard Input Circuitry 0 KIN0 1 KINF0 KBSTA.0 KINM0 KINL0 KBCON.4 KBCON.0 23.1.1 Power Reduction Mode KIN0 inputs allow exit from idle and power-down modes as detailed in section “Power Management”, page 47. To enable this feature, KPDE bit in KBSTA register must be set to logic 1. Due to the asynchronous keypad detection in power down mode (all clocks are stopped), exit may happen on parasitic key press. In this case, no key is detected and software must enter power down again. 204 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B 23.2 Registers Table 23-1. 7 SDA Bit Number 7:6 AUXCON Register AUXCON (S:90h) – Auxiliary Control Register 6 SCL 5 4 AUDCDOUT 3 AUDCDIN 2 AUDCCLK 1 AUDCCS 0 KIN0 Bit Mnemonic Description TWI Lines Refer to TWI section. 5:1 0 KIN0 Audio DAC Control Refer to Audio DAC section. Keyboard Input Interrupt. Reset Value = 1111 1111b Table 23-2. KBCON Register KBCON (S:A3h) – Keyboard Control Register 7 6 Bit Mnemonic 5 4 KINL0 3 2 1 0 KINM0 Bit Number 7-5 Description Reserved D o not set these bits. Keyboard Input Level Bit Set to enable a high level detection on the respective KIN0 input. C lear to enable a low level detection on the respective KIN0 input. Reserved D o not reset these bits. Keyboard Input Mask Bit Set to prevent the KINF0 flag from generating a keyboard interrupt. C lear to allow the KINF0 flag to generate a keyboard interrupt. 4 KINL0 3-1 - 0 KINM0 Reset Value = 0000 1111b 205 4341F–MP3–03/06 Table 23-3. KBSTA Register KBSTA (S:A4h) – Keyboard Control and Status Register 7 KPDE 6 Bit Mnemonic 5 4 3 2 1 0 KINF0 Bit Number Description Keyboard Power Down Enable Bit Set to enable exit of power down mode by the keyboard interrupt. C lear to disable exit of power down mode by the keyboard interrupt. Reserved The value read from these bits is always 0. Do not set these bits. Keyboard Input Interrupt Flag Set by hardware when the KIN0 input detects a programmed level. C leared when reading KBSTA. 7 KPDE 6-1 - 0 KINF0 Reset Value = 0000 0000b 206 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B 24. Electrical Characteristics 24.1 Absolute Maximum Rating *NOTICE: .................................... -0.3 Storage Temperature ......................................... -65 to +150 °C Voltage on any other Pin to V SS to +4.0 V IOL per I/O Pin ................................................................. 5 mA Power Dissipation ............................................................. 1 W Operating Conditions Ambient Temperature Under Bias........................ -40 to +85 °C VDD ......................................................................................................... 2.7 to 3.3V Stressing the device beyond the “Absolute Maximum Ratings” may cause permanent damage. These are stress ratings only. Operation beyond the “operating conditions” is not recommended and extended exposure beyond the “Operating Conditions” may affect device reliability. 24.2 24.2.1 DC Characteristics Digital Logic Digital DC Characteristics VDD = 2.7 to 3.3 V, TA = -40 to +85°C Parameter Input Low Voltage Input High Voltage (except RST, X1) Input High Voltage (RST, X1) Output Low Voltage (except P0, ALE, MCMD, MDAT, MCLK, SCLK, DCLK, DSEL, DOUT) Output Low Voltage (P0, ALE, MCMD, MDAT, MCLK, SCLK, DCLK, DSEL, DOUT) Output High Voltage (P1, P2, P3, P4 and P5) Output High Voltage (P0, P2 address mode, ALE, MCMD, MDAT, MCLK, SCLK, DCLK, DSEL, DOUT, D+, D-) Logical 0 Input Current (P1, P2, P3, P4 and P5) Input Leakage Current (P0, ALE, MCMD, MDAT, MCLK, SCLK, DCLK, DSEL, DOUT) Logical 1 to 0 Transition Current (P1, P2, P3, P4 and P5) Pull-Down Resistor Pin Capacitance VDD Data Retention Limit 50 90 10 1.8 VDD - 0.7 Min -0.5 0.2·VDD + 1.1 0.7·VDD Typ(1) Max 0.2·VDD - 0.1 VDD VDD + 0.5 0.45 Units V V V Test Conditions Table 24-1. Symbol VIL VIH1(2) VIH2 VOL1 V IOL = 1.6 mA VOL2 0.45 V IOL = 3.2 mA VOH1 V IOH= -30 μA VOH2 VDD - 0.7 V IOH= -3.2 mA IIL -50 μA VIN = 0.45 V ILI 10 μA 0.45< VIN< VDD ITL RRST CIO VRET -650 200 μA kΩ pF V VIN = 2.0 V TA= 25°C 207 4341F–MP3–03/06 Table 24-1. Symbol Digital DC Characteristics VDD = 2.7 to 3.3 V, TA = -40 to +85°C Parameter Min Typ(1) Max X1 / X2 mode 7/ 11.5 9/ 14.5 10.5 / 18 X1 / X2 mode 7/ 11.5 9/ 14.5 10.5 / 18 X1 / X2 mode 6.3 / 9.1 7.4 / 11.3 8.5 / 14 X1 / X2 mode 6.3 / 9.1 7.4 / 11.3 8.5 / 14 20 500 Units Test Conditions VDD < 3.3 V mA 12 MHz 16 MHz 20 MHz VDD < 3.3 V mA 12 MHz 16 MHz 20 MHz VDD < 3.3 V mA 12 MHz 16 MHz 20 MHz VDD < 3.3 V mA 12 MHz 16 MHz 20 MHz VRET < VDD < 3.3 V VRET < VDD < 3.3 V VDD < 3.3 V AT89C51SND2C Operating Current IDD AT83SND2C Operating Current (3) AT89C51SND2C Idle Mode Current IDL AT83SND2C Idle Mode Current (3) AT89C51SND2C Power-Down Mode Current IPD AT83SND2C Power-Down Mode Current IFP AT89C51SND2C Flash Programming Current μA μA mA 20 500 +15 Notes: 1. Typical values are obtained using VDD= 3 V and TA= 25°C. They are not tested and there is no guarantee on these values. 2. Flash retention is guaranteed with the same formula for VDD m in down to 0V. 3. See Table 24-2 for typical consumption in player mode. Table 24-2. Player Mode Typical Reference Design AT89C51SND2C Power Consumption IDD Test Conditions AT89C51SND2C at 16 MHz, X2 mode, VDD= 3 V No song playing. This consumption does not include AUDVBAT current. AT89C51SND2C at 16 MHz, X2 mode, VDD= 3 V MP3 Song with Fs= 44.1 KHz, at any bit rates (Variable Bit Rate) This consumption does not include AUDVBAT current. Stop 10 mA Playing 37 mA 208 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B 24.2.1.1 IDD, IDL and IPD Test Conditions Figure 24-1. IDD Test Condition, Active Mode VDD VDD RST VDD PVDD UVDD AUDVDD IDD (NC) Clock Signal X2 X1 P0 VSS PVSS UVSS AUDVSS TST VDD VSS All other pins are unconnected Figure 24-2. IDL Test Condition, Idle Mode VDD RST VSS VDD PVDD UVDD AUDVDD IDL (NC) Clock Signal X2 X1 P0 VSS PVSS UVSS AUDVSS TST VDD VSS All other pins are unconnected Figure 24-3. IPD Test Condition, Power-Down Mode VDD RST VSS VDD PVDD UVDD AUDVDD P0 MCMD MDAT TST IPD VDD (NC) X2 X1 VSS PVSS UVSS AUDVSS VSS All other pins are unconnected 209 4341F–MP3–03/06 24.2.2 24.2.2.1 Oscillator & Crystal Schematic Figure 24-4. Crystal Connection X1 C1 Q C2 VSS X2 Note: For operation with most standard crystals, no external components are needed on X1 and X2. It may be necessary to add external capacitors on X1 and X2 to ground in special cases (max 10 pF). X1 and X2 may not be used to drive other circuits. 