Features • 80C52X2 Core (6 Clocks per Instruction) • • • • • • • • • • • • • • • • • • – Maximum Core Frequency 48 MHz in X1 Mode, 24 MHz in X2 Mode – Dual Data Pointer – Full-duplex Enhanced UART (EUART), TxD and Rxd are 5 Volt Tolerant – Three 16-bit Timer/Counters: T0, T1 and T2 – 256 Bytes of Scratchpad RAM 8/16/32-Kbyte On-chip ROM 512 byte or 32-Kbyte EEPROM(1) On-chip Expanded RAM (ERAM): 1024 Bytes Integrated Power Monitor (POR/PFD) to Supervise Internal Power Supply USB 2.0 Full Speed Compliant Module with Interrupt on Transfer Completion (12Mbps) – Endpoint 0 for Control Transfers: 32-byte FIFO – 6 Programmable Endpoints with In or Out Directions and with Bulk, Interrupt or Isochronous Transfers • Endpoint 1, 2, 3: 32-byte FIFO • Endpoint 4, 5: 2 x 64-byte FIFO with Double Buffering (Ping-pong Mode) – Suspend/Resume Interrupts – Power-on Reset and USB Bus Reset – 48 MHz DPLL for Full-speed Bus Operation – USB Bus Disconnection on Microcontroller Request 5 Channels Programmable Counter Array (PCA) with 16-bit Counter, High-speed Output, Compare/Capture, PWM and Watchdog Timer Capabilities Programmable Hardware Watchdog Timer (One-time Enabled with Reset-out): 50 ms to 6s at 4 MHz Keyboard Interrupt Interface on Port P1 (8 Bits) TWI (Two Wire Interface) 400Kbit/s SPI Interface (Master/Slave Mode) MISO,MOSI,SCK and SS are 5 Volt Tolerant 34 I/O Pins 4 Direct-drive LED Outputs with Programmable Current Sources: 2-6-10 mA Typical 4-level Priority Interrupt System (11 sources) Idle and Power-down Modes 0 to 32 MHz On-chip Oscillator with Analog PLL for 48 MHz Synthesis Industrial Temperature Range Low Voltage Range Supply: 2.7V to 3.6V Packages: Die SO28, QFN32, MLF48, TQFP64 Notes: 1. EEPROM only available on MLF48 1. Description AT83C5134/35/36 are high performance ROM versions of the 80C51 single-chip 8-bit microcontrollers with full speed USB functions. AT83C5134/35 is pin compatible with AT89C5130A 16Kbytes In-System Programmable Flash microcontrollers. 8-bit Microcontroller with Full Speed USB Device AT83C5134 AT83C5135 AT83C5136 This allows to use AT89C5130A for development, pre-production and flexibility, while using AT83C5134/35 for cost reduction in mass production. Similarly AT83C5136 is pin compatible with AT89C5131A 32-Kbytes Flash microcontroller. AT83C5134/35/36 features a full-speed USB module compatible with the USB specifications Version 2.0. This module integrates the USB transceivers and the Serial Interface Engine (SIE) with Digital Phase Locked Loop and 48 MHz clock recovery. USB Event detection logic (Reset and Suspend/Resume) and FIFO buffers supporting the mandatory control Endpoint (EP0) and 5 versatile Endpoints (EP1/EP2/EP3/EP4/EP5) with minimum software overhead are also part of the USB module. AT83C5134/35/36 retains the features of the Atmel 80C52 with extended ROM cpacity (8/16/32 Kbytes), 256 bytes of internal RAM, a 4-level interrupt system, two 16-bit timer/counters (T0/T1), a full duplex enhanced UART (EUART) and an on-chip oscillator. In addition, AT83C5134/35/36 has an on-chip expanded RAM of 1024 bytes (ERAM), a dualdata pointer, a 16-bit up/down Timer (T2), a Programmable Counter Array (PCA), up to 4 programmable LED current sources, a programmable hardware watchdog and a power-on reset. AT83C5134/35/36 has two software-selectable modes of reduced activity for further reduction in power consumption. In the idle mode the CPU is frozen while the timers, the serial ports and the interrupt system are still operating. In the power-down mode the RAM is saved, the peripheral clock is frozen, but the device has full wake-up capability through USB events or external interrupts. 2 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 XTAL1 XTAL2 EUART + BRG ALE 32Kx8 ROM SCK SDA MISO MOSI (1) (1) (1) (1) (1) (1) EEPROM* ERAM RAM 256x8 SCL T2 T2EX CEX ECI VDD VSS TxD (1) (1) (2) (2) SS RxD 3. Block Diagram 1Kx8 PCA 1Kx8 Timer2 TWI SPI TWI interface C51 CORE PSEN CPU EA Parallel I/O Ports & Ext. Bus Key Watch USB Board Dog D+ D- KIN P4 P3 P2 P1 INT1 (2) (2) P0 Port 0 Port 1 Port 2 Port 3 Port 4 (2) (2) T1 (2) INT Ctrl INT0 Timer 0 Timer 1 RST WR (2) T0 RD * EEPROM only available in MLF48 Notes: 1. Alternate function of Port 1 2. Alternate function of Port 3 3. Alternate function of Port 4 3 7683C–USB–11/07 4. Pinout Description Pinout NC P1.0/T2/KIN0 P1.1/T2EX/KIN1/SS P1.2/ECI/KIN2 P1.3/CEX0/KIN3 P0.0/AD0 P1.4/CEX1/KIN4 P2.1/A9 P2.0/A8 P2.2/A10 P1.5/CEX2/KIN5/MISO P1.6/CEX3/KIN6/SCK AT83C5134/35/36 64-pin VQFP Pinout NC Figure 4-1. P4.1/SDA P4.0/SCL P1.7/CEX4/KIN7/MOSI 4.1 64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 NC P2.3/A11 1 2 48 47 P2.4/A12 3 46 NC P0.1/AD1 P2.5/A13 XTAL2 XTAL1 4 45 P0.2/AD2 5 6 44 43 RST P0.3/AD3 VSS P2.6/A14 7 42 P2.7/A15 VDD AVDD 8 9 41 40 VQFP64 10 39 NC 11 AVSS 12 NC 13 38 P3.0/RxD 36 35 NC NC 37 14 15 16 NC NC P0.4/AD4 P3.7/RD/LED3 P0.5/AD5 P0.6/AD6 P0.7/AD7 P3.6/WR/LED2 34 NC 33 NC 4 P3.4/T0 P3.5/T1/LED1 NC P3.2/INT0 P3.3/INT1/LED0 P3.1/TxD ALE PSEN EA VREF NC D- D+ PLLF NC NC 17 18 19 20 21 22 23 24 25 26 27 28 29 30 3132 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 P4.1/SDA P2.3/A11 P2.4/A12 P1.1/T2EX/KIN1/SS P1.3/CEX0/KIN3 P1.2/ECI/KIN2 P0.0/AD0 P1.4/CEX1/KIN4 P2.0/A8 P1.5/CEX2/KIN5/MISO P2.2/A10 P2.1/A9 P1.6/CEX3/KIN6/SCK P1.7/CEX4/KIN7/MOSI AT83C5134/35/36 48-pin MLF Pinout P4.0/SCL Figure 4-2. 48 47 46 45 44 43 42 41 40 39 38 37 36 2 35 3 34 1 P2.5/A13 4 33 XTAL2 XTAL1 5 32 RST P0.3/AD3 6 31 VSS P2.6/A14 P2.7/A15 7 30 P0.4/AD4 9 29 28 P3.7/RD/LED3 VDD AVDD 10 27 P0.6/AD6 MLF48 8 P0.5/AD5 P0.7/AD7 P3.6/WR/LED2 P3.5/T1/LED1 P3.4/T0 P3.3/INT1/LED0 P3.2/INT0 ALE PSEN P3.1/TxD VREF EA D+ D- PLLF AVSS 11 26 P3.0/RxD 12 25 13 14 15 16 17 18 19 20 21 22 23 24 Figure 4-3. P1.0/T2/KIN0 P0.1/AD1 P0.2/AD2 AT83C5134/35/36 28-pin SO Pinout P1.5/CEX2/KIN5/MISO 1 28 P1.4/CEX1/KIN4 P1.6/CEX3/KIN6/SCK 2 P1.7/CEX4/KIN7/MOSI 3 27 26 P1.3/CEX0/KIN3 P4.0/SCL 4 25 P1.1/T2EX/KIN1/SS 24 23 P1.0/T2/KIN0 P4.1/SDA 5 XTAL2 6 XTAL1 7 VDD 8 AVSS 9 P3.0/RxD 10 11 PLLF D- 12 D+ VREF 13 14 SO28 P1.2/ECI/KIN2 RST 22 VSS 21 20 P3.7/RD/LED3 P3.6/WR/LED2 19 18 P3.4/T0 P3.5/T1/LED1 17 P3.3/INT1/LED0 16 P3.2/INT0 15 P3.1/TxD 5 7683C–USB–11/07 Figure 4-4. P1.2/ECI/KIN2 P1.1/T2EX/KIN1/SS P1.3/CEX0/KIN3 P1.5/CEX2/KIN5/MISO P1.4/CEX1/KIN4 P1.7/CEX4/KIN7/MOSI P1.6/CEX3/KIN6/SCK P4.0/SCL AT83C5134/35/36 32-pin QFN Pinout 32 31 30 29 28 27 26 25 P4.1/SDA 1 24 P1.0/T2/KIN0 XTAL2 2 23 RST XTAL1 3 22 NC VDD 4 21 VSS AVDD 5 20 VSS AVSS 6 19 P3.7/RD/LED3 P3.0/RxD 7 18 P3.6/WR/LED2 PLLF 8 17 P3.5/T1/LED1 QFN32 P3.4/T0 P3.2/INT0 P3.3/INT1/LED0 UVSS P3.1/TxD VREF D- D+ 9 10 11 12 13 14 15 16 Note : The metal plate can be connected to Vss 4.2 Signals All the AT83C5134/35/36 signals are detailed by functionality on Table 4-1 through Table 4-12. Table 4-1. Keypad Interface Signal Description Signal Name Type KIN[7:0) I Table 4-2. Description Keypad Input Lines Holding one of these pins high or low for 24 oscillator periods triggers a keypad interrupt if enabled. Held line is reported in the KBCON register. P1[7:0] Programmable Counter Array Signal Description Signal Name Type ECI I Description External Clock Input Capture External Input CEX[4:0] Alternate Function I/O Compare External Output Alternate Function P1.2 P1.3 P1.4 P1.5 P1.6 P1.7 6 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 Table 4-3. Serial I/O Signal Description Signal Name Type RxD I TxD O Table 4-4. Signal Name Description Serial Input The serial input for Extended UART. This I/O is 5 Volt Tolerant. Serial Output The serial output for Extended UART. This I/O is 5 Volt Tolerant. Alternate Function P3.0 P3.1 Timer 0, Timer 1 and Timer 2 Signal Description Type Description Alternate Function Timer 0 Gate Input INT0 serves as external run control for timer 0, when selected by GATE0 bit in TCON register. INT0 I External Interrupt 0 INT0 input set IE0 in the TCON register. If bit IT0 in this register is set, bits IE0 are set by a falling edge on INT0. If bit IT0 is cleared, bits IE0 is set by a low level on INT0. P3.2 Timer 1 Gate Input INT1 serves as external run control for Timer 1, when selected by GATE1 bit in TCON register. INT1 I T0 I Timer Counter 0 External Clock Input When Timer 0 operates as a counter, a falling edge on the T0 pin increments the count. P3.4 T1 I Timer/Counter 1 External Clock Input When Timer 1 operates as a counter, a falling edge on the T1 pin increments the count. P3.5 T2 T2EX Table 4-5. Signal Name LED[3:0] External Interrupt 1 INT1 input set IE1 in the TCON register. If bit IT1 in this register is set, bits IE1 are set by a falling edge on INT1. If bit IT1 is cleared, bits IE1 is set by a low level on INT1. I Timer/Counter 2 External Clock Input O Timer/Counter 2 Clock Output I Timer/Counter 2 Reload/Capture/Direction Control Input P3.3 P1.0 P1.1 LED Signal Description Type O Description Direct Drive LED Output These pins can be directly connected to the Cathode of standard LEDs without external current limiting resistors. The typical current of each output can be programmed by software to 2, 6 or 10 mA. Several outputs can be connected together to get higher drive capabilities. Alternate Function P3.3 P3.5 P3.6 P3.7 7 7683C–USB–11/07 Table 4-6. TWI Signal Description Signal Name Type SCL I/O SCL: TWI Serial Clock SCL output the serial clock to slave peripherals. SCL input the serial clock from master. P4.0 SDA I/O SDA: TWI Serial Data SCL is the bidirectional TWI data line. P4.1 Table 4-7. Alternate Function Description SPI Signal Description Signal Name Type SS I/O Alternate Function Description SS: SPI Slave Select . This I/O is 5 Volt tolerant P1.1 MISO: SPI Master Input Slave Output line MISO I/O SCK I/O When SPI is in master mode, MISO receives data from the slave peripheral. When SPI is in slave mode, MISO outputs data to the master controller. This I/O is 5 Volt tolerant P1.5 SCK: SPI Serial Clock SCK outputs clock to the slave peripheral or receive clock from the master. P1.6 This I/O is 5 Volt tolerant. MOSI: SPI Master Output Slave Input line MOSI I/O When SPI is in master mode, MOSI outputs data to the slave peripheral. When SPI is in slave mode, MOSI receives data from the master controller. P1.7 This I/O is 5 Volt tolerant. Table 4-8. Signal Name P0[7:0] P1[7:0] Ports Signal Description Type I/O I/O Description Port 0 P0 is an 8-bit open-drain bidirectional I/O port. Port 0 pins that have 1s written to them float and can be used as high impedance inputs. To avoid any parasitic current consumption, Floating P0 inputs must be pulled to VDD or VSS. Port 1 P1 is an 8-bit bidirectional I/O port with internal pull-ups. Alternate Function AD[7:0] KIN[7:0] T2 T2EX ECI CEX[4:0] P2[7:0] 8 I/O Port 2 P2 is an 8-bit bidirectional I/O port with internal pull-ups. A[15:8] AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 Signal Name Type Description Alternate Function LED[3:0] RxD TxD P3[7:0] I/O Port 3 P3 is an 8-bit bidirectional I/O port with internal pull-ups. P4[1:0] I/O Port 4 P4 is an 2-bit open port. Table 4-9. INT0 INT1 T0 T1 WR RD SCL SDA Clock Signal Description Signal Name Type XTAL1 I 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. - XTAL2 O Output of the on-chip inverting oscillator amplifier To use the internal oscillator, a crystal/resonator circuit is connected to this pin. If an external oscillator is used, leave XTAL2 unconnected. - PLLF I PLL Low Pass Filter input Receives the RC network of the PLL low pass filter (See Figure 5-1 on page 11 ). - Table 4-10. Alternate Function USB Signal Description Signal Name Type D+ I/O D- I/O VREF O Table 4-11. Description Description USB Data + signal Set to high level under reset. USB Data - signal Set to low level under reset. USB Reference Voltage Connect this pin to D+ using a 1.5 kΩ resistor to use the Detach function. Alternate Function - - - System Signal Description Signal Name Type AD[7:0] I/O A[15:8] I/O Description Multiplexed Address/Data LSB for external access Data LSB for Slave port access (used for 8-bit and 16-bit modes) Address Bus MSB for external access Data MSB for Slave port access (used for 16-bit mode only) Alternate Function P0[7:0] P2[7:0] 9 7683C–USB–11/07 Signal Name Type RD I/O Alternate Function Description Read Signal Read signal asserted during external data memory read operation. P3.7 Control input for slave port read access cycles. WR I/O Write Signal Write signal asserted during external data memory write operation. P3.6 Control input for slave write access cycles. RST I/O Reset Holding this pin low for 64 oscillator periods while the oscillator is running resets the device. The Port pins are driven to their reset conditions when a voltage lower than VIL is applied, whether or not the oscillator is running. This pin has an internal pull-up resistor which allows the device to be reset by connecting a capacitor between this pin and VSS. Asserting RST when the chip is in Idle mode or Power-down mode returns the chip to normal operation. This pin is set to 0 for at least 12 oscillator periods when an internal reset occurs (hardware watchdog or Power monitor). ALE O Address Latch Enable Output The falling edge of ALE strobes the address into external latch. This signal is active only when reading or writing external memory using MOVX instructions. PSEN O Program Strobe Enable / Hardware conditions Input for ISP - - - Used as input under reset to detect external hardware conditions of ISP mode External Access Enable EA This pin must be held low to force the device to fetch code from external program memory starting at address 0000h. It is latched during reset and cannot be dynamically changed during operation. I Table 4-12. - Power Signal Description Signal Name Type Description AVSS GND Alternate Ground AVSS is used to supply the on-chip PLL and the USB PAD. - AVDD PWR Alternate Supply Voltage AVDD is used to supply the on-chip PLL and the USB PAD. - VSS GND Digital Ground VSS is used to supply the buffer ring and the digital core. - VDD PWR Alternate Function Digital Supply Voltage VDD is used to supply the buffer ring on all versions of the device. It is also used to power the on-chip voltage regulator of the Standard versions or the digital core of the Low Power versions. - USB pull-up Controlled Output VREF 10 O VREF is used to control the USB D+ 1.5 kΩ pull up. The Vref output is in high impedance when the bit DETACH is set in the USBCON register. - AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 5. Typical Application 5.1 Recommended External components All the external components described in the figure below must be implemented as close as possible from the microcontroller package. The following figure represents the typical wiring schematic. Figure 5-1. Typical Application VDD 100nF VSS VSS VSS AVDD VDD 1.5K USB 100nF 4.7µF VRef AT83C5134/35/3 VBUS 27R D+ D+ XTAL1 27R D- 22pF DQ 22pF GND XTAL2 VSS VSS AVSS 560 150pF VSS PLLF 820pF VSS VSS VSS 11 7683C–USB–11/07 5.2 PCB Recommandations Figure 5-2. USB Pads Components must be close to the microcontroller Wires must be routed in Parallel and must be as short as possible VRef D+ D- USB Connector If possible, isolate D+ and D- signals from other signals with ground wires Note: No sharp angle in above drawing. Figure 5-3. USB PLL AVss PLLF C2 R microcontroller C1 Components must be close to the Isolate filter components with a ground wire 12 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 6. Clock Controller 6.1 Introduction The AT83C5134/35/36 clock controller is based on an on-chip oscillator feeding an on-chip Phase Lock Loop (PLL). All the internal clocks to the peripherals and CPU core are generated by this controller. The AT83C5134/35/36 X1 and X2 pins are the input and the output of a single-stage on-chip inverter (see Figure 6-1) that can be configured with off-chip components as a Pierce oscillator (see Figure 6-2). Value of capacitors and crystal characteristics are detailed in the section “DC Characteristics”. The X1 pin can also be used as input for an external 48 MHz clock. The clock controller outputs three different clocks as shown in Figure 6-1: • a clock for the CPU core • a clock for the peripherals which is used to generate the Timers, PCA, WD, and Port sampling clocks • a clock for the USB controller These clocks are enabled or disabled depending on the power reduction mode as detailed in Section “Power Management”, page 135. Figure 6-1. Oscillator Block Diagram ÷2 0 Peripheral Clock 1 CPU Core Clock PLL X1 X2 IDL CKCON.0 PCON.0 0 1 USB Clock X2 6.2 EXT48 PD PLLCON.2 PCON.1 Oscillator Two clock sources are available for CPU: • Crystal oscillator on X1 and X2 pins: Up to 32 MHz • External 48 MHz clock on X1 pin 13 7683C–USB–11/07 In order to optimize the power consumption, the oscillator inverter is inactive when the PLL output is not selected for the USB device. Figure 6-2. Crystal Connection X1 C1 Q C2 VSS 6.3 6.3.1 X2 PLL PLL Description The AT83C5134/35/36 PLL is used to generate internal high frequency clock (the USB Clock) synchronized with an external low-frequency (the Peripheral Clock). The PLL clock is used to generate the USB interface clock. Figure 6-3 shows the internal structure of the PLL. The PFLD block is the Phase Frequency Comparator and Lock Detector. This block makes the comparison between the reference clock coming from the N divider and the reverse clock coming from the R divider and generates some pulses on the Up or Down signal depending on the edge position of the reverse clock. The PLLEN bit in PLLCON register is used to enable the clock generation. When the PLL is locked, the bit PLOCK in PLLCON register (see Figure 6-3) is set. The CHP block is the Charge Pump that generates the voltage reference for the VCO by injecting or extracting charges from the external filter connected on PLLF pin (see Figure 6-4). Value of the filter components are detailed in the Section “DC Characteristics”. The VCO block is the Voltage Controlled Oscillator controlled by the voltage VREF produced by the charge pump. It generates a square wave signal: the PLL clock. Figure 6-3. PLL Block Diagram and Symbol PLLF PLLCON.1 PLLEN N divider OSC CLOCK N3:0 Up PFLD CHP Vref VCO USB Clock Down PLOCK PLLCON.0 R divider R3:0 OSCclk × ( R + 1 ) USBclk = ----------------------------------------------N+1 14 USB CLOCK USB Clock Symbol AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 Figure 6-4. PLL Filter Connection PLLF R C2 C1 VSS VSS The typical values are: R = 560 Ω, C1 = 820 pf, C2 = 150 pF. 6.3.2 PLL Programming The PLL is programmed using the flow shown in Figure 6-5. As soon as clock generation is enabled user must wait until the lock indicator is set to ensure the clock output is stable. Figure 6-5. PLL Programming Flow PLL Programming Configure Dividers N3:0 = xxxxb R3:0 = xxxxb Enable PLL PLLEN = 1 PLL Locked? LOCK = 1? 6.3.3 Divider Values To generate a 48 MHz clock using the PLL, the divider values have to be configured following the oscillator frequency. The typical divider values are shown in Table 6-1. Table 6-1. Typical Divider Values Oscillator Frequency R+1 N+1 PLLDIV 3 MHz 16 1 F0h 6 MHz 8 1 70h 8 MHz 6 1 50h 12 MHz 4 1 30h 16 MHz 3 1 20h 18 MHz 8 3 72h 20 MHz 12 5 B4h 24 MHz 2 1 10h 15 7683C–USB–11/07 6.4 Oscillator Frequency R+1 N+1 PLLDIV 32 MHz 3 2 21h 40 MHz 12 10 B9h Registers Table 6-2. CKCON0 (S:8Fh) Clock Control Register 0 7 6 5 4 3 2 1 0 TWIX2 WDX2 PCAX2 SIX2 T2X2 T1X2 T0X2 X2 Bit Number Bit Mnemonic Description TWIX2 TWI Clock This control bit is validated when the CPU clock X2 is set. When X2 is low, this bit has no effect. Clear to select 6 clock periods per peripheral clock cycle. Set to select 12 clock periods per peripheral clock cycle. WDX2 Watchdog Clock This control bit is validated when the CPU clock X2 is set. When X2 is low, this bit has no effect. Clear to select 6 clock periods per peripheral clock cycle. Set to select 12 clock periods per peripheral clock cycle. PCAX2 Programmable Counter Array Clock This control bit is validated when the CPU clock X2 is set. When X2 is low, this bit has no effect. Clear to select 6 clock periods per peripheral clock cycle. Set to select 12 clock periods per peripheral clock cycle. SIX2 Enhanced UART Clock (Mode 0 and 2) This control bit is validated when the CPU clock X2 is set. When X2 is low, this bit has no effect. Clear to select 6 clock periods per peripheral clock cycle. Set to select 12 clock periods per peripheral clock cycle. T2X2 Timer2 Clock This control bit is validated when the CPU clock X2 is set. When X2 is low, this bit has no effect. Clear to select 6 clock periods per peripheral clock cycle. Set to select 12 clock periods per peripheral clock cycle. T1X2 Timer1 Clock This control bit is validated when the CPU clock X2 is set. When X2 is low, this bit has no effect. Clear to select 6 clock periods per peripheral clock cycle. Set to select 12 clock periods per peripheral clock cycle. 1 T0X2 Timer0 Clock This control bit is validated when the CPU clock X2 is set. When X2 is low, this bit has no effect. Clear to select 6 clock periods per peripheral clock cycle. Set to select 12 clock periods per peripheral clock cycle. 0 X2 7 6 5 4 3 2 System Clock Control bit Clear to select 12 clock periods per machine cycle (STD mode, FCPU = FPER = FOSC/2). Set to select 6 clock periods per machine cycle (X2 mode, FCPU = FPER = FOSC). Reset Value = 0000 0000b 16 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 Table 6-3. CKCON1 (S:AFh) Clock Control Register 1 7 6 5 4 3 2 1 0 - - - - - - - SPIX2 Bit Number Bit Mnemonic Description 7-1 - 0 SPIX2 Reserved The value read from this bit is always 0. Do not set this bit. SPI Clock This control bit is validated when the CPU clock X2 is set. When X2 is low, this bit has no effect. Clear to select 6 clock periods per peripheral clock cycle. Set to select 12 clock periods per peripheral clock cycle. Reset Value = 0000 0000b Table 6-4. PLLCON (S:A3h) PLL Control Register 7 6 5 4 3 2 1 0 - - - - - EXT48 PLLEN PLOCK Bit Number Bit Mnemonic Description 7-3 - 2 EXT48 External 48 MHz Enable Bit Set this bit to bypass the PLL and disable the crystal oscillator. Clear this bit to select the PLL output as USB clock and to enable the crystal oscillator. 