24.2.2.2 Parameters Table 24-3. Oscillator & Crystal Characteristics VDD = 2.7 to 3.3 V, TA = -40 to +85°C Symbol CX1 CX2 CL DL F RS CS Parameter Internal Capacitance (X1 - VSS) Internal Capacitance (X2 - VSS) Equivalent Load Capacitance (X1 - X2) Drive Level Crystal Frequency Crystal Series Resistance Crystal Shunt Capacitance Min Typ 10 10 5 50 20 40 6 Max Unit pF pF pF μW MHz Ω pF 24.2.3 24.2.3.1 Phase Lock Loop Schematic Figure 24-5. PLL Filter Connection FILT R C1 VSS VSS C2 24.2.3.2 Parameters Table 24-4. PLL Filter Characteristics 210 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B VDD = 2.7 to 3.3 V, TA = -40 to +85°C Symbol R C1 C2 Filter Resistor Filter Capacitance 1 Filter Capacitance 2 Parameter Min Typ 100 10 2.2 Max Unit Ω nF nF 24.2.4 24.2.4.1 USB Connection Schematic Figure 24-6. USB Connection VDD VBUS D+ DGND To Power Supply R FS RUSB RUSB D+ D- VSS 24.2.4.2 Parameters Table 24-5. USB Termination Characteristics VDD = 3 to 3.3 V, TA = -40 to +85°C Symbol R USB RFS Parameter USB Termination Resistor USB Full Speed Resistor Min Typ 27 1.5 Max Unit Ω KΩ 24.2.5 24.2.6 24.2.6.1 DAC and PA Electrical Specifications PA AUDVBAT = 3.6V, TA = 25°C unless otherwise noted. High power mode, 100nF capacitor connected between CBP and AUDVSS, 470nF input capacitors, Load = 8 ohms. Figure 24-7. PA Specification Symbol Parameter Conditions Min 3.2 Inputs shorted, no load Capacitance Typ 6 AUDVBA T/2 Max 5.5 8 2 Unit V mA μA V AUDVBA Supply Voltage T IDD IDDstby VCBP Quiescent Current Standby Current DC Reference 211 4341F–MP3–03/06 Symbol VOS ZIN ZLFP ZLLP CL PSRR Parameter Output differential offset Input impedance Output load Output load Capacitive load Power supply rejection ratio Output Frequency bandwidth full gain Conditions Min -20 12K 6 100 - Typ 0 20k 8 150 60 Max 20 30k 32 300 100 - Unit mV W W W pF dB Active state Full Power mode Low-Power mode 200 – 2kHz Differential output 1KHz reference frequency 3dB attenuation. 470nF input coupling capacitors Off to on mode. Voltage already settled. Input capacitors precharged - BW 50 - 20000 Hz tUP Output setup time - - 10 ms VN THDHP Output noise Output distortion Max gain, A weighted High power mode, VDD = 3.2V, 1KHz, Pout=100mW, gain=0dB Low power mode, VDD = 3.2V , 1KHz, Vout= 100mVpp, Max gain, load 8 ohms in serie with 200 ohms - 120 50 500 - µVRMS dB THDLP Output distortion - 1 - % GACC GSTEP Overall Gain accuracy Gain Step Accuracy -2 -0.7 0 0 2 0.7 dB dB Figure 24-8. Maximum Dissipated Power Versus Power Supply 600 550 Dissipated Power [mW] 500 450 400 350 300 250 200 3,2 3,4 3,6 3,8 4 Supply Voltage AUDVBAT [V] 4,2 8 Ohms load 6.5 Ohms load 212 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B Figure 24-9. Dissipated Power vs Output Power, AUDVBAT = 3.2V 600 550 500 Dissipated Power [mW] 450 400 350 300 250 200 150 100 50 0 0 100 200 300 400 500 600 700 800 Output Power [mW] 8 Ohms load 6.5 Ohms load 24.2.6.2 DAC AUDVDD, HSVDD = 2.8 V, Ta=25°C, typical case, unless otherwise noted All noise and distortion specifications are measured in the 20 Hz to 0.425xFs and A-weighted filtered. Full Scale levels scale proportionally with the analog supply voltage. Table 24-6. OVERALL Audio DAC Specification MIN -40 2.7 2.4 3.2 TYP +25 2.8 2.8 MAX +125 3.3 3.3 5.5 UNITS °C V V V Operating Temperature Analog Supply Voltage (AUDVDD, HSVDD) Digital Supply Voltage (VDD) Audio Amplifier Supply (AUDVBAT) DIGITAL INPUTS/OUTPUTS Resolution Logic Family Logic Coding ANALOG PERFORMANCE – DAC to Line-out/Headphone Output Output level for full scale input (for AUDVDD, HSVDD = 2.8 V) Output common mode voltage Output load resistance (on HSL, HSR) - Headphone load - Line load 20 CMOS 2’s Complement Bits 1.65 0.5xHSVDD Vpp V 16 32 10 Ohm kOhm 213 4341F–MP3–03/06 Table 24-6. OVERALL Audio DAC Specification (Continued) MIN TYP MAX UNITS Output load capacitance (on HSL, HSR) - Headphone load - Line load Signal to Noise Ratio (–1dBFS @ 1kHz input and 0dB Gain) - Line and Headphone loads Total Harmonic Distortion (–1dBFS @ 1kHz input and 0dB Gain) - Line Load - Headphone Load - Headphone Load (16 Ohm) 30 30 1000 150 pF pF 87 92 dB -80 -65 -40 -76 -60 dB dB dB Dynamic Range (measured with -60 dBFS @ 1kHz input, extrapolated to full-scale) - Line Load 88 - Headphone Load 70 Interchannel mismatch Left-channel to right-channel crosstalk (@ 1kHz) Output Power Level Control Range Output Power Level Control Step PSRR - 1kHz - 20kHz Maximum output slope at power up (100 to 220F coupling capacitor) ANALOG PERFORMANCE – Line-in/Microphone Input to Line-out/Headphone Output Input level for full scale output - 0dBFS Level @ AUDVDD, HSVDD = 2.8 V and 0 dB gain @ AUDVDD, HSVDD = 2.8 V and 20 dB gain Input common mode voltage Input impedance Signal to Noise Ratio -1 dBFS @ 1kHz input and 0 dB gain -21 dBFS @ 1kHz input and 20 dB gain Dynamic Range (extrapolated to full scale level) -60 dBFS @ 1kHz input and 0 dB gain -60 dBFS @ 1kHz input and 20 dB gain Total Harmonic Distortion –1dBFS @ 1kHz input and 0 dB gain –1dBFS @ 1kHz input and 20 dB gain Interchannel mismatch 7 -6 93 74 0.1 -90 3 1 -80 6 dB dB dB dB dB dB 55 50 3 dB dB V/s 1.65 583 0.165 58.3 0.5xAUDVDD 10 Vpp mVrms Vpp mVrms V kOhm 81 85 71 dB 82 86 72 dB -80 -75 0.1 -76 -68 1 dB dB 214 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B Table 24-6. OVERALL Left-channel to right-channel crosstalk (@ 1kHz) ANALOG PERFORMANCE – Differential mono input amplifier Differential input level for full scale output - 0dBFS Level @ AUDVDD, HSVDD = 2.8 V and 0 dB gain Input common mode voltage Input impedance