1 PLLEN PLL Enable Bit Set to enable the PLL. Clear to disable the PLL. 0 PLOCK PLL Lock Indicator Set by hardware when PLL is locked. Clear by hardware when PLL is unlocked. Reserved The value read from this bit is always 0. Do not set this bit. Reset Value = 0000 0000b Table 6-5. PLLDIV (S:A4h) PLL Divider Register 7 6 5 4 3 2 1 0 R3 R2 R1 R0 N3 N2 N1 N0 Bit Number Bit Mnemonic Description 7-4 R3:0 PLL R Divider Bits 3-0 N3:0 PLL N Divider Bits Reset Value = 0000 0000 17 7683C–USB–11/07 7. SFR Mapping The Special Function Registers (SFRs) of the AT83C5134/35/36 fall into the following categories: • C51 core registers: ACC, B, DPH, DPL, PSW, SP • I/O port registers: P0, P1, P2, P3, P4 • Timer registers: T2CON, T2MOD, TCON, TH0, TH1, TH2, TMOD, TL0, TL1, TL2, RCAP2L, RCAP2H • Serial I/O port registers: SADDR, SADEN, SBUF, SCON • PCA (Programmable Counter Array) registers: CCON, CMOD, CCAPMx, CL, CH, CCAPxH, CCAPxL (x: 0 to 4) • Power and clock control registers: PCON • Hardware Watchdog Timer registers: WDTRST, WDTPRG • Interrupt system registers: IEN0, IPL0, IPH0, IEN1, IPL1, IPH1 • Keyboard Interface registers: KBE, KBF, KBLS • LED register: LEDCON • Two Wire Interface (TWI) registers: SSCON, SSCS, SSDAT, SSADR • Serial Port Interface (SPI) registers: SPCON, SPSTA, SPDAT • USB registers: Uxxx (17 registers) • PLL registers: PLLCON, PLLDIV • BRG (Baud Rate Generator) registers: BRL, BDRCON • Others: AUXR, AUXR1, CKCON0, CKCON1 18 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 The table below shows all SFRs with their address and their reset value. Table 7-1. SFR Descriptions Bit Addressable Non-Bit Addressable 0/8 1/9 F8h UEPINT 0000 0000 CH CCAP0H CCAP1H CCAP2H CCAP3H CCAP4H 0000 0000 XXXX XXXX XXXX XXXX XXXX XXXX XXXX XXXX XXXX XXXX F0h B 0000 0000 0000 0000 E8h E0h D8h A0h 98h 90h 88h 80h Note: 6/E 7/F FFh F7h CL CCAP0L CCAP1L CCAP2L CCAP3L CCAP4L 0000 0000 XXXX XXXX XXXX XXXX XXXX XXXX XXXX XXXX XXXX XXXX UBYCTLX 0000 0000 UBYCTHX 0000 0000 EFh E7h CMOD CCAPM0 CCAPM1 CCAPM2 CCAPM3 CCAPM4 00XX X000 X000 0000 X000 0000 X000 0000 X000 0000 X000 0000 UEPCONX 1000 0000 UEPRST 0000 0000 TL2 0000 0000 TH2 0000 0000 UEPSTAX 0000 0000 UEPDATX 0000 0000 CFh UEPNUM 0000 0000 C7h T2CON 0000 0000 A8h 5/D CCON C8h B0h 4/C 00X0 0000 PSW 0000 0000 B8h 3/B LEDCON ACC 0000 0000 D0h C0h 2/A T2MOD XXXX XX00 P4 XXXX 1111 DFh D7h RCAP2L 0000 0000 RCAP2H 0000 0000 UEPIEN 0000 0000 SPCON SPSTA SPDAT 0001 0100 0000 0000 XXXX XXXX USBADDR 1000 0000 UFNUMH 0000 0000 USBCON 0000 0000 USBINT 0000 0000 USBIEN 0000 0000 IPL0 SADEN X000 000 0000 0000 UFNUML 0000 0000 P3 IEN1 X0XX X000 IPL1 IPH1 IPH0 X0XX X000 X0XX X000 X000 0000 1111 1111 BFh IEN0 SADDR CKCON1 0000 0000 0000 0000 0000 0000 P2 AUXR1 1111 1111 XXXX X0X0 PLLCON XXXX XX00 PLLDIV 0000 0000 WDTRST WDTPRG XXXX XXXX XXXX X000 SCON SBUF BRL BDRCON KBLS KBE KBF 0000 0000 XXXX XXXX 0000 0000 XXX0 0000 0000 0000 0000 0000 0000 0000 P1 SSCON SSCS SSDAT SSADR 1111 1111 0000 0000 1111 1000 1111 1111 1111 1110 AUXR XX0X 0000 TCON TMOD TL0 TL1 TH0 TH1 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 P0 1111 1111 SP 0000 0111 DPL 0000 0000 DPH 0000 0000 0/8 1/9 2/A 3/B 6/E A7h 97h CKCON0 0000 0000 PCON 5/D AFh 9Fh 00X1 0000 4/C B7h 8Fh 87h 7/F 1. FCON access is reserved for the Flash API and ISP software. Reserved The Special Function Registers (SFRs) of the AT89C5131 fall into the following categories: 19 7683C–USB–11/07 Table 7-2. C51 Core SFRs Mnemonic Add Name ACC E0h Accumulator B F0h B Register PSW D0h Program Status Word SP 81h DPL 82h 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 Stack Pointer LSB of SPX Data Pointer Low byte LSB of DPTR DPH 83h Data Pointer High byte MSB of DPTR Table 7-3. Table 7-4. I/O Port SFRs Mnemonic Add Name P0 80h Port 0 P1 90h Port 1 P2 A0h Port 2 P3 B0h Port 3 P4 C0h Port 4 (2bits) Timer SFR’s Mnemonic Add Name TH0 8Ch Timer/Counter 0 High byte TL0 8Ah Timer/Counter 0 Low byte TH1 8Dh Timer/Counter 1 High byte TL1 8Bh Timer/Counter 1 Low byte TH2 CDh Timer/Counter 2 High byte TL2 CCh Timer/Counter 2 Low byte TCON 88h TMOD 20 7 6 5 4 3 2 1 0 Timer/Counter 0 and 1 control TF1 TR1 TF0 TR0 IE1 IT1 IE0 IT0 89h Timer/Counter 0 and 1 Modes GATE1 C/T1# M11 M01 GATE0 C/T0# M10 M00 T2CON C8h Timer/Counter 2 control TF2 EXF2 RCLK TCLK EXEN2 TR2 C/T2# CP/RL2# T2MOD C9h Timer/Counter 2 Mode T2OE DCEN AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 Table 7-4. Timer SFR’s (Continued) Mnemonic Add Name RCAP2H CBh Timer/Counter 2 Reload/Capture High byte RCAP2L CAh Timer/Counter 2 Reload/Capture Low byte WDTRST A6h WatchDog Timer Reset WDTPRG A7h WatchDog Timer Program Table 7-5. Add Name SCON 98h Serial Control SBUF 99h Serial Data Buffer SADEN B9h Slave Address Mask SADDR A9h Slave Address 5 4 3 2 1 0 S2 S1 S0 7 6 5 4 3 2 1 0 FE/SM0 SM1 SM2 REN TB8 RB8 TI RI 7 6 5 4 3 2 1 0 BRR TBCK RBCK SPD SRC Baud Rate Generator SFR’s Mnemonic Add Name BRL 9Ah Baud Rate Reload BDRCON 9Bh Baud Rate Control Table 7-7. 6 Serial I/O Port SFR’s Mnemonic Table 7-6. 7 PCA SFR’s Mnemonic Add Name CCON D8h PCA Timer/Counter Control CMOD D9h PCA Timer/Counter Mode CL E9h PCA Timer/Counter Low byte CH F9h PCA Timer/Counter High byte CCAPM 1 DAh PCA Timer/Counter Mode 0 ECOM0 CAPP0 CAPN0 CCAPM 2 DBh PCA Timer/Counter Mode 1 ECOM1 CAPP1 CAPN1 DCh PCA Timer/Counter Mode 2 ECOM2 CAPP2 DDh PCA Timer/Counter Mode 3 ECOM3 DEh PCA Timer/Counter Mode 4 ECOM4 7 6 CF CR CIDL WDTE 5 4 3 2 1 0 CCF4 CCF3 CCF2 CCF1 CCF0 CPS1 CPS0 ECF MAT0 TOG0 PWM0 ECCF0 MAT1 TOG1 PWM1 ECCF1 CAPN2 MAT2 TOG2 PWM2 ECCF2 CAPP3 CAPN3 MAT3 TOG3 PWM3 ECCF3 CAPP4 CAPN4 MAT4 TOG4 PWM4 ECCF4 CCAPM 0 CCAPM 3 CCAPM 4 21 7683C–USB–11/07 Table 7-7. PCA SFR’s Mnemonic Add Name CCAP0 H PCA Compare Capture Module 0 H CCAP1 H FAh CCAP2 H FCh CCAP3 H FBh FDh FEh CCAP4 H 7 6 5 4 3 2 1 0 PCA Compare Capture Module 1 H CCAP0H7 CCAP0H6 CCAP0H5 CCAP0H4 CCAP0H3 CCAP0H2 CCAP0H1 CCAP0H0 PCA Compare Capture Module 2 H CCAP2H7 CCAP2H6 CCAP2H5 CCAP2H4 CCAP2H3 CCAP2H2 CCAP2H1 CCAP2H0 PCA Compare Capture Module 3 H CCAP1H7 CCAP1H6 CCAP1H5 CCAP1H4 CCAP1H3 CCAP1H2 CCAP1H1 CCAP1H0 CCAP3H7 CCAP3H6 CCAP3H5 CCAP3H4 CCAP3H3 CCAP3H2 CCAP3H1 CCAP3H0 CCAP4H7 CCAP4H6 CCAP4H5 CCAP4H4 CCAP4H3 CCAP4H2 CCAP4H1 CCAP4H0 PCA Compare Capture Module 4 H PCA Compare Capture Module 0 L CCAP0L EAh CCAP1L EBh CCAP2L ECh CCAP3L EDh CCAP4L EEh PCA Compare Capture Module 1 L CCAP0L7 CCAP0L6 CCAP0L5 CCAP0L4 CCAP0L3 CCAP0L2 CCAP0L1 CCAP0L0 PCA Compare Capture Module 2 L CCAP1L7 CCAP1L6 CCAP1L5 CCAP1L4 CCAP1L3 CCAP1L2 CCAP1L1 CCAP1L0 CCAP2L7 CCAP2L6 CCAP2L5 CCAP2L4 CCAP2L3 CCAP2L2 CCAP2L1 CCAP2L0 CCAP3L7 CCAP3L6 CCAP3L5 CCAP3L4 CCAP3L3 CCAP3L2 CCAP3L1 CCAP3L0 CCAP4L7 CCAP4L6 CCAP4L5 CCAP4L4 CCAP4L3 CCAP4L2 CCAP4L1 CCAP4L0 PCA Compare Capture Module 3 L PCA Compare Capture Module 4 L Table 7-8. Interrupt SFR’s Mnemonic Add Name IEN0 A8h Interrupt Enable Control 0 IEN1 B1h Interrupt Enable Control 1 EUSB IPL0 B8h Interrupt Priority Control Low 0 PPCL PT2L PSL IPH0 B7h Interrupt Priority Control High 0 PPCH PT2H PSH IPL1 B2h Interrupt Priority Control Low 1 IPH1 B3h Interrupt Priority Control High 1 Table 7-9. 22 6 5 4 3 2 1 0 EA EC ET2 ES ET1 EX1 ET0 EX0 ESPI ETWI EKB PT1L PX1L PT0L PX0L PT1H PX1H PT0H PX0H PUSBL PSPIL PTWIL PKBL PUSBH PSPIH PTWIH PKBH PLL SFRs Mnemonic Add Name PLLCON A3h PLL Control PLLDIV A4h PLL Divider Table 7-10. 7 7 6 R3 5 R2 4 R1 3 R0 N3 2 1 0 EXT48 PLLEN PLOCK N2 N1 N0 Keyboard SFRs Mnemonic Add Name 7 6 5 4 3 2 1 0 KBF 9Eh Keyboard Flag Register KBF7 KBF6 KBF5 KBF4 KBF3 KBF2 KBF1 KBF0 KBE 9Dh Keyboard Input Enable Register KBE7 KBE6 KBE5 KBE4 KBE3 KBE2 KBE1 KBE0 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 Table 7-10. Keyboard SFRs Mnemonic Add Name KBLS 9Ch Keyboard Level Selector Register Table 7-11. 7 6 5 4 3 2 1 0 KBLS7 KBLS6 KBLS5 KBLS4 KBLS3 KBLS2 KBLS1 KBLS0 7 6 5 4 3 2 1 0 TWI SFRs Mnemonic Add Name SSCON 93h Synchronous Serial Control CR2 SSIE STA STO SI AA CR1 CR0 SSCS 94h Synchronous Serial Control-Status SC4 SC3 SC2 SC1 SC0 - - - SSDAT 95h Synchronous Serial Data SD7 SD6 SD5 SD4 SD3 SD2 SD1 SD0 SSADR 96h Synchronous Serial Address A7 A6 A5 A4 A3 A2 A1 A0 7 6 5 4 3 2 1 0 Table 7-12. SPI SFRs Mnemonic Add Name SPCON C3h Serial Peripheral Control SPR2 SPEN SSDIS MSTR CPOL CPHA SPR1 SPR0 SPSTA C4h Serial Peripheral Status-Control SPIF WCOL SSERR MODF - - - - SPDAT C5h Serial Peripheral Data R7 R6 R5 R4 R3 R2 R1 R0 Table 7-13. USB SFR’s Mnemonic Add Name 7 6 5 4 3 2 1 0 USBCON BCh USB Global Control USBE SUSPCLK SDRMWU P DETACH UPRSM RMWUPE CONFG FADDEN USBADDR C6h USB Address FEN UADD6 UADD5 UADD4 UADD3 UADD2 UADD1 UADD0 USBINT BDh USB Global Interrupt - - WUPCPU EORINT SOFINT - - SPINT USBIEN BEh USB Global Interrupt Enable - - EWUPCP U EEORINT ESOFINT - - ESPINT UEPNUM C7h USB Endpoint Number - - - - EPNUM3 EPNUM2 EPNUM1 EPNUM0 UEPCONX D4h USB Endpoint X Control EPEN - - - DTGL EPDIR EPTYPE1 EPTYPE0 UEPSTAX CEh USB Endpoint X Status DIR RXOUTB1 STALLRQ TXRDY STLCRC RXSETUP RXOUTB0 TXCMP UEPRST D5h USB Endpoint Reset - - EP5RST EP4RST EP3RST EP2RST EP1RST EP0RST UEPINT F8h USB Endpoint Interrupt - - EP5INT EP4INT EP3INT EP2INT EP1INT EP0INT UEPIEN C2h USB Endpoint Interrupt Enable - - EP5INTE EP4INTE EP3INTE EP2INTE EP1INTE EP0INTE UEPDATX CFh USB Endpoint X FIFO Data FDAT7 FDAT6 FDAT5 FDAT4 FDAT3 FDAT2 FDAT1 FDAT0 23 7683C–USB–11/07 Table 7-13. USB SFR’s Mnemonic Add Name 7 6 5 4 3 2 1 0 UBYCTLX E2h USB Byte Counter Low (EP X) BYCT7 BYCT6 BYCT5 BYCT4 BYCT3 BYCT2 BYCT1 BYCT0 UBYCTHX E3h USB Byte Counter High (EP X) - - - - - BYCT10 BYCT9 BYCT8 UFNUML BAh USB Frame Number Low FNUM7 FNUM6 FNUM5 FNUM4 FNUM3 FNUM2 FNUM1 FNUM0 UFNUMH BBh USB Frame Number High - - CRCOK CRCERR - FNUM10 FNUM9 FNUM8 Table 7-14. 24 Other SFR’s Mnemonic Add Name 7 6 5 4 3 2 1 0 PCON 87h Power Control SMOD1 SMOD0 - POF GF1 GF0 PD IDL AUXR 8Eh Auxiliary Register 0 DPU - M0 - XRS1 XRS2 EXTRAM A0 AUXR1 A2h Auxiliary Register 1 - - ENBOOT - GF3 - - DPS CKCON0 8Fh Clock Control 0 TWIX2 WDX2 PCAX2 SIX2 T2X2 T1X2 T0X2 X2 CKCON1 AFh Clock Control 1 - - - - - - - SPIX2 LEDCON F1h LED Control LED3 LED2 LED1 LED0 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 8. Program/Code Memory The AT83C5134/35/36 implement 16 or 32 Kbytes of on-chip program/code memory. Figure 8-1 shows the split of internal and external program/code memory spaces depending on the product. Figure 8-1. Program/Code Memory Organization FFFFh FFFFh 32 Kbytes External Code 48 Kbytes External Code 8000h 7FFFh 4000h 3FFFh 32 Kbytes ROM 16 Kbytes ROM 0000h 0000h AT83C5135 Note: 8.1 8.1.1 AT83C5136 If the program executes exclusively from on-chip code memory (not from external memory), beware of executing code from the upper byte of on-chip memory and thereby disrupting I/O Ports 0 and 2 due to external prefetch. Fetching code constant from this location does not affect Ports 0 and 2. External Code Memory Access Memory Interface The external memory interface comprises the external bus (Port 0 and Port 2) as well as the bus control signals (PSEN, and ALE). Figure 8-2 shows the structure of the external address bus. P0 carries address A7:0 while P2 carries address A15:8. Data D7:0 is multiplexed with A7:0 on P0. Table 8-1 describes the external memory interface signals. Figure 8-2. External Code Memory Interface Structure Flash EPROM AT89C5131 A15:8 P2 A15:8 ALE P0 AD7:0 Latch A7:0 A7:0 D7:0 PSEN OE 25 7683C–USB–11/07 Table 8-1. 8.1.2 External Data Memory Interface Signals Signal Name Type Alternate Function A15:8 O Address Lines Upper address lines for the external bus. P2.7:0 AD7:0 I/O Address/Data Lines Multiplexed lower address lines and data for the external memory. P0.7:0 ALE O Address Latch Enable ALE signals indicates that valid address information are available on lines AD7:0. - PSEN O Program Store Enable Output This signal is active low during external code fetch or external code read (MOVC instruction). - Description External Bus Cycles This section describes the bus cycles the AT83C5134/35/36 executes to fetch code (see Figure 8-3) in the external program/code memory. External memory cycle takes 6 CPU clock periods. This is equivalent to 12 oscillator clock periods in standard mode or 6 oscillator clock periods in X2 mode. For further information on X2 mode (see the clock Section). For simplicity, the accompanying figure depicts the bus cycle waveforms in idealized form and do not provide precise timing information. Figure 8-3. External Code Fetch Waveforms CPU Clock ALE PSEN P0 D7:0 P2 PCH 26 PCL D7:0 PCH PCL D7:0 PCH AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 9. AT89C5131 ROM 9.1 ROM Structure The AT89C5131 ROM memory is divided in two different arrays: • the code array: 16-32 Kbytes. • the configuration byte:1 byte. 9.1.1 Hardware Configuration Byte The configuration byte sets the starting microcontroller options and the security levels. The starting default options are X1 mode, Oscillator A. Table 9-1. Hardware Security Byte (HSB) HSB (S:EFh) Power configuration Register 7 6 5 4 3 2 1 0 - - OSCON1 OSCON0 - - LB1 LB0 Bit Bit Number Mnemonic 7 - Reserved 6 - Reserved Description Oscillator Control Bits These two bits are used to control the oscillator in order to reduce consumption. OSCON1 OSCON0 Description 1 1 The oscillator is configured to run from 0 to 32 MHz 1 0 The oscillator is configured to run from 0 to 16 MHz 0 1 The oscillator is configured to run from 0 to 8 MHz 0 0 This configuration shouldn’t be set 5-4 OSCON1-0 3 - Reserved 2 - Reserved 1-0 LB1-0 User Program Lock Bits See Table 9-2 on page 28 HSB = xxxx xx11b 9.2 ROM Lock System The program Lock system, when programmed, protects the on-chip program against software piracy. 27 7683C–USB–11/07 9.2.1 Program ROM lock Bits The lock bits when programmed according to Table 9-2 will provide different level of protection for the on-chip code and data. Table 9-2. Program Lock bits Program Lock Bits Protection Description Security level LB1 LB0 1 U U No program lock feature enabled. 3 P U Reading ROM data from programmer is disabled. U: unprogrammed P: programmed 28 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 10. Stacked EEPROM 10.1 Overview The AT83C5134/35/36 features a stacked 2-wire serial data EEPROM. The data EEPROM allows to save from 512 Byte for AT24C04 version up to 32 Kbytes for AT24C256 version. The EEPROM is internally connected to the microcontroller on SDA and SCL pins. 10.2 Protocol In order to access this memory, it is necessary to use software subroutines according to the AT 24Cx x da tashee t. Never thele ss , beca use the in te rnal pul l-u p re sis tors of the AT83C5134/35/36 is quite high (around 100KΩ), the protocol should be slowed in order to be sure that the SDA pin can rise to the high level before reading it. Another solution to keep the access to the EEPROM in specification is to work with a software pull-up. Using a software pull-up, consists of forcing a low level at the output pin of the microcontroller before configuring it as an input (high level). The C51 the ports are “quasi-bidirectional” ports. It means that the ports can be configured as output low or as input high. In case a port is configured as an output low, it can sink a current and all internal pull-ups are disconnected. In case a port is configured as an input high, it is pulled up with a strong pull-up (a few hundreds Ohms resistor) for 2 clock periods. Then, if the port is externally connected to a low level, it is only kept high with a weak pull up (around 100KΩ), and if not, the high level is latched high thanks to a medium pull (around 10kΩ). Thus, when the port is configured as an input, and when this input has been read at a low level, there is a pull-up of around 100KΩ, which is quite high, to quickly load the SDA capacitance. So in order to help the reading of a high level just after the reading of a low level, it is possible to force a transition of the SDA port from an input state (1), to an output low state (0), followed by a new transition from this output low state to input state; In this case, the high pull-up has been replaced with a low pull-up which warranties a good reading of the data. 29 7683C–USB–11/07 11. On-chip Expanded RAM (ERAM) The AT83C5134/35/36 provides additional Bytes of random access memory (RAM) space for increased data parameters handling and high level language usage. AT83C5134/35/36 devices have an expanded RAM in the external data space; maximum size and location are described in Table 11-1. Table 11-1. Description of Expanded RAM Address Part Number ERAM Size Start End AT83C5134/35/36 1024 00h 3FFh The AT83C5134/35/36 has on-chip data memory which is mapped into the following four separate segments. 1. The Lower 128 bytes of RAM (addresses 00h to 7Fh) are directly and indirectly addressable. 2. The Upper 128 bytes of RAM (addresses 80h to FFh) are indirectly addressable only. 3. The Special Function Registers, SFRs, (addresses 80h to FFh) are directly addressable only. 4. The expanded RAM bytes are indirectly accessed by MOVX instructions, and with the EXTRAM bit cleared in the AUXR register (see Table 11-1) The lower 128 bytes can be accessed by either direct or indirect addressing. The Upper 128 bytes can be accessed by indirect addressing only. The Upper 128 bytes occupy the same address space as the SFR. That means they have the same address, but are physically separate from SFR space. Figure 11-1. Internal and External Data Memory Address 0FFh or 3FFh(*) 0FFh 0FFh Upper 128 bytes Internal RAM indirect accesses ERAM 80h 0FFFFh Special Function Register direct accesses External Data Memory 80h 7Fh Lower 128 bytes Internal RAM direct or indirect accesses 00 00 00FFh up to 03FFh (*) 0000 (*) Depends on XRS1..0 When an instruction accesses an internal location above address 7Fh, the CPU knows whether the access is to the upper 128 bytes of data RAM or to SFR space by the addressing mode used in the instruction. 30 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 • Instructions that use direct addressing access SFR space. For example: MOV 0A0H, # data, accesses the SFR at location 0A0h (which is P2). • Instructions that use indirect addressing access the Upper 128 bytes of data RAM. For example: MOV atR0, # data where R0 contains 0A0h, accesses the data byte at address 0A0h, rather than P2 (whose address is 0A0h). • The ERAM bytes can be accessed by indirect addressing, with EXTRAM bit cleared and MOVX instructions. This part of memory which is physically located on-chip, logically occupies the first bytes of external data memory. The bits XRS0 and XRS1 are used to hide a part of the available ERAM as explained in Table 11-1. This can be useful if external peripherals are mapped at addresses already used by the internal ERAM. • With EXTRAM = 0, the ERAM is indirectly addressed, using the MOVX instruction in combination with any of the registers R0, R1 of the selected bank or DPTR. An access to ERAM will not affect ports P0, P2, P3.6 (WR) and P3.7 (RD). For example, with EXTRAM = 0, MOVX atR0, # data where R0 contains 0A0H, accesses the ERAM at address 0A0H rather than external memory. An access to external data memory locations higher than the accessible size of the ERAM will be performed with the MOVX DPTR instructions in the same way as in the standard 80C51, with P0 and P2 as data/address busses, and P3.6 and P3.7 as write and read timing signals. Accesses to ERAM above 0FFH can only be done by the use of DPTR. • With EXTRAM = 1, MOVX @Ri and MOVX @DPTR will be similar to the standard 80C51. MOVX at Ri will provide an eight-bit address multiplexed with data on Port0 and any output port pins can be used to output higher order address bits. This is to provide the external paging capability. MOVX @DPTR will generate a sixteen-bit address. Port2 outputs the highorder eight address bits (the contents of DPH) while Port0 multiplexes the low-order eight address bits (DPL) with data. MOVX at Ri and MOVX @DPTR will generate either read or write signals on P3.6 (WR) and P3.7 (RD). The stack pointer (SP) may be located anywhere in the 256 bytes RAM (lower and upper RAM) internal data memory. The stack may not be located in the ERAM. The M0 bit allows to stretch the ERAM timings; if M0 is set, the read and write pulses are extended from 6 to 30 clock periods. This is useful to access external slow peripherals. Table 11-2. AUXR Register AUXR - Auxiliary Register (8Eh) 7 6 5 4 3 2 1 0 DPU - M0 - XRS1 XRS0 EXTRAM AO Bit Bit Number Mnemonic 7 DPU 6 - Description Disable Weak Pull Up Cleared to enabled weak pull up on standard Ports. Set to disable weak pull up on standard Ports. Reserved The value read from this bit is indeterminate. Do not set this bit Pulse length 5 M0 Cleared to stretch MOVX control: the RD and the WR pulse length is 6 clock periods (default). Set to stretch MOVX control: the RD and the WR pulse length is 30 clock periods. 31 7683C–USB–11/07 Bit Bit Number Mnemonic 4 - 3 XRS1 2 1 XRS0 EXTRAM Description Reserved The value read from this bit is indeterminate. Do not set this bit ERAM Size XRS1XRS0 0 0 ERAM size 256 bytes 0 1 512 bytes 1 0 768 bytes 1 1 1024 bytes (default) EXTRAM bit Cleared to access internal ERAM using MOVX at Ri at DPTR. Set to access external memory. 0 AO ALE Output bit Cleared, ALE is emitted at a constant rate of 1/6 the oscillator frequency (or 1/3 if X2 mode is used) (default). Set, ALE is active only when a MOVX or MOVC instruction is used. Reset Value = 0X0X 1100b Not bit addressable 32 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 12. Timer 2 The Timer 2 in the AT83C5134/35/36 is the standard C52 Timer 2. It is a 16-bit timer/counter: the count is maintained by two cascaded eight-bit timer registers, TH2 and TL2. It is controlled by T2CON (Table 12-1) and T2MOD (Table 12-2) registers. Timer 2 operation is similar to Timer 0 and Timer 1. C/T2 selects FOSC/12 (timer operation) or external pin T2 (counter operation) as the timer clock input. Setting TR2 allows TL2 to be incremented by the selected input. Timer 2 has 3 operating modes: capture, auto reload and Baud Rate Generator. These modes are selected by the combination of RCLK, TCLK and CP/RL2 (T2CON). Refer to the Atmel 8-bit microcontroller hardware documentation for the description of Capture and Baud Rate Generator Modes. Timer 2 includes the following enhancements: • Auto-reload mode with up or down counter • Programmable Clock-output 12.1 Auto-reload Mode The Auto-reload mode configures Timer 2 as a 16-bit timer or event counter with automatic reload. If DCEN bit in T2MOD is cleared, Timer 2 behaves as in 80C52 (refer to the Atmel 8-bit microcontroller hardware description). If DCEN bit is set, Timer 2 acts as an Up/down timer/counter as shown in Figure 12-1. In this mode the T2EX pin controls the direction of count. When T2EX is high, Timer 2 counts up. Timer overflow occurs at FFFFh which sets the TF2 flag and generates an interrupt request. The overflow also causes the 16-bit value in RCAP2H and RCAP2L registers to be loaded into the timer registers TH2 and TL2. When T2EX is low, Timer 2 counts down. Timer underflow occurs when the count in the timer registers TH2 and TL2 equals the value stored in RCAP2H and RCAP2L registers. The underflow sets TF2 flag and reloads FFFFh into the timer registers. The EXF2 bit toggles when Timer 2 overflows or underflows according to the direction of the count. EXF2 does not generate any interrupt. This bit can be used to provide 17-bit resolution. 33 7683C–USB–11/07 Figure 12-1. Auto-reload Mode Up/Down Counter (DCEN = 1) FCLK PERIPH :6 0 1 T2 C/T2 TR2 T2CON T2CON (DOWN COUNTING RELOAD VALUE) T2EX: FFh (8-bit) FFh (8-bit) if DCEN = 1, 1 = UP if DCEN = 1, 0 = DOWN if DCEN = 0, up counting TOGGLE T2CON EXF2 TL2 (8-bit) TH2 (8-bit) TF2 T2CON RCAP2L (8-bit) Timer 2 INTERRUPT RCAP2H (8-bit) (UP COUNTING RELOAD VALUE) 12.2 Programmable Clock Output In the Clock-out mode, Timer 2 operates as a 50%-duty-cycle, programmable clock generator (See Figure 12-2). The input clock increments TL2 at frequency FCLK PERIPH/2. The timer repeatedly counts to overflow from a loaded value. At overflow, the contents of RCAP2H and RCAP2L registers are loaded into TH2 and TL2. In this mode, Timer 2 overflows do not generate interrupts. The following formula gives the Clock-out frequency as a function of the system oscillator frequency and the value in the RCAP2H and RCAP2L registers F CLKPERIPH Clock – OutFrequency = ---------------------------------------------------------------------------------------4 × ( 65536 – RCAP2H ⁄ RCAP2L ) For a 16 MHz system clock, Timer 2 has a programmable frequency range of 61 Hz (FCLK PERIPH/216) to 4 MHz (FCLK PERIPH/4). The generated clock signal is brought out to T2 pin (P1.0). Timer 2 is programmed for the Clock-out mode as follows: • Set T2OE bit in T2MOD register. • Clear C/T2 bit in T2CON register. • Determine the 16-bit reload value from the formula and enter it in RCAP2H/RCAP2L registers. • Enter a 16-bit initial value in timer registers TH2/TL2. It can be the same as the reload value or a different one depending on the application. • To start the timer, set TR2 run control bit in T2CON register. 