Signal to Noise Ratio (-1 dBFS @ 1kHz input and 0 dB gain) Total Harmonic Distortion (–1dBFS @ 1kHz input and 0 dB gain) ANALOG PERFORMANCE – PA Driver Differential output level for full scale input (for AUDVDD, HSVDD = 3 V) Output common mode voltage Output load Signal to Noise Ratio (–1dBFS @ 1kHz input and 0dB Gain) Total Harmonic Distortion (–1dBFS @ 1kHz input and 0dB Gain) MASTER CLOCK Master clock Maximum Long Term Jitter DIGITAL FILTER PERFORMANCE Frequency response (10 Hz to 20 kHz) Deviation from linear phase (10 Hz to 20 kHz) Passband 0.1 dB corner Stopband Stopband Attenuation DE-EMPHASIS FILTER PERFORMANCE (for 44.1kHz Fs) Frequency Pass band Transition band Stop Band Power Performance Current consumption from Audio Analog supply AVDD, HSVDD in power on Current consumption from Audio Analog supply AVDD, HSVDD in power down Power on Settling Time - From full Power Down to Full Power Up (AUDVREF and AUDVCM decoupling capacitors charge) - Linein amplifier (Line-in coupling capacitors charge) - Driver amplifier (out driver DC blocking capacitors charge) 9.5 10 mA μA Audio DAC Specification (Continued) MIN TYP -90 MAX -80 UNITS dB 1.65 583 0.5xAUDVDD 7 76 10 80 -85 -81 Vppdif mVrms V kOhm dB dB 3.3 0.5xHSVDD 10 76 80 -75 -71 Vppdif V kOhm pF dB dB 30 1.5 nspp +/- 0.1 +/- 0.1 0.4535 0.5465 65 dB deg Fs Fs dB Gain -1dB Logarithm decay -10.45dB Margin 1dB 1dB 1dB 0Hz to 3180Hz 3180Hz to 10600Hz 10600Hz to 20kHz 500 50 500 ms ms ms 215 4341F–MP3–03/06 24.2.7 Digital Filters Transfer Function Figure 24-10. Channel Filter Figure 24-11. De-emphasis Filter 0 -2 -4 Gain (dB) -6 -8 -10 -12 10 3 10 4 Frequency (Hz) 216 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B 24.2.7.1 Audio DAC and PA Connection Figure 24-12. DAC and PA Connection PAINN Audio Dac and PA Connection VDD C17 VSS 3V from LDO Battery 3.2V to 5.5V AUDVSS C16 AUDVBAT CBP AUDVSS C7 HPP AUDVDD 3V from LDO AUDVSS 8 Ohm Loud Speaker HPN LPHN C15 R1 PAINP AUDVREF HSVDD C18 AUDVSS C19 HSVSS C9 MONOP VSS MONON R C12 C8 LINER C3 LINEL AUDVCM C11 AUDVSS Stereo Line Input L Mono AUDVSS mono input (+) AUXP Differential Input mono input C1 (-) C6 C4 AUXN 32 Ohm 32 Ohm Headset or Line Out 32 Ohm C5 HSR HSL INGND AUDVSS AUDVSS ESDVSS C10 ESDVSS VSS VSS 217 4341F–MP3–03/06 Table 24-7. Symbol C1 C3 C4 C5 C6 C7 C8 C9 C10 C11 C12 C15 C16 C17 C18 C19 R1 DAC and PA Characteristics Parameter Capacitance Capacitance Capacitance Capacitance Capacitance Capacitance Capacitance Capacitance Capacitance Capacitance Capacitance Capacitance Capacitance Capacitance Capacitance Capacitance Resistor Typ 470 470 470 100 100 100 470 100n 10 10 470 470 22 100 100 100 200 Unit nF nF nF μF μF nF nF μF μF μF nF nF μF nF nF nF Ω 24.2.8 24.2.8.1 In System Programming Schematic Figure 24-13. ISP Pull-Down Connection ISP RISP VSS 24.2.8.2 Parameters Table 24-8. ISP Pull-Down Characteristics VDD = 2.7 to 3.3 V, TA = -40 to +85°C Symbol RISP Parameter ISP Pull-Down Resistor Min Typ 2.2 Max Unit KΩ 218 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B 24.3 24.3.1 24.3.1.1 AC Characteristics External Program Bus Cycles Definition of Symbols Table 24-9. External Program Bus Cycles Timing Symbol Definitions Signals Conditions H L V X Z High Low Valid No Longer Valid Floating A I L P Address Instruction In ALE PSEN 24.3.1.2 Timings Test conditions: capacitive load on all pins= 50 pF. Table 24-10. External Program Bus Cycle - Read AC Timings VDD = 2.7 to 3.3 V, TA = -40 to +85°C Variable Clock Standard Mode Symbol TCLCL TLHLL TAVLL TLLAX TLLIV TPLPH TPLIV TPXIX TPXIZ TAVIV TPLAZ Clock Period ALE Pulse Width Address Valid to ALE Low Address hold after ALE Low ALE Low to Valid Instruction PSEN Pulse Width PSEN Low to Valid Instruction Instruction Hold After PSEN High Instruction Float After PSEN High Address Valid to Valid Instruction PSEN Low to Address Float 0 TCLCL-10 5·TCLCL-35 10 Variable Clock X2 Mode Min 50 TCLCL-15 0.5·TCLCL-20 0.5·TCLCL-20 2·TCLCL-35 1.5·TCLCL-25 Parameter Min 50 2·TCLCL -15 TCLCL-20 TCLCL-20 4·TCLCL -35 3·TCLCL -25 Max Max Unit ns ns ns ns ns ns 3·TCLCL-35 0 1.5·TCLCL-35 ns ns 0.5·TCLCL-10 2.5·TCLCL-35 10 ns ns ns 219 4341F–MP3–03/06 24.3.1.3 Waveforms Figure 24-14. External Program Bus Cycle - Read Waveforms ALE TLHLL TLLPL PSEN TPLIV TPLAZ TAVLL TLLAX P0 D7:0 A7:0 TPXAV TPXIZ TPXIX D7:0 Instruction In P2 A15:8 A7:0 D7:0 Instruction In A15:8 TPLPH 24.3.2 24.3.2.1 External Data 8-bit Bus Cycles Definition of Symbols Table 24-11. External Data 8-bit Bus Cycles Timing Symbol Definitions Signals A D L Q R W Address Data In ALE Data Out RD WR H L V X Z Conditions High Low Valid No Longer Valid Floating 24.3.2.2 Timings Test conditions: capacitive load on all pins= 50 pF. Table 24-12. External Data 8-bit Bus Cycle - Read AC Timings VDD = 2.7 to 3.3 V, TA = -40 to +85°C Variable Clock Standard Mode Symbol TCLCL TLHLL TAVLL TLLAX TLLRL Variable Clock X2 Mode Min 50 TCLCL -15 0.5·TCLCL-20 0.5·TCLCL-20 1.5·TCLCL-30 Parameter Clock Period ALE Pulse Width Address Valid to ALE Low Address hold after ALE Low ALE Low to RD Low Min 50 2·TCLCL -15 TCLCL-20 TCLCL-20 3·TCLCL -30 Max Max Unit ns ns ns ns ns 220 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B Variable Clock Standard Mode Symbol TRLRH TRHLH TAVDV TAVRL TRLDV TRLAZ TRHDX TRHDZ Variable Clock X2 Mode Min 3·TCLCL -25 Parameter RD Pulse Width RD high to ALE High Address Valid to Valid Data In Address Valid to RD Low RD Low to Valid Data RD Low to Address Float Data Hold After RD High Instruction Float After RD High Min 6·TCLCL -25 TCLCL-20 Max Max Unit ns TCLCL+20 9·TCLCL-65 0.5·TCLCL-20 0.5·TCLCL +20 4.5·TCLCL-65 ns ns ns 4·TCLCL -30 5·TCLCL-30 0 0 2·TCLCL-25 2·TCLCL -30 2.5·TCLCL-30 0 0 TCLCL-25 ns ns ns ns Table 24-13. External Data 8-bit Bus Cycle - Write AC Timings VDD = 2.7 to 3.3 V, TA = -40 to +85°C Variable Clock Standard Mode Symbol TCLCL TLHLL TAVLL TLLAX TLLWL TWLWH TWHLH TAVWL TQVWH TWHQX Variable Clock X2 Mode Min 50 TCLCL -15 0.5·TCLCL-20 0.5·TCLCL-20 1.5·TCLCL-30 3·TCLCL -25 Parameter Clock Period ALE Pulse Width Address Valid to ALE Low Address hold after ALE Low ALE Low to WR Low WR Pulse Width WR High to ALE High Address Valid to WR Low Data Valid to WR High Data Hold after WR High Min 50 2·TCLCL -15 TCLCL-20 TCLCL-20 3·TCLCL -30 6·TCLCL -25 TCLCL-20 4·TCLCL -30 7·TCLCL -20 TCLCL-15 Max Max Unit ns ns ns ns ns ns TCLCL+20 0.5·TCLCL-20 2·TCLCL -30 3.5·TCLCL-20 0.5·TCLCL-15 0.5·TCLCL +20 ns ns ns ns 221 4341F–MP3–03/06 24.3.2.3 Waveforms Figure 24-15. External Data 8-bit Bus Cycle - Read Waveforms ALE TLHLL TLLRL TRLRH TRHLH RD TRLDV TAVLL P0 TRLAZ TLLAX A7:0 TAVRL TAVDV P2 A15:8 D7:0 Data In TRHDZ TRHDX Figure 24-16. External Data 8-bit Bus Cycle - Write Waveforms ALE TLHLL TLLWL TWLWH TWHLH WR TAVWL TAVLL P0 TLLAX A7:0 TQVWH D7:0 Data Out P2 A15:8 TWHQX 24.3.3 24.3.3.1 External IDE 16-bit Bus Cycles Definition of Symbols Table 24-14. External IDE 16-bit Bus Cycles Timing Symbol Definitions Signals A D L Q R W Address Data In ALE Data Out RD WR H L V X Z Conditions High Low Valid No Longer Valid Floating 222 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B 24.3.3.2 Timings Test conditions: capacitive load on all pins= 50 pF. Table 24-15. External IDE 16-bit Bus Cycle - Data Read AC Timings VDD = 2.7 to 3.3 V, TA = -40 to +85°C Variable Clock Standard Mode Symbol TCLCL TLHLL TAVLL TLLAX TLLRL TRLRH TRHLH TAVDV TAVRL TRLDV TRLAZ TRHDX TRHDZ Variable Clock X2 Mode Min 50 TCLCL -15 0.5·TCLCL-20 0.5·TCLCL-20 1.5·TCLCL-30 3·TCLCL -25 Parameter Clock Period ALE Pulse Width Address Valid to ALE Low Address hold after ALE Low ALE Low to RD Low RD Pulse Width RD high to ALE High Address Valid to Valid Data In Address Valid to RD Low RD Low to Valid Data RD Low to Address Float Data Hold After RD High Instruction Float After RD High Min 50 2·TCLCL -15 TCLCL-20 TCLCL-20 3·TCLCL -30 6·TCLCL -25 TCLCL-20 Max Max Unit ns ns ns ns ns ns TCLCL+20 9·TCLCL-65 0.5·TCLCL-20 0.5·TCLCL +20 4.5·TCLCL-65 ns ns ns 4·TCLCL -30 5·TCLCL-30 0 0 2·TCLCL-25 2·TCLCL -30 2.5·TCLCL-30 0 0 TCLCL-25 ns ns ns ns Table 24-16. External IDE 16-bit Bus Cycle - Data Write AC Timings VDD = 2.7 to 3.3 V, TA = -40 to +85°C Variable Clock Standard Mode Symbol TCLCL TLHLL TAVLL TLLAX TLLWL TWLWH TWHLH TAVWL TQVWH TWHQX Variable Clock X2 Mode Min 50 TCLCL -15 0.5·TCLCL-20 0.5·TCLCL-20 1.5·TCLCL-30 3·TCLCL -25 Parameter Clock Period ALE Pulse Width Address Valid to ALE Low Address hold after ALE Low ALE Low to WR Low WR Pulse Width WR High to ALE High Address Valid to WR Low Data Valid to WR High Data Hold after WR High Min 50 2·TCLCL -15 TCLCL-20 TCLCL-20 3·TCLCL -30 6·TCLCL -25 TCLCL-20 4·TCLCL -30 7·TCLCL -20 TCLCL-15 Max Max Unit ns ns ns ns ns ns TCLCL+20 0.5·TCLCL-20 2·TCLCL -30 3.5·TCLCL-20 0.5·TCLCL-15 0.5·TCLCL +20 ns ns ns ns 223 4341F–MP3–03/06 24.3.3.3 Waveforms Figure 24-17. External IDE 16-bit Bus Cycle - Data Read Waveforms ALE TLHLL TLLRL TRLRH TRHLH RD TRLDV TAVLL P0 TRLAZ TLLAX A7:0 TAVRL TAVDV P2 A15:8 D15:8(1) Data In D7:0 Data In TRHDZ TRHDX Note: 1. D15:8 is written in DAT16H SFR. Figure 24-18. External IDE 16-bit Bus Cycle - Data Write Waveforms ALE TLHLL TLLWL TWLWH TWHLH WR TAVWL TAVLL P0 TLLAX A7:0 TQVWH D7:0 Data Out P2 A15:8 D15:8(1) Data Out TWHQX Note: 1. D15:8 is the content of DAT16H SFR. 24.4 24.4.0.4 SPI Interface Definition of Symbols Table 24-17. SPI Interface Timing Symbol Definitions Signals C I O Clock Data In Data Out H L V X Z Conditions High Low Valid No Longer Valid Floating 224 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B 24.4.0.5 Timings Test conditions: capacitive load on all pins= 50 pF. Table 24-18. SPI Interface Master AC Timing VDD = 2.7 to 3.3 V, TA = -40 to +85°C Symbol Parameter Slave Mode TCHCH TCHCX TCLCX TSLCH, TSLCL TIVCL, TIVCH TCLIX, TCHIX TCLOV, TCHOV TCLOX, TCHOX TCLSH, TCHSH TSLOV TSHOX TSHSL TILIH TIHIL TOLOH TOHOL Clock Period Clock High Time Clock Low Time SS Low to Clock edge Input Data Valid to Clock Edge Input Data Hold after Clock Edge Output Data Valid after Clock Edge Output Data Hold Time after Clock Edge SS High after Clock Edge SS Low to Output Data Valid Output Data Hold after SS High SS High to SS Low Input Rise Time Input Fall Time Output Rise time Output Fall Time (1) Min Max Unit 2 0.8 0.8 100 40 40 40 0 0 50 50 TPER TPER TPER ns ns ns ns ns ns ns ns 2 2 100 100 μs μs ns ns Master Mode TCHCH TCHCX TCLCX TIVCL, TIVCH TCLIX, TCHIX TCLOV, TCHOV TCLOX, TCHOX TILIH TIHIL TOLOH TOHOL Clock Period Clock High Time Clock Low Time Input Data Valid to Clock Edge Input Data Hold after Clock Edge Output Data Valid after Clock Edge Output Data Hold Time after Clock Edge Input Data Rise Time Input Data Fall Time Output Data Rise time Output Data Fall Time 0 2 2 50 50 2 0.8 0.8 20 20 40 TPER TPER TPER ns ns ns ns μs μs ns ns Note: 1. Value of this parameter depends on software. 225 4341F–MP3–03/06 24.4.0.6 Waveforms Figure 24-19. SPI Slave Waveforms (SSCPHA= 0) SS (input) TSLCH TSLCL SCK (SSCPOL= 0) (input) SCK (SSCPOL= 1) (input) TSLOV MISO (output) SLAVE MSB OUT TIVCH TCHIX TIVCL TCLIX MOSI (input) MSB IN BIT 6 LSB IN TCLOV TCHOV BIT 6 TCHCH TCLCH TCLSH TCHSH TSHSL TCHCX TCLCX TCHCL TCLOX TCHOX SLAVE LSB OUT (1) TSHOX Note: 1. Not Defined but generally the MSB of the character which has just been received. Figure 24-20. SPI Slave Waveforms (SSCPHA= 1) SS (input) TSLCH TSLCL SCK (SSCPOL= 0) (input) SCK (SSCPOL= 1) (input) TSLOV MISO (output) (1) TCHCH TCLCH TCLSH TCHSH TSHSL TCHCX TCLCX TCHCL TCHOV TCLOV BIT 6 TCHOX TCLOX SLAVE LSB OUT TSHOX SLAVE MSB OUT TIVCH TCHIX TIVCL TCLIX MOSI (input) MSB IN BIT 6 LSB IN Note: 1. Not Defined but generally the LSB of the character which has just been received. 