34 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 It is possible to use Timer 2 as a baud rate generator and a clock generator simultaneously. For this configuration, the baud rates and clock frequencies are not independent since both functions use the values in the RCAP2H and RCAP2L registers. Figure 12-2. Clock-out Mode C/T2 = 0 FCLK PERIPH :6 TR2 T2CON TL2 (8-bit) TH2 (8-bit) OVERFLOW RCAP2L (8-bit) RCAP2H (8-bit) Toggle T2 Q D T2OE T2MOD T2EX EXF2 EXEN2 T2CON Timer 2 INTERRUPT T2CON 35 7683C–USB–11/07 Table 12-1. T2CON Register T2CON - Timer 2 Control Register (C8h) 7 6 5 4 3 2 1 0 TF2 EXF2 RCLK TCLK EXEN2 TR2 C/T2# CP/RL2# Bit Bit Number Mnemonic 7 TF2 Description Timer 2 overflow Flag Must be cleared by software. Set by hardware on Timer 2 overflow, if RCLK = 0 and TCLK = 0. 6 EXF2 Timer 2 External Flag Set when a capture or a reload is caused by a negative transition on T2EX pin if EXEN2 = 1. When set, causes the CPU to vector to Timer 2 interrupt routine when Timer 2 interrupt is enabled. Must be cleared by software. EXF2 doesn’t cause an interrupt in Up/down counter mode (DCEN = 1). 5 RCLK Receive Clock bit Cleared to use Timer 1 overflow as receive clock for serial port in mode 1 or 3. Set to use Timer 2 overflow as receive clock for serial port in mode 1 or 3. 4 TCLK Transmit Clock bit Cleared to use Timer 1 overflow as transmit clock for serial port in mode 1 or 3. Set to use Timer 2 overflow as transmit clock for serial port in mode 1 or 3. 3 EXEN2 2 TR2 1 0 Timer 2 External Enable bit Cleared to ignore events on T2EX pin for Timer 2 operation. Set to cause a capture or reload when a negative transition on T2EX pin is detected, if Timer 2 is not used to clock the serial port. Timer 2 Run control bit Cleared to turn off Timer 2. Set to turn on Timer 2. C/T2# Timer/Counter 2 select bit Cleared for timer operation (input from internal clock system: FCLK PERIPH). Set for counter operation (input from T2 input pin, falling edge trigger). Must be 0 for clock out mode. CP/RL2# Timer 2 Capture/Reload bit If RCLK = 1 or TCLK = 1, CP/RL2# is ignored and timer is forced to Auto-reload on Timer 2 overflow. Cleared to Auto-reload on Timer 2 overflows or negative transitions on T2EX pin if EXEN2 = 1. Set to capture on negative transitions on T2EX pin if EXEN2 = 1. Reset Value = 0000 0000b Bit addressable 36 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 Table 12-2. T2MOD Register T2MOD - Timer 2 Mode Control Register (C9h) 7 6 5 4 3 2 1 0 - - - - - - T2OE DCEN Bit Bit Number Mnemonic 7 - Reserved The value read from this bit is indeterminate. Do not set this bit. 6 - Reserved The value read from this bit is indeterminate. Do not set this bit. 5 - Reserved The value read from this bit is indeterminate. Do not set this bit. 4 - Reserved The value read from this bit is indeterminate. Do not set this bit. 3 - Reserved The value read from this bit is indeterminate. Do not set this bit. 2 - Reserved The value read from this bit is indeterminate. Do not set this bit. 1 T2OE Timer 2 Output Enable bit Cleared to program P1.0/T2 as clock input or I/O port. Set to program P1.0/T2 as clock output. 0 DCEN Down Counter Enable bit Cleared to disable Timer 2 as up/down counter. Set to enable Timer 2 as up/down counter. Description Reset Value = xxxx xx00b Not bit addressable 37 7683C–USB–11/07 13. Programmable Counter Array (PCA) The PCA provides more timing capabilities with less CPU intervention than the standard timer/counters. Its advantages include reduced software overhead and improved accuracy. The PCA consists of a dedicated timer/counter which serves as the time base for an array of five compare/capture modules. Its clock input can be programmed to count any one of the following signals: ÷6 • Peripheral clock frequency (FCLK PERIPH) ÷ 2 • Peripheral clock frequency (FCLK PERIPH) • Timer 0 overflow • External input on ECI (P1.2) Each compare/capture modules can be programmed in any one of the following modes: • rising and/or falling edge capture, • software timer • high-speed output, or • pulse width modulator Module 4 can also be programmed as a watchdog timer (see Section "PCA Watchdog Timer", page 48). When the compare/capture modules are programmed in the capture mode, software timer, or high speed output mode, an interrupt can be generated when the module executes its function. All five modules plus the PCA timer overflow share one interrupt vector. The PCA timer/counter and compare/capture modules share Port 1 for external I/O. These pins are listed below. If the port pin is not used for the PCA, it can still be used for standard I/O. PCA Component External I/O Pin 16-bit Counter P1.2/ECI 16-bit Module 0 P1.3/CEX0 16-bit Module 1 P1.4/CEX1 16-bit Module 2 P1.5/CEX2 16-bit Module 3 P1.6/CEX3 16-bit Module 4 P1.7/CEX4 The PCA timer is a common time base for all five modules (see Figure 13-1). The timer count source is determined from the CPS1 and CPS0 bits in the CMOD register (Table 13-1) and can be programmed to run at: • 1/6 the peripheral clock frequency (FCLK PERIPH). • 1/2 the peripheral clock frequency (FCLK PERIPH). • The Timer 0 overflow • The input on the ECI pin (P1.2) 38 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 Figure 13-1. PCA Timer/Counter To PCA modules FCLK PERIPH/6 overflow FCLK PERIPH/2 CH T0 OVF It CL 16 Bit Up Counter P1.2 CIDL WDTE CF CR CPS1 CPS0 ECF CMOD 0xD9 CCF2 CCF1 CCF0 CCON 0xD8 Idle Table 13-1. CCF4 CCF3 CMOD Register CMOD - PCA Counter Mode Register (D9h) 7 6 5 4 3 2 1 0 CIDL WDTE - - - CPS1 CPS0 ECF Bit Bit Number Mnemonic 7 CIDL Description Counter Idle Control Cleared to program the PCA Counter to continue functioning during idle Mode. Set to program PCA to be gated off during idle. Watchdog Timer Enable 6 WDTE Cleared to disable Watchdog Timer function on PCA Module 4. Set to enable Watchdog Timer function on PCA Module 4. 5 - Reserved The value read from this bit is indeterminate. Do not set this bit. 4 - Reserved The value read from this bit is indeterminate. Do not set this bit. 3 - Reserved The value read from this bit is indeterminate. Do not set this bit. 2 CPS1 1 CPS0 0 ECF PCA Count Pulse Select CPS1CPS0 0 0 Selected PCA input Internal clock fCLK PERIPH/6 0 1 1 Internal clock fCLK PERIPH/2 Timer 0 Overflow External clock at ECI/P1.2 pin (max rate = fCLK PERIPH/ 4) 1 0 1 PCA Enable Counter Overflow Interrupt Cleared to disable CF bit in CCON to inhibit an interrupt. Set to enable CF bit in CCON to generate an interrupt. 39 7683C–USB–11/07 Reset Value = 00XX X000b Not bit addressable The CMOD register includes three additional bits associated with the PCA (See Figure 13-1 and Table 13-1). • The CIDL bit allows the PCA to stop during idle mode. • The WDTE bit enables or disables the watchdog function on module 4. • The ECF bit when set causes an interrupt and the PCA overflow flag CF (in the CCON SFR) to be set when the PCA timer overflows. The CCON register contains the run control bit for the PCA and the flags for the PCA timer (CF) and each module (see Table 13-2). • Bit CR (CCON.6) must be set by software to run the PCA. The PCA is shut off by clearing this bit. • Bit CF: The CF bit (CCON.7) is set when the PCA counter overflows and an interrupt will be generated if the ECF bit in the CMOD register is set. The CF bit can only be cleared by software. • Bits 0 through 4 are the flags for the modules (bit 0 for module 0, bit 1 for module 1, etc.) and are set by hardware when either a match or a capture occurs. These flags can only be cleared by software. Table 13-2. CCON Register CCON - PCA Counter Control Register (D8h) 7 6 5 4 3 2 1 0 CF CR – CCF4 CCF3 CCF2 CCF1 CCF0 Bit Bit Number Mnemonic 7 CF 6 CR 5 – 4 CCF4 3 CCF3 2 CCF2 Description PCA Counter Overflow flag Set by hardware when the counter rolls over. CF flags an interrupt if bit ECF in CMOD is set. CF may be set by either hardware or software but can only be cleared by software. PCA Counter Run control bit Must be cleared by software to turn the PCA counter off. Set by software to turn the PCA counter on. Reserved The value read from this bit is indeterminate. Do not set this bit. PCA Module 4 interrupt flag Must be cleared by software. Set by hardware when a match or capture occurs. PCA Module 3 interrupt flag Must be cleared by software. Set by hardware when a match or capture occurs. PCA Module 2 interrupt flag 40 Must be cleared by software. Set by hardware when a match or capture occurs. AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 Bit Bit Number Mnemonic 1 CCF1 0 CCF0 Description PCA Module 1 Interrupt Flag Must be cleared by software. Set by hardware when a match or capture occurs. PCA Module 0 Interrupt Flag Must be cleared by software. Set by hardware when a match or capture occurs. Reset Value = 000X 0000b Not bit addressable The watchdog timer function is implemented in module 4 (See Figure 13-4). The PCA interrupt system is shown in Figure 13-2. Figure 13-2. PCA Interrupt System CF CR CCF4 CCF3 CCF2 CCF1 CCF0 CCON 0xD8 PCA Timer/Counter Module 0 Module 1 To Interrupt priority decoder Module 2 Module 3 Module 4 CMOD.0 ECF ECCFn CCAPMn.0 IE.6 EC IE.7 EA PCA Modules: each one of the five compare/capture modules has six possible functions. It can perform: • 16-bit capture, positive-edge triggered • 16-bit capture, negative-edge triggered • 16-bit capture, both positive and negative-edge triggered • 16-bit Software Timer • 16-bit High-speed Output • 8-bit Pulse Width Modulator In addition, module 4 can be used as a Watchdog Timer. Each module in the PCA has a special function register associated with it. These registers are: CCAPM0 for module 0, CCAPM1 for module 1, etc. (see Table 13-3). The registers contain the bits that control the mode that each module will operate in. 41 7683C–USB–11/07 • The ECCF bit (CCAPMn.0 where n = 0, 1, 2, 3, or 4 depending on the module) enables the CCF flag in the CCON SFR to generate an interrupt when a match or compare occurs in the associated module. • PWM (CCAPMn.1) enables the pulse width modulation mode. • The TOG bit (CCAPMn.2) when set causes the CEX output associated with the module to toggle when there is a match between the PCA counter and the module's capture/compare register. • The match bit MAT (CCAPMn.3) when set will cause the CCFn bit in the CCON register to be set when there is a match between the PCA counter and the module's capture/compare register. • The next two bits CAPN (CCAPMn.4) and CAPP (CCAPMn.5) determine the edge that a capture input will be active on. The CAPN bit enables the negative edge, and the CAPP bit enables the positive edge. If both bits are set both edges will be enabled and a capture will occur for either transition. • The last bit in the register ECOM (CCAPMn.6) when set enables the comparator function. Table 13-4 shows the CCAPMn settings for the various PCA functions. Table 13-3. CCAPMn Registers (n = 0-4) CCAPM0 - PCA Module 0 Compare/Capture Control Register (0DAh) CCAPM1 - PCA Module 1 Compare/Capture Control Register (0DBh) CCAPM2 - PCA Module 2 Compare/Capture Control Register (0DCh) CCAPM3 - PCA Module 3 Compare/Capture Control Register (0DDh) CCAPM4 - PCA Module 4 Compare/Capture Control Register (0DEh) 7 6 5 4 3 2 1 0 - ECOMn CAPPn CAPNn MATn TOGn PWMn ECCFn Bit Bit Number Mnemonic 7 - 6 ECOMn Description Reserved The value read from this bit is indeterminate. Do not set this bit. Enable Comparator Cleared to disable the comparator function. Set to enable the comparator function. Capture Positive 5 CAPPn 4 CAPNn Cleared to disable positive edge capture. Set to enable positive edge capture. Capture Negative Cleared to disable negative edge capture. Set to enable negative edge capture. Match 3 MATn When MATn = 1, a match of the PCA counter with this module's compare/capture register causes the CCFn bit in CCON to be set, flagging an interrupt. Toggle 2 42 TOGn When TOGn = 1, a match of the PCA counter with this module's compare/capture register causes the CEXn pin to toggle. AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 Bit Bit Number Mnemonic 1 PWMn Description Pulse Width Modulation Mode Cleared to disable the CEXn pin to be used as a pulse width modulated output. Set to enable the CEXn pin to be used as a pulse width modulated output. Enable CCF Interrupt 