226 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B Figure 24-21. SPI Master Waveforms (SSCPHA= 0) SS (output) TCHCH SCK (SSCPOL= 0) (output) SCK (SSCPOL= 1) (output) TCLCH TCHCX TCLCX TCHCL TIVCH TCHIX TIVCL TCLIX MSB IN BIT 6 TCLOV TCHOV LSB IN TCLOX TCHOX LSB OUT Port Data MOSI (input) MISO (output) Port Data MSB OUT BIT 6 Note: 1. SS handled by software using general purpose port pin. Figure 24-22. SPI Master Waveforms (SSCPHA= 1) SS(1) (output) TCHCH SCK (SSCPOL= 0) (output) SCK (SSCPOL= 1) (output) TCLCH TCHCX TCLCX TCHCL TIVCH TCHIX TIVCL TCLIX MSB IN TCLOV BIT 6 TCLOX TCHOX BIT 6 LSB OUT Port Data LSB IN MOSI (input) MISO (output) TCHOV Port Data MSB OUT Note: 1. SS handled by software using general purpose port pin. 227 4341F–MP3–03/06 24.4.1 24.4.1.1 Two-wire Interface Timings Table 24-19. TWI Interface AC Timing VDD = 2.7 to 3.3 V, TA = -40 to +85°C INPUT Min Max 14·TCLCL(4) 16·TCLCL(4) 14·TCLCL(4) 1 μs 0.3 μs 250 ns 250 ns 250 ns 0 ns 14·TCLCL(4) 14·TCLCL(4) 14·TCLCL(4) 1 μs 0.3 μs Symbol THD; STA TLOW THIGH TRC TFC TSU; DAT1 TSU; DAT2 TSU; DAT3 THD; DAT TSU; STA TSU; STO TBUF TRD TFD Parameter Start condition hold time SCL low time SCL high time SCL rise time SCL fall time Data set-up time SDA set-up time (before repeated START condition) SDA set-up time (before STOP condition) Data hold time Repeated START set-up time STOP condition set-up time Bus free time SDA rise time SDA fall time OUTPUT Min Max 4.0 μs(1) 4.7 μs(1) 4.0 μs(1) -(2) 0.3 μs(3) 20·TCLCL(4)- TRD 1 μs(1) 8·TCLCL(4) 8·TCLCL(4) - TFC 4.7 μs(1) 4.0 μs(1) 4.7 μs(1) -(2) 0.3 μs(3) Notes: 1. At 100 kbit/s. At other bit-rates this value is inversely proportional to the bit-rate of 100 kbit/s. 2. Determined by the external bus-line capacitance and the external bus-line pull-up resistor, this must be < 1 μs. 3. Spikes on the SDA and SCL lines with a duration of less than 3·TCLCL will be filtered out. Maximum capacitance on bus-lines SDA and SCL= 400 pF. 4. TCLCL= TOSC= one oscillator clock period. 228 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B 24.4.1.2 Waveforms Figure 24-23. Two Wire Waveforms Repeated START condition START condition STOP condition START or Repeated START condition Trd SDA (INPUT/OUTPUT) Tfd Trc SCL (INPUT/OUTPUT) Tfc Tsu ;STA 0.7 VDD 0.3 VDD Tsu;STO Tbuf Tsu;DAT3 0.7 VDD 0.3 VDD 2 Thd;STA Tlow Thigh Tsu;DAT1 Thd;DAT Tsu;DAT 24.4.2 24.4.2.1 MMC Interface Definition of symbols Table 24-20. MMC Interface Timing Symbol Definitions Signals C D O Clock Data In Data Out H L V X Conditions High Low Valid No Longer Valid 24.4.2.2 Timings Table 24-21. MMC Interface AC timings VDD = 2.7 to 3.3 V, TA = -40 to +85°C, CL ≤ 100pF (10 cards) Symbol TCHCH TCHCX TCLCX TCLCH TCHCL TDVCH TCHDX TCHOX TOVCH Clock Period Clock High Time Clock Low Time Clock Rise Time Clock Fall Time Input Data Valid to Clock High Input Data Hold after Clock High Output Data Hold after Clock High Output Data Valid to Clock High 3 3 5 5 Parameter Min 50 10 10 10 10 Max Unit ns ns ns ns ns ns ns ns ns 229 4341F–MP3–03/06 24.4.2.3 Waveforms Figure 24-24. MMC Input-Output Waveforms TCHCH TCHCX MCLK TCHCL TCHIX MCMD Input MDAT Input TCHOX MCMD Output MDAT Output TOVCH TCLCH TIVCH TCLCX 24.4.3 24.4.3.1 Audio Interface Definition of symbols Table 24-22. Audio Interface Timing Symbol Definitions Signals C O S Clock Data Out Data Select H L V X Conditions High Low Valid No Longer Valid 24.4.3.2 Timings Table 24-23. Audio Interface AC timings VDD = 2.7 to 3.3 V, TA = -40 to +85°C, CL≤ 30pF Symbol TCHCH TCHCX TCLCX TCLCH TCHCL TCLSV TCLOV Parameter Clock Period Clock High Time Clock Low Time Clock Rise Time Clock Fall Time Clock Low to Select Valid Clock Low to Data Valid 30 30 10 10 10 10 Min Max 325.5(1) Unit ns ns ns ns ns ns ns Note: 1. 32-bit format with Fs= 48 KHz. 230 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B 24.4.3.3 Waveforms Figure 24-25. Audio Interface Waveforms TCHCH TCHCX DCLK TCHCL TCLSV DSEL TCLOV DDAT Right Left TCLCH TCLCX 24.4.4 24.4.4.1 Flash Memory Definition of symbols Table 24-24. Flash Memory Timing Symbol Definitions Signals S R B ISP RST FBUSY flag L V X Conditions Low Valid No Longer Valid 24.4.4.2 Timings Table 24-25. Flash Memory AC Timing VDD = 2.7 to 3.3 V, TA = -40 to +85°C Symbol TSVRL TRLSX TBHBL NFCY TFDR Parameter Input ISP Valid to RST Edge Input ISP Hold after RST Edge FLASH Internal Busy (Programming) Time Number of Flash Write Cycles Flash Data Retention Time 100K 10 Min 50 50 10 Typ Max Unit ns ns ms Cycle Years 231 4341F–MP3–03/06 24.4.4.3 Waveforms Figure 24-26. FLASH Memory - ISP Waveforms RST TSVRL ISP (1) TRLSX Note: 1. ISP must be driven through a pull-down resistor (see Section “In System Programming”, page 218). Figure 24-27. FLASH Memory - Internal Busy Waveforms FBUSY bit TBHBL 24.4.5 24.4.5.1 External Clock Drive and Logic Level References Definition of symbols Table 24-26. External Clock Timing Symbol Definitions Signals C Clock H L X Conditions High Low No Longer Valid 24.4.5.2 Timings Table 24-27. External Clock AC Timings VDD = 2.7 to 3.3 V, TA = -40 to +85°C Symbol TCLCL TCHCX TCLCX TCLCH TCHCL TCR Clock Period High Time Low Time Rise Time Fall Time Cyclic Ratio in X2 mode Parameter Min 50 10 10 3 3 40 60 Max Unit ns ns ns ns ns % 232 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B 24.4.5.3 Waveforms Figure 24-28. External Clock Waveform TCLCH VDD - 0.5 0.45 V VIH1 TCLCX TCHCL TCLCL TCHCX VIL Figure 24-29. AC Testing Input/Output Waveforms INPUTS VDD - 0.5 0.45 V 0.7 VDD 0.3 VDD OUTPUTS VIH min VIL max Note: 1. During AC testing, all inputs are driven at VDD -0.5 V for a logic 1 and 0.45 V for a logic 0. 2. Timing measurements are made on all outputs at VIH min for a logic 1 and VIL max for a logic 0. Figure 24-30. Float Waveforms VLOAD VLOAD + 0.1 V VLOAD - 0.1 V Timing Reference Points VOH - 0.1 V VOL + 0.1 V Note: For timing purposes, a port pin is no longer floating when a 100 mV change from load voltage occurs and begins to float when a 100 mV change from the loading VOH/V OL level occurs with IOL/IOH= ±20 mA. 233 4341F–MP3–03/06 25. Ordering Information Memory Size 64K Flash 64K Flash 64K Flash 64K Flash 64K ROM 64K ROM 64K Flash 64K ROM Supply Voltage 3V 3V 3V 3V 3V 3V 3V 3V 3V Temperature Range Industrial Industrial RoHS RoHS RoHS RoHS Green Green Green Max Frequency 40 MHz 40 MHz 40 MHz 40 MHz 40 MHz 40 MHz 40 MHz 40 MHz 40 MHz RoHS Compliant No No Yes Yes Yes Yes Yes Yes Yes Part Number AT89C51SND2C7FTIL AT89C51SND2C7FRIL AT89C51SND2C7FTJL AT89C51SND2C7FRJL AT83SND2Cxxx7FTJL AT83SND2Cxxx7FRJL AT89SND2CMP3B7FTUL AT83SND2CxxxB7FTUL AT80SND2CMP3B7FTUL ADC No No No No No No Yes Yes Yes Package BGA100 BGA100 BGA100 BGA100 BGA100 BGA100 BGA100 BGA100 BGA100 Packing Tray Reel Tray Reel Tray Reel Tray Tray Tray Product Marking 89C51SND2C-IL 89C51SND2C-JL 89C51SND2C-JL 89C51SND2C-JL 83C51SND2C-JL 83C51SND2C-JL 89SND2CMP3BUL 83SND2CxxxB-UL 80SND2CMP3BUL 234 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B 26. Package Information 26.1 CTBGA100 235 4341F–MP3–03/06 27. Datasheet Revision History 27.1 Changes from 4341A - 10/04 to 4341B - 01/05 1. Update Power Amplifier DC characteristics, Section “Electrical Characteristics”, page 207. 2. Fix minor bugs. 3. Update power consumption measures, Table 24-2 on page 208. 27.2 Changes from 4341B - 01/05 to 4341C - 03/05 1. Change to hardware security system description. Section “Hardware Security System”, page 20. 27.3 Changes from 4341C - 03/05 to 4341D - 04/05 1. Update to DAC gain information, Figure 15-2 on page 82. 2. Correction to BGA package pinout, Figure 4-1 on page 4. 3. Updated Ordering Information, Green product version changed to ROHS. (Green version not yet available) 27.4 Changes from 4341D - 04/05 to 4341E - 06/05 1. Added Green Packaging Information. Page 228 2. Modified operating conditions, Page 1. 27.5 Changes from 4341E - 06/05 to 4341F - 03/06 1. Added 8xSND2CxxxMP3B description with A/D converter. 236 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B 1. 2. 3. 4. Description ............................................................................................... 2 Typical Applications ................................................................................ 2 Block Diagram .......................................................................................... 3 Pin Description ......................................................................................... 4 4.1 Pinouts ..................................................................................................................... 4 4.2 ................................................................................................................................. 5 4.3 Signals...................................................................................................................... 6 4.4 Internal Pin Structure.............................................................................................. 12 5. Clock Controller ..................................................................................... 13 5.1 Oscillator ................................................................................................................ 13 5.2 X2 Feature.............................................................................................................. 14 5.3 PLL ......................................................................................................................... 14 5.4 Registers ................................................................................................................ 16 6. Program/Code Memory ......................................................................... 18 6.1 ROM Memory Architecture ..................................................................................... 19 6.2 Flash Memory Architecture .................................................................................... 19 6.3 Hardware Security System ..................................................................................... 20 6.4 Boot Memory Execution ......................................................................................... 20 6.5 Preventing Flash Corruption................................................................................... 21 6.6 Registers ................................................................................................................ 22 6.7 Hardware Bytes ...................................................................................................... 22 7. Data Memory .......................................................................................... 24 7.1 Internal Space ........................................................................................................ 24 7.2 External Space ....................................................................................................... 25 7.3 Dual Data Pointer ................................................................................................... 27 7.4 Registers ................................................................................................................ 29 8. 9. Special Function Registers ................................................................... 31 Interrupt System .................................................................................... 37 9.1 Interrupt System Priorities ...................................................................................... 37 9.2 External Interrupts .................................................................................................. 40 9.3 Registers ................................................................................................................ 41 10. Power Management ............................................................................... 47 10.1 Reset .................................................................................................................... 47 237 4341F–MP3–03/06 10.2 Reset Recommendation to Prevent Flash Corruption .......................................... 48 10.3 Idle Mode.............................................................................................................. 49 10.4 Power-down Mode ............................................................................................... 49 10.5 Registers .............................................................................................................. 