0 ECCFn Cleared to disable compare/capture flag CCFn in the CCON register to generate an interrupt. Set to enable compare/capture flag CCFn in the CCON register to generate an interrupt. Reset Value = X000 0000b Not bit addressable Table 13-4. PCA Module Modes (CCAPMn Registers) ECOMn CAPPn CAPNn MATn TOGn PWMm ECCFn Module Function 0 0 0 0 0 0 0 No Operation X 1 0 0 0 0 X 16-bit capture by a positive-edge trigger on CEXn X 0 1 0 0 0 X 16-bit capture by a negative trigger on CEXn X 1 1 0 0 0 X 16-bit capture by a transition on CEXn 1 0 0 1 0 0 X 16-bit Software Timer/Compare mode. 1 0 0 1 1 0 X 16-bit High Speed Output 1 0 0 0 0 1 0 8-bit PWM 1 0 0 1 X 0 X Watchdog Timer (module 4 only) There are two additional registers associated with each of the PCA modules. They are CCAPnH and CCAPnL and these are the registers that store the 16-bit count when a capture occurs or a compare should occur. When a module is used in the PWM mode these registers are used to control the duty cycle of the output (see Table 13-5 and Table 13-6) 43 7683C–USB–11/07 Table 13-5. CCAPnH Registers (n = 0-4) CCAP0H - PCA Module 0 Compare/Capture Control Register High (0FAh) CCAP1H - PCA Module 1 Compare/Capture Control Register High (0FBh) CCAP2H - PCA Module 2 Compare/Capture Control Register High (0FCh) CCAP3H - PCA Module 3 Compare/Capture Control Register High (0FDh) CCAP4H - PCA Module 4 Compare/Capture Control Register High (0FEh) 7 6 5 4 3 2 1 0 - - - - - - - - Bit Bit Number Mnemonic 7-0 - Description PCA Module n Compare/Capture Control CCAPnH Value Reset Value = XXXX XXXXb Not bit addressable Table 13-6. CCAPnL Registers (n = 0-4) CCAP0L - PCA Module 0 Compare/Capture Control Register Low (0EAh) CCAP1L - PCA Module 1 Compare/Capture Control Register Low (0EBh) CCAP2L - PCA Module 2 Compare/Capture Control Register Low (0ECh) CCAP3L - PCA Module 3 Compare/Capture Control Register Low (0EDh) CCAP4L - PCA Module 4 Compare/Capture Control Register Low (0EEh) 7 6 5 4 3 2 1 0 - - - - - - - - Bit Bit Number Mnemonic 7-0 - Description PCA Module n Compare/Capture Control CCAPnL Value Reset Value = XXXX XXXXb Not bit addressable Table 13-7. CH Register CH - PCA Counter Register High (0F9h) 7 6 5 4 3 2 1 0 - - - - - - - - Bit Bit Number Mnemonic Description 7-0 - PCA counter CH Value Reset Value = 0000 0000b Not bit addressable 44 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 Table 13-8. CL Register CL - PCA Counter Register Low (0E9h) 7 6 5 4 3 2 1 0 - - - - - - - - Bit Bit Number Mnemonic 7-0 - Description PCA Counter CL Value Reset Value = 0000 0000b Not bit addressable 13.1 PCA Capture Mode To use one of the PCA modules in the capture mode either one or both of the CCAPM bits CAPN and CAPP for that module must be set. The external CEX input for the module (on port 1) is sampled for a transition. When a valid transition occurs the PCA hardware loads the value of the PCA counter registers (CH and CL) into the module's capture registers (CCAPnL and CCAPnH). If the CCFn bit for the module in the CCON SFR and the ECCFn bit in the CCAPMn SFR are set then an interrupt will be generated (see Figure 13-3). Figure 13-3. PCA Capture Mode CF CR CCF4 CCF3 CCF2 CCF1 CCF0 CCON 0xD8 PCA IT PCA Counter/Timer Cex.n CH CL CCAPnH CCAPnL Capture ECOMn CAPPn CAPNn MATn TOGn PWMn ECCFn CCAPMn, n = 0 to 4 0xDA to 0xDE 13.2 16-bit Software Timer/Compare Mode The PCA modules can be used as software timers by setting both the ECOM and MAT bits in the modules CCAPMn register. The PCA timer will be compared to the module's capture registers and when a match occurs an interrupt will occur if the CCFn (CCON SFR) and the ECCFn (CCAPMn SFR) bits for the module are both set (see Figure 13-4). 45 7683C–USB–11/07 Figure 13-4. PCA Compare Mode and PCA Watchdog Timer CCON CF Write to CCAPnL CR CCF4 CCF3 CCF2 CCF1 CCF0 0xD8 Reset PCA IT Write to CCAPnH 1 CCAPnH 0 CCAPnL Enable Match 16-bit Comparator CH RESET(1) CL PCA Counter/Timer ECOMn CAPPn CAPNn MATn TOGn PWMn ECCFn CIDL Note: WDTE CPS1 CPS0 ECF CCAPMn, n = 0 to 4 0xDA to 0xDE CMOD 0xD9 1. Only for Module 4 Before enabling ECOM bit, CCAPnL and CCAPnH should be set with a non zero value, otherwise an unwanted match could happen. Writing to CCAPnH will set the ECOM bit. Once ECOM set, writing CCAPnL will clear ECOM so that an unwanted match doesn’t occur while modifying the compare value. Writing to CCAPnH will set ECOM. For this reason, user software should write CCAPnL first, and then CCAPnH. Of course, the ECOM bit can still be controlled by accessing to CCAPMn register. 13.3 High Speed Output Mode In this mode, the CEX output (on port 1) associated with the PCA module will toggle each time a match occurs between the PCA counter and the module's capture registers. To activate this mode the TOG, MAT, and ECOM bits in the module's CCAPMn SFR must be set (see Figure 13-5). A prior write must be done to CCAPnL and CCAPnH before writing the ECOMn bit. 46 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 Figure 13-5. PCA High-speed Output Mode CCON CF CR CCF4 CCF3 CCF2 CCF1 CCF0 0xD8 Write to CCAPnL Reset PCA IT Write to CCAPnH 1 CCAPnH 0 CCAPnL Enable 16-bit Comparator CH Match CL CEXn PCA counter/timer ECOMn CAPPn CAPNn MATn TOGn PWMn ECCFn CCAPMn, n = 0 to 4 0xDA to 0xDE Before enabling ECOM bit, CCAPnL and CCAPnH should be set with a non zero value, otherwise an unwanted match could happen. Once ECOM set, writing CCAPnL will clear ECOM so that an unwanted match doesn’t occur while modifying the compare value. Writing to CCAPnH will set ECOM. For this reason, user software should write CCAPnL first, and then CCAPnH. Of course, the ECOM bit can still be controlled by accessing to CCAPMn register. 13.4 Pulse Width Modulator Mode All of the PCA modules can be used as PWM outputs. Figure 13-6 shows the PWM function. The frequency of the output depends on the source for the PCA timer. All of the modules will have the same frequency of output because they all share the PCA timer. The duty cycle of each module is independently variable using the module's capture register CCAPLn. When the value of the PCA CL SFR is less than the value in the module's CCAPLn SFR the output will be low, when it is equal to or greater than the output will be high. When CL overflows from FF to 00, CCAPLn is reloaded with the value in CCAPHn. This allows updating the PWM without glitches. The PWM and ECOM bits in the module's CCAPMn register must be set to enable the PWM mode. 47 7683C–USB–11/07 Figure 13-6. PCA PWM Mode CCAPnH Overflow CCAPnL “0” Enable 8-bit Comparator CEXn < ≥ “1” CL PCA Counter/Timer ECOMn CAPPn CAPNn MATn TOGn PWMn ECCFn CCAPMn, n = 0 to 4 0xDA to 0xDE 13.5 PCA Watchdog Timer An on-board watchdog timer is available with the PCA to improve the reliability of the system without increasing chip count. Watchdog timers are useful for systems that are susceptible to noise, power glitches, or electrostatic discharge. Module 4 is the only PCA module that can be programmed as a watchdog. However, this module can still be used for other modes if the watchdog is not needed. Figure 13-4 shows a diagram of how the watchdog works. The user pre-loads a 16-bit value in the compare registers. Just like the other compare modes, this 16-bit value is compared to the PCA timer value. If a match is allowed to occur, an internal reset will be generated. This will not cause the RST pin to be driven low. In order to hold off the reset, the user has three options: 1. Periodically change the compare value so it will never match the PCA timer 2. Periodically change the PCA timer value so it will never match the compare values, or 3. Disable the watchdog by clearing the WDTE bit before a match occurs and then reenable it The first two options are more reliable because the watchdog timer is never disabled as in option #3. If the program counter ever goes astray, a match will eventually occur and cause an internal reset. The second option is also not recommended if other PCA modules are being used. Remember, the PCA timer is the time base for all modules; changing the time base for other modules would not be a good idea. Thus, in most applications the first solution is the best option. This watchdog timer won’t generate a reset out on the reset pin. 48 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 14. Serial I/O Port The serial I/O port in the AT83C5134/35/36 is compatible with the serial I/O port in the 80C52. It provides both synchronous and asynchronous communication modes. It operates as an Universal Asynchronous Receiver and Transmitter (UART) in three full-duplex modes (modes 1, 2 and 3). Asynchronous transmission and reception can occur simultaneously and at different baud rates. Serial I/O port includes the following enhancements: • Framing error detection • Automatic address recognition 14.1 Framing Error Detection Framing bit error detection is provided for the three asynchronous modes (modes 1, 2 and 3). To enable the framing bit error detection feature, set SMOD0 bit in PCON register (see Figure 141). Figure 14-1. Framing Error Block Diagram SM0/FE SM1 SM2 REN TB8 RB8 TI RI SCON (98h) Set FE Bit if Stop Bit is 0 (framing error) (SMOD0 = 1) SM0 to UART Mode Control (SMOD0 = 0) SMOD1 SMOD0 - POF GF1 GF0 PD PCON (87h) IDL To UART Framing Error Control When this feature is enabled, the receiver checks each incoming data frame for a valid stop bit. An invalid stop bit may result from noise on the serial lines or from simultaneous transmission by two CPUs. If a valid stop bit is not found, the Framing Error bit (FE) in SCON register (See Table 14-1) bit is set. Software may examine FE bit after each reception to check for data errors. Once set, only software or a reset can clear FE bit. Subsequently received frames with valid stop bits cannot clear FE bit. When FE feature is enabled, RI rises on stop bit instead of the last data bit (See Figure 14-2 and Figure 14-3). Figure 14-2. UART Timings in Mode 1 RXD D0 Start Bit D1 D2 D3 D4 Data Byte D5 D6 D7 Stop Bit RI SMOD0 = X FE SMOD0 = 1 49 7683C–USB–11/07 Figure 14-3. UART Timings in Modes 2 and 3 RXD D0 Start Bit D1 D2 D3 D4 Data Byte D5 D6 D7 D8 Ninth Stop Bit Bit RI SMOD0 = 0 RI SMOD0 = 1 FE SMOD0 = 1 14.2 Automatic Address Recognition The automatic address recognition feature is enabled when the multiprocessor communication feature is enabled (SM2 bit in SCON register is set). Implemented in hardware, automatic address recognition enhances the multiprocessor communication feature by allowing the serial port to examine the address of each incoming command frame. Only when the serial port recognizes its own address, the receiver sets RI bit in SCON register to generate an interrupt. This ensures that the CPU is not interrupted by command frames addressed to other devices. If desired, you may enable the automatic address recognition feature in mode 1. In this configuration, the stop bit takes the place of the ninth data bit. Bit RI is set only when the received command frame address matches the device’s address and is terminated by a valid stop bit. To support automatic address recognition, a device is identified by a given address and a broadcast address. Note: 14.2.1 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). Given Address Each device has an individual address that is specified in SADDR register; the SADEN register is a mask byte that contains don’t care bits (defined by zeros) to form the device’s given address. The don’t care bits provide the flexibility to address one or more slaves at a time. The following example illustrates how a given address is formed. To address a device by its individual address, the SADEN mask byte must be 1111 1111b. For example: SADDR0101 0110b SADEN1111 1100b Given0101 01XXb The following is an example of how to use given addresses to address different slaves: Slave A:SADDR1111 0001b SADEN1111 1010b Given1111 0X0Xb Slave B:SADDR1111 0011b SADEN1111 1001b Given1111 0XX1b 50 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 Slave C:SADDR1111 0011b SADEN1111 1101b Given1111 00X1b The SADEN byte is selected so that each slave may be addressed separately. For slave A, bit 0 (the LSB) is a don’t care bit; for slaves B and C, bit 0 is a 1. To communicate with slave A only, the master must send an address where bit 0 is clear (e.g. 1111 0000b). For slave A, bit 1 is a 1; for slaves B and C, bit 1 is a don’t care bit. To communicate with slaves B and C, but not slave A, the master must send an address with bits 0 and 1 both set (e.g. 1111 0011b). To communicate with slaves A, B and C, the master must send an address with bit 0 set, bit 1 clear, and bit 2 clear (e.g. 1111 0001b). 