51 11. Timers/Counters .................................................................................... 52 11.1 Timer/Counter Operations .................................................................................... 52 11.2 Timer Clock Controller.......................................................................................... 52 11.3 Timer 0 ................................................................................................................. 53 11.4 Timer 1 ................................................................................................................. 55 11.5 Interrupt ................................................................................................................ 56 11.6 Registers .............................................................................................................. 57 12. Watchdog Timer ..................................................................................... 60 12.1 Description ........................................................................................................... 60 12.2 Watchdog Clock Controller................................................................................... 60 12.3 Watchdog Operation ............................................................................................ 61 12.4 Registers .............................................................................................................. 62 13. MP3 Decoder .......................................................................................... 63 13.1 Decoder ................................................................................................................ 63 13.2 Audio Controls ...................................................................................................... 65 13.3 Decoding Errors ................................................................................................... 65 13.4 Frame Information ................................................................................................ 66 13.5 Ancillary Data ....................................................................................................... 66 13.6 Interrupt ................................................................................................................ 66 13.7 Registers .............................................................................................................. 69 14. Audio Output Interface .......................................................................... 74 14.1 Description ........................................................................................................... 74 14.2 Clock Generator ................................................................................................... 75 14.3 Data Converter ..................................................................................................... 75 14.4 Audio Buffer.......................................................................................................... 76 14.5 MP3 Buffer ........................................................................................................... 77 14.6 Interrupt Request.................................................................................................. 77 14.7 MP3 Song Playing ................................................................................................ 77 14.8 Registers .............................................................................................................. 78 15. DAC and PA Interface ............................................................................ 81 238 AT8xC51SND2C/MP3B 4341F–MP3–03/06 AT8xC51SND2C/MP3B 15.1 DAC ...................................................................................................................... 81 15.2 Power Amplifier .................................................................................................... 98 15.3 Audio Supplies and Start-up................................................................................. 99 16. Universal Serial Bus ............................................................................ 103 16.1 USB Mass Storage Class Bulk-Only Transport .................................................. 103 16.2 USB Device Firmware Upgrade (DFU)............................................................... 103 16.3 Description ......................................................................................................... 103 16.4 Configuration ...................................................................................................... 107 16.5 Read/Write Data FIFO........................................................................................ 109 16.6 Bulk/Interrupt Transactions ................................................................................ 110 16.7 Control Transactions .......................................................................................... 114 16.8 Isochronous Transactions .................................................................................. 114 16.9 Miscellaneous..................................................................................................... 116 16.10 Suspend/Resume Management ....................................................................... 117 16.11 USB Interrupt System....................................................................................... 119 16.12 Registers .......................................................................................................... 122 17. IDE/ATAPI Interface ............................................................................. 131 17.1 Description ......................................................................................................... 131 17.2 Registers ............................................................................................................ 133 18. MultiMedia Card Controller ................................................................. 134 18.1 Card Concept ..................................................................................................... 134 18.2 Bus Concept....................................................................................................... 134 18.3 Description ......................................................................................................... 139 18.4 Clock Generator ................................................................................................. 140 18.5 Command Line Controller .................................................................................. 140 18.6 Data Line Controller ........................................................................................... 142 18.7 Interrupt .............................................................................................................. 148 18.8 Registers ............................................................................................................ 150 19. Synchronous Peripheral Interface ..................................................... 156 19.1 Description ......................................................................................................... 157 19.2 Interrupt .............................................................................................................. 160 19.3 Configuration ...................................................................................................... 160 19.4 Registers ............................................................................................................ 166 20. Serial I/O Port ....................................................................................... 168 239 4341F–MP3–03/06 20.1 Mode Selection................................................................................................... 168 20.2 Baud Rate Generator ......................................................................................... 168 20.3 Synchronous Mode (Mode 0) ............................................................................. 169 20.4 Asynchronous Modes (Modes 1, 2 and 3).......................................................... 171 20.5 Multiprocessor Communication (Modes 2 and 3) ............................................... 175 20.6 Automatic Address Recognition ......................................................................... 175 20.7 Interrupt .............................................................................................................. 177 20.8 Registers ............................................................................................................ 178 21. Two-wire Interface (TWI) Controller ................................................... 181 21.1 Description ......................................................................................................... 181 21.2 Registers ............................................................................................................ 195 22. Analog to Digital Converter ................................................................ 199 22.1 Description ......................................................................................................... 199 22.2 Registers ............................................................................................................ 202 23. Keyboard Interface .............................................................................. 204 23.1 Description ......................................................................................................... 204 23.2 Registers ............................................................................................................ 205 24. Electrical Characteristics .................................................................... 207 24.1 Absolute Maximum Rating ................................................................................. 207 24.2 DC Characteristics ............................................................................................. 207 24.3 AC Characteristics.............................................................................................. 219 24.4 SPI Interface....................................................................................................... 224 25. Ordering Information ........................................................................... 234 26. Package Information ............................................................................ 235 26.1 CTBGA100 ......................................................................................................... 235 27. Datasheet Revision History ................................................................ 236 27.1 Changes from 4341A - 10/04 to 4341B - 01/05.................................................. 236 27.2 Changes from 4341B - 01/05 to 4341C - 03/05 ................................................. 236 27.3 Changes from 4341C - 03/05 to 4341D - 04/05 ................................................. 236 27.4 Changes from 4341D - 04/05 to 4341E - 06/05 ................................................. 236 27.5 Changes from 4341E - 06/05 to 4341F - 03/06 .................................................. 236 240 AT8xC51SND2C/MP3B 4341F–MP3–03/06 A tmel Corporation 2325 Orchard Parkway San Jose, CA 95131, USA Tel: 1(408) 441-0311 Fax: 1(408) 487-2600 Atmel Operations Memory 2325 Orchard Parkway San Jose, CA 95131, USA Tel: 1(408) 441-0311 Fax: 1(408) 436-4314 RF/Automotive Theresienstrasse 2 Postfach 3535 74025 Heilbronn, Germany Tel: (49) 71-31-67-0 Fax: (49) 71-31-67-2340 1150 East Cheyenne Mtn. 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Atmel ® , logo and combinations thereof, are registered trademarks, and Everywhere You Are® are the trademarks of Atmel Corporation or its subsidiaries. Other terms and product names may be trademarks of others. Printed on recycled paper. 4341F–MP3–03/06