14.2.2 Broadcast Address A broadcast address is formed from the logical OR of the SADDR and SADEN registers with zeros defined as don’t care bits, e.g.: SADDR0101 0110b SADEN1111 1100b Broadcast = SADDR OR SADEN1111 111Xb The use of don’t care bits provides flexibility in defining the broadcast address, in most applications, a broadcast address is FFh. The following is an example of using broadcast addresses: Slave A:SADDR1111 0001b SADEN1111 1010b Broadcast1111 1X11b, Slave B:SADDR1111 0011b SADEN1111 1001b Broadcast1111 1X11B, Slave C:SADDR = 1111 0011b SADEN1111 1101b Broadcast1111 1111b For slaves A and B, bit 2 is a don’t care bit; for slave C, bit 2 is set. To communicate with all of the slaves, the master must send an address FFh. To communicate with slaves A and B, but not slave C, the master can send and address FBh. 14.2.3 Reset Addresses On reset, the SADDR and SADEN registers are initialized to 00h, i.e. the given and broadcast addresses are XXXX XXXXb (all don’t care bits). This ensures that the serial port will reply to any address, and so, that it is backwards compatible with the 80C51 microcontrollers that do not support automatic address recognition. 51 7683C–USB–11/07 SADEN - Slave Address Mask Register (B9h) 7 6 5 4 3 2 1 0 4 3 2 1 0 Reset Value = 0000 0000b Not bit addressable SADDR - Slave Address Register (A9h) 7 6 5 Reset Value = 0000 0000b Not bit addressable 14.3 Baud Rate Selection for UART for Mode 1 and 3 The Baud Rate Generator for transmit and receive clocks can be selected separately via the T2CON and BDRCON registers. Figure 14-4. Baud Rate Selection TIMER1 TIMER2 0 TIMER_BRG_RX 0 1 / 16 Rx Clock 1 RCLK RBCK INT_BRG TIMER1 TIMER2 0 1 TIMER_BRG_TX 0 1 / 16 Tx Clock TCLK INT_BRG 52 TBCK AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 14.3.1 14.3.2 Baud Rate Selection Table for UART TCLK RCLK TBCK RBCK Clock Source Clock Source (T2CON) (T2CON) (BDRCON) (BDRCON) UART Tx UART Rx 0 0 0 0 Timer 1 Timer 1 1 0 0 0 Timer 2 Timer 1 0 1 0 0 Timer 1 Timer 2 1 1 0 0 Timer 2 Timer 2 X 0 1 0 INT_BRG Timer 1 X 1 1 0 INT_BRG Timer 2 0 X 0 1 Timer 1 INT_BRG 1 X 0 1 Timer 2 INT_BRG X X 1 1 INT_BRG INT_BRG Internal Baud Rate Generator (BRG) When the internal Baud Rate Generator is used, the Baud Rates are determined by the BRG overflow depending on the BRL reload value, the value of SPD bit (Speed Mode) in BDRCON register and the value of the SMOD1 bit in PCON register. Figure 14-5. Internal Baud Rate Peripheral Clock auto reload counter overflow BRG 0 /6 /2 0 1 INT_BRG 1 BRL SPD SMOD1 BRR • The baud rate for UART is token by formula: 2SMOD1 x FCLK PERIPH Baud_Rate = 2x6 (1-SPD) 2SMOD1 x FCLK PERIPH (BRL) = 256 2x6 Table 14-1. x 16 x [256 - (BRL)] (1-SPD) x 16 x Baud_Rate SCON Register – SCON Serial Control Register (98h) 7 6 5 4 3 2 1 0 FE/SM0 SM1 SM2 REN TB8 RB8 TI RI 53 7683C–USB–11/07 Bit Bit Number Mnemonic FE Description Framing Error bit (SMOD0 = 1) Clear to reset the error state, not cleared by a valid stop bit. Set by hardware when an invalid stop bit is detected. SMOD0 must be set to enable access to the FE bit 7 SM0 Serial port Mode bit 0 Refer to SM1 for serial port mode selection. SMOD0 must be cleared to enable access to the SM0 bit 6 SM1 Serial port Mode bit 1 SM0 SM1 Mode 0 0 0 0 1 1 1 0 2 Description Shift Register 8-bit UART 9-bit UART Baud Rate FCPU PERIPH/6 Variable FCPU PERIPH/32 or/16 1 9-bit UART Variable 1 3 5 SM2 Serial port Mode 2 bit/Multiprocessor Communication Enable bit Clear to disable multiprocessor communication feature. Set to enable multiprocessor communication feature in mode 2 and 3, and eventually mode 1. This bit should be cleared in mode 0. 4 REN Reception Enable bit Clear to disable serial reception. Set to enable serial reception. 3 TB8 Transmitter Bit 8/Ninth bit to Transmit in Modes 2 and 3 2 RB8 Clear to transmit a logic 0 in the 9th bit. Set to transmit a logic 1 in the 9th bit. Receiver Bit 8/Ninth bit received in modes 2 and 3 Cleared by hardware if 9th bit received is a logic 0. Set by hardware if 9th bit received is a logic 1. In mode 1, if SM2 = 0, RB8 is the received stop bit. In mode 0 RB8 is not used. 1 0 TI Transmit Interrupt flag Clear to acknowledge interrupt. Set by hardware at the end of the 8th bit time in mode 0 or at the beginning of the stop bit in the other modes. RI Receive Interrupt flag Clear to acknowledge interrupt. Set by hardware at the end of the 8th bit time in mode 0, see Figure 14-2. and Figure 143. in the other modes. Reset Value = 0000 0000b Bit addressable 54 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 Example of computed value when X2 = 1, SMOD1 = 1, SPD = 1 FOSC = 16.384 MHz Baud Rates FOSC = 24 MHz BRL Error (%) BRL Error (%) 115200 247 1.23 243 0.16 57600 238 1.23 230 0.16 38400 229 1.23 217 0.16 28800 220 1.23 204 0.16 19200 203 0.63 178 0.16 9600 149 0.31 100 0.16 4800 43 1.23 - - Example of computed value when X2 = 0, SMOD1 = 0, SPD = 0 FOSC = 16.384 MHz FOSC = 24 MHz Baud Rates BRL Error (%) BRL Error (%) 4800 247 1.23 243 0.16 2400 238 1.23 230 0.16 1200 220 1.23 202 3.55 600 185 0.16 152 0.16 The baud rate generator can be used for mode 1 or 3 (refer to Figure 14-4.), but also for mode 0 for UART, thanks to the bit SRC located in BDRCON register (Table 14-4.) 14.4 UART Registers SADEN - Slave Address Mask Register for UART (B9h) 7 6 5 4 3 2 1 0 – – – – – – – – Reset Value = 0000 0000b SADDR - Slave Address Register for UART (A9h) 7 6 5 4 3 2 1 0 – – – – – – – – Reset Value = 0000 0000b SBUF - Serial Buffer Register for UART (99h) 7 6 5 4 3 2 1 0 – – – – – – – – Reset Value = XXXX XXXXb 55 7683C–USB–11/07 BRL - Baud Rate Reload Register for the internal baud rate generator, UART (9Ah) 7 6 5 4 3 2 1 0 – – – – – – – – Reset Value = 0000 0000b Table 14-2. T2CON Register T2CON - Timer 2 Control Register (C8h) 7 6 5 4 3 2 1 0 TF2 EXF2 RCLK TCLK EXEN2 TR2 C/T2# CP/RL2# Bit Bit Number Mnemonic 7 TF2 Description Timer 2 overflow Flag Must be cleared by software. Set by hardware on Timer 2 overflow, if RCLK = 0 and TCLK = 0. 6 EXF2 Timer 2 External Flag Set when a capture or a reload is caused by a negative transition on T2EX pin if EXEN2 = 1. When set, causes the CPU to vector to Timer 2 interrupt routine when Timer 2 interrupt is enabled. Must be cleared by software. EXF2 doesn’t cause an interrupt in Up/down counter mode (DCEN = 1) 5 RCLK Receive Clock bit for UART Cleared to use Timer 1 overflow as receive clock for serial port in mode 1 or 3. Set to use Timer 2 overflow as receive clock for serial port in mode 1 or 3. 4 TCLK Transmit Clock bit for UART Cleared to use Timer 1 overflow as transmit clock for serial port in mode 1 or 3. Set to use Timer 2 overflow as transmit clock for serial port in mode 1 or 3. Timer 2 External Enable bit Cleared to ignore events on T2EX pin for Timer 2 operation. Set to cause a capture or reload when a negative transition on T2EX pin is detected, if Timer 2 is not used to clock the serial port. 3 EXEN2 2 TR2 1 C/T2# Timer/Counter 2 select bit Cleared for timer operation (input from internal clock system: FCLK PERIPH). Set for counter operation (input from T2 input pin, falling edge trigger). Must be 0 for clock out mode. CP/RL2# Timer 2 Capture/Reload bit If RCLK = 1 or TCLK = 1, CP/RL2# is ignored and timer is forced to Auto-reload on Timer 2 overflow. Cleared to Auto-reload on Timer 2 overflows or negative transitions on T2EX pin if EXEN2 = 1. Set to capture on negative transitions on T2EX pin if EXEN2 = 1. 0 Timer 2 Run control bit Cleared to turn off Timer 2. Set to turn on Timer 2. Reset Value = 0000 0000b Bit addressable 56 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 Table 14-3. PCON Register PCON - Power Control Register (87h) 7 6 5 4 3 2 1 0 SMOD1 SMOD0 - POF GF1 GF0 PD IDL Bit Bit Number Mnemonic 7 SMOD1 6 SMOD0 5 - Description Serial port Mode bit 1 for UART Set to select double baud rate in mode 1, 2 or 3. Serial port Mode bit 0 for UART Cleared to select SM0 bit in SCON register. Set to select FE bit in SCON register. Reserved The value read from this bit is indeterminate. Do not set this bit. 4 POF Power-Off Flag Cleared to recognize next reset type. Set by hardware when VCC rises from 0 to its nominal voltage. Can also be set by software. 3 GF1 General-purpose Flag Cleared by user for general-purpose usage. Set by user for general-purpose usage. 2 GF0 General-purpose Flag Cleared by user for general-purpose usage. Set by user for general-purpose usage. 1 PD Power-down Mode Bit Cleared by hardware when reset occurs. Set to enter power-down mode. 0 IDL Idle Mode Bit Cleared by hardware when interrupt or reset occurs. Set to enter idle mode. Reset Value = 00x1 0000b Not bit addressable Power-off flag reset value will be 1 only after a power on (cold reset). A warm reset doesn’t affect the value of this bit. 57 7683C–USB–11/07 Table 14-4. BDRCON Register BDRCON - Baud Rate Control Register (9Bh) 7 6 5 4 3 2 1 0 - - - BRR TBCK RBCK SPD SRC Bit Number Bit Mnemonic 7 - Reserved The value read from this bit is indeterminate. Do not set this bit 6 - Reserved The value read from this bit is indeterminate. Do not set this bit 5 - Reserved The value read from this bit is indeterminate. Do not set this bit. 4 BRR Baud Rate Run Control bit Cleared to stop the internal Baud Rate Generator. Set to start the internal Baud Rate Generator. 3 TBCK Transmission Baud rate Generator Selection bit for UART Cleared to select Timer 1 or Timer 2 for the Baud Rate Generator. Set to select internal Baud Rate Generator. 2 RBCK Reception Baud Rate Generator Selection bit for UART Cleared to select Timer 1 or Timer 2 for the Baud Rate Generator. Set to select internal Baud Rate Generator. 1 SPD 0 SRC Description Baud Rate Speed Control bit for UART Cleared to select the SLOW Baud Rate Generator. Set to select the FAST Baud Rate Generator. Baud Rate Source select bit in Mode 0 for UART Cleared to select FOSC/12 as the Baud Rate Generator (FCLK PERIPH/6 in X2 mode). Set to select the internal Baud Rate Generator for UARTs in mode 0. Reset Value = xxx0 0000b Not bit addressable 58 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 15. Dual Data Pointer Register The additional data pointer can be used to speed up code execution and reduce code size. The dual DPTR structure is a way by which the chip will specify the address of an external data memory location. There are two 16-bit DPTR registers that address the external memory, and a single bit called DPS = AUXR1.0 (see Table 15-1) that allows the program code to switch between them (see Figure 15-1). Figure 15-1. Use of Dual Pointer External Data Memory 7 0 DPS DPTR1 DPTR0 AUXR1(A2H) DPH(83H) DPL(82H) Table 15-1. AUXR1 Register AUXR1- Auxiliary Register 1(0A2h) 7 6 5 4 3 2 1 0 - - - - GF3 0 - DPS Bit Bit Number Mnemonic 7 - Reserved The value read from this bit is indeterminate. Do not set this bit. 6 - Reserved The value read from this bit is indeterminate. Do not set this bit. 5 - Reserved The value read from this bit is indeterminate. Do not set this bit. 4 - Reserved The value read from this bit is indeterminate. Do not set this bit. 3 GF3 2 0 Always cleared. 1 - Reserved The value read from this bit is indeterminate. Do not set this bit. 0 DPS Description This bit is a general-purpose user flag. Data Pointer Selection Cleared to select DPTR0. Set to select DPTR1. Reset Value = xxxx x0x0b Not bit addressable a. Bit 2 stuck at 0; this allows to use INC AUXR1 to toggle DPS without changing GF3. ASSEMBLY LANGUAGE 59 7683C–USB–11/07 ; Block move using dual data pointers ; Modifies DPTR0, DPTR1, A and PSW ; note: DPS exits opposite of entry state ; unless an extra INC AUXR1 is added ; 00A2 AUXR1 EQU 0A2H ; 0000 909000MOV DPTR,#SOURCE ; address of SOURCE 0003 05A2 INC AUXR1 ; switch data pointers 0005 90A000 MOV DPTR,#DEST ; address of DEST 0008 LOOP: 0008 05A2 INC AUXR1 ; switch data pointers 000A E0 MOVX A,@DPTR ; get a byte from SOURCE 000B A3 INC DPTR ; increment SOURCE address 000C 05A2 INC AUXR1 ; switch data pointers 000E F0 MOVX @DPTR,A ; write the byte to DEST 000F A3 INC DPTR ; increment DEST address 0010 70F6JNZ LOOP ; check for 0 terminator 0012 05A2 INC AUXR1 ; (optional) restore DPS INC is a short (2 bytes) and fast (12 clocks) way to manipulate the DPS bit in the AUXR1 SFR. However, note that the INC instruction does not directly force the DPS bit to a particular state, but simply toggles it. In simple routines, such as the block move example, only the fact that DPS is toggled in the proper sequence matters, not its actual value. In other words, the block move routine works the same whether DPS is '0' or '1' on entry. Observe that without the last instruction (INC AUXR1), the routine will exit with DPS in the opposite state. 60 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 16. Interrupt System 16.1 Overview The AT83C5134/35/36 has a total of 11 interrupt vectors: two external interrupts (INT0 and INT1), three timer interrupts (timers 0, 1 and 2), the serial port interrupt, SPI interrupt, Keyboard interrupt, USB interrupt and the PCA global interrupt. These interrupts are shown in Figure 16-1. Figure 16-1. Interrupt Control System IT0 High priority interrupt IPH, IPL TCON.0 0 3 INT0 IE0 0 1 3 TF0 TCON.2 IT1 0 0 3 INT1 IE1 0 1 3 Interrupt Polling Sequence, Decreasing From High-to-Low Priority TF1 0 3 PCA IT 0 RI TI 3 TF2 EXF2 3 0 0 3 KBD IT 0 3 TWI IT 0 3 SPI IT 0 3 USBINT UEPINT 0 Individual Enable Global Disable Low Priority Interrupt Each of the interrupt sources can be individually enabled or disabled by setting or clearing a bit in the Interrupt Enable register (Table 16-2). This register also contains a global disable bit, which must be cleared to disable all interrupts at once. Each interrupt source can also be individually programmed to one out of four priority levels by setting or clearing a bit in the Interrupt Priority register (Table 16-3.) and in the Interrupt Priority 61 7683C–USB–11/07 High register (Table 16-4). Table 16-1. shows the bit values and priority levels associated with each combination. 16.2 Registers The PCA interrupt vector is located at address 0033H, the SPI interrupt vector is located at address 004BH and Keyboard interrupt vector is located at address 003BH. All other vectors addresses are the same as standard C52 devices. Table 16-1. Priority Level Bit Values IPH.x IPL.x Interrupt Level Priority 0 0 0 (Lowest) 0 1 1 1 0 2 1 1 3 (Highest) A low-priority interrupt can be interrupted by a high priority interrupt, but not by another low-priority interrupt. A high-priority interrupt can’t be interrupted by any other interrupt source. If two interrupt requests of different priority levels are received simultaneously, the request of higher priority level is serviced. If interrupt requests of the same priority level are received simultaneously, an internal polling sequence determines which request is serviced. Thus within each priority level there is a second priority structure determined by the polling sequence. 62 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 Table 16-2. IEN0 Register IEN0 - Interrupt Enable Register (A8h) 7 6 5 4 3 2 1 0 EA EC ET2 ES ET1 EX1 ET0 EX0 Bit Bit Number Mnemonic 7 EA 6 EC Description Enable All interrupt bit Cleared to disable all interrupts. Set to enable all interrupts. PCA interrupt enable bit Cleared to disable. Set to enable. 5 ET2 Timer 2 overflow interrupt Enable bit Cleared to disable Timer 2 overflow interrupt. Set to enable Timer 2 overflow interrupt. 4 ES Serial port Enable bit Cleared to disable serial port interrupt. Set to enable serial port interrupt. 3 ET1 Timer 1 overflow interrupt Enable bit Cleared to disable Timer 1 overflow interrupt. Set to enable Timer 1 overflow interrupt. 2 EX1 External interrupt 1 Enable bit Cleared to disable external interrupt 1. Set to enable external interrupt 1. 1 ET0 Timer 0 overflow interrupt Enable bit Cleared to disable timer 0 overflow interrupt. Set to enable timer 0 overflow interrupt. 0 EX0 External interrupt 0 Enable bit Cleared to disable external interrupt 0. Set to enable external interrupt 0. Reset Value = 0000 0000b Bit addressable 63 7683C–USB–11/07 Table 16-3. IPL0 Register IPL0 - Interrupt Priority Register (B8h) 7 6 5 4 3 2 1 0 - PPCL PT2L PSL PT1L PX1L PT0L PX0L Bit Bit Number Mnemonic 7 - 6 PPCL PCA interrupt Priority bit Refer to PPCH for priority level. 5 PT2L Timer 2 overflow interrupt Priority bit Refer to PT2H for priority level. 4 PSL Serial port Priority bit Refer to PSH for priority level. 3 PT1L Timer 1 overflow interrupt Priority bit Refer to PT1H for priority level. 2 PX1L External interrupt 1 Priority bit Refer to PX1H for priority level. 1 PT0L Timer 0 overflow interrupt Priority bit Refer to PT0H for priority level. 0 PX0L External interrupt 0 Priority bit Refer to PX0H for priority level. Description Reserved The value read from this bit is indeterminate. Do not set this bit. Reset Value = x000 0000b Bit addressable 64 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 Table 16-4. IPH0 Register IPH0 - Interrupt Priority High Register (B7h) 7 6 5 4 3 2 1 0 - PPCH PT2H PSH PT1H PX1H PT0H PX0H Bit Bit Number Mnemonic 7 - 6 5 4 3 2 1 0 Description Reserved The value read from this bit is indeterminate. Do not set this bit. PPCH PCA interrupt Priority high bit. PPCH PPCL Priority Level 0 0 Lowest 0 1 1 0 1 1 Highest PT2H Timer 2 overflow interrupt Priority High bit PT2H PT2L Priority Level 0 0 Lowest 0 1 1 0 1 1 Highest PSH Serial port Priority High bit Priority Level PSH PSL 0 0 Lowest 0 1 1 0 1 1 Highest PT1H Timer 1 overflow interrupt Priority High bit PT1H PT1L Priority Level 0 0 Lowest 0 1 1 0 1 1 Highest PX1H External interrupt 1 Priority High bit PX1H PX1L Priority Level 0 0 Lowest 0 1 1 0 1 1 Highest PT0H Timer 0 overflow interrupt Priority High bit PT0H PT0L Priority Level 0 0 Lowest 0 1 1 0 1 1 Highest PX0H External interrupt 0 Priority High bit PX0H PX0L Priority Level 0 0 Lowest 0 1 1 0 1 1 Highest Reset Value = x000 0000b Not bit addressable 65 7683C–USB–11/07 Table 16-5. IEN1 Register IEN1 - Interrupt Enable Register (B1h) 7 6 5 4 3 2 1 0 - EUSB - - - ESPI ETWI EKB Bit Bit Number Mnemonic 7 - 6 EUSB 5 - Reserved 4 - Reserved 3 - Reserved 2 ESPI SPI interrupt Enable bit Cleared to disable SPI interrupt. Set to enable SPI interrupt. 1 ETWI TWI interrupt Enable bit Cleared to disable TWI interrupt. Set to enable TWI interrupt. 0 EKB Keyboard interrupt Enable bit Cleared to disable keyboard interrupt. Set to enable keyboard interrupt. Description Reserved USB Interrupt Enable bit Cleared to disable USB interrupt. Set to enable USB interrupt. Reset Value = x0xx x000b Not bit addressable 66 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 Table 16-6. IPL1 Register IPL1 - Interrupt Priority Register (B2h) 7 6 5 4 3 2 1 0 - PUSBL - - - PSPIL PTWIL PKBDL Bit Bit Number Mnemonic 7 - 6 PUSBL 5 - Reserved The value read from this bit is indeterminate. Do not set this bit. 4 - Reserved The value read from this bit is indeterminate. Do not set this bit. 3 - Reserved The value read from this bit is indeterminate. Do not set this bit. 2 PSPIL SPI Interrupt Priority bit Refer to PSPIH for priority level. 1 PTWIL TWI Interrupt Priority bit Refer to PTWIH for priority level. 0 PKBL Keyboard Interrupt Priority bit Refer to PKBH for priority level. Description Reserved The value read from this bit is indeterminate. Do not set this bit. USB Interrupt Priority bit Refer to PUSBH for priority level. Reset Value = X0XX X000b Not bit addressable 67 7683C–USB–11/07 Table 16-7. IPH1 Register IPH1 - Interrupt Priority High Register (B3h) 7 6 5 4 3 2 1 0 - PUSBH - - - PSPIH PTWIH PKBH Bit Bit Number Mnemonic 7 - Description Reserved The value read from this bit is indeterminate. Do not set this bit. USB Interrupt Priority High bit PUSBHPUSBLPriority Level 0 0 Lowest 0 1 1 0 1 1 Highest 6 PUSBH 5 - Reserved The value read from this bit is indeterminate. Do not set this bit. 4 - Reserved The value read from this bit is indeterminate. Do not set this bit. 3 - Reserved The value read from this bit is indeterminate. Do not set this bit. 2 1 0 PSPIH SPI Interrupt Priority High bit PSPIHPSPIL Priority Level 0 0 Lowest 0 1 1 0 1 1 Highest PTWIH TWI Interrupt Priority High bit PTWIHPTWIL Priority Level 0 0 Lowest 0 1 1 0 1 1 Highest PKBH Keyboard Interrupt Priority High bit PKBH PKBL Priority Level 0 0 Lowest 0 1 1 0 1 1 Highest Reset Value = X0XX X000b Not bit addressable 68 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 16.3 Interrupt Sources and Vector Addresses Table 16-8. Vector Table Polling Priority Interrupt Source 0 0 Reset 1 1 INT0 IE0 0003h 2 2 Timer 0 TF0 000Bh 3 3 INT1 IE1 0013h 4 4 Timer 1 IF1 001Bh 5 6 UART RI+TI 0023h 6 7 Timer 2 TF2+EXF2 002Bh 7 5 PCA CF + CCFn (n = 0-4) 0033h 8 8 Keyboard KBDIT 003Bh 9 9 TWI TWIIT 0043h 10 10 SPI SPIIT 004Bh 11 11 0053h 12 12 005Bh 13 13 0063h 14 14 15 15 USB Interrupt Request Vector Number Address 0000h UEPINT + USBINT 006Bh 0073h 69 7683C–USB–11/07 17. Keyboard Interface 17.1 Introduction The AT83C5134/35/36 implements a keyboard interface allowing the connection of a 8 x n matrix keyboard. It is based on 8 inputs with programmable interrupt capability on both high or low level. These inputs are available as an alternate function of P1 and allow to exit from idle and power down modes. 17.2 Description The keyboard interface communicates with the C51 core through 3 special function registers: KBLS, the Keyboard Level Selection register (Table 17-3), KBE, The Keyboard interrupt Enable register (Table 17-2), and KBF, the Keyboard Flag register (Table 17-1). 17.2.1 Interrupt The keyboard inputs are considered as 8 independent interrupt sources sharing the same interrupt vector. An interrupt enable bit (KBD in IE1) allows global enable or disable of the keyboard interrupt (see Figure 17-1). As detailed in Figure 17-2 each keyboard input has the capability to detect a programmable level according to KBLS.x bit value. Level detection is then reported in interrupt flags KBF.x that can be masked by software using KBE.x bits. This structure allow keyboard arrangement from 1 by n to 8 by n matrix and allow usage of P1 inputs for other purpose. Figure 17-1. Keyboard Interface Block Diagram P1.0 Input Circuitry P1.1 Input Circuitry P1.2 Input Circuitry P1.3 Input Circuitry P1.4 Input Circuitry P1.5 Input Circuitry P1.6 Input Circuitry P1.7 Input Circuitry KBDIT Keyboard Interface Interrupt Request KBD IE1.0 Figure 17-2. Keyboard Input Circuitry Vcc 0 P1:x KBF.x 1 Internal Pull-up 70 KBE.x KBLS.x AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 17.2.2 17.3 Power Reduction Mode P1 inputs allow exit from idle and power down modes as detailed in section “Power-down Mode”. Registers Table 17-1. KBF Register KBF - Keyboard Flag Register (9Eh) 7 6 5 4 3 2 1 0 KBF7 KBF6 KBF5 KBF4 KBF3 KBF2 KBF1 KBF0 Bit Number Bit Mnemonic Description 7 6 5 4 3 2 1 0 KBF7 Keyboard line 7 flag Set by hardware when the Port line 7 detects a programmed level. It generates a Keyboard interrupt request if the KBKBIE.7 bit in KBIE register is set. Cleared by hardware when reading KBF SFR by software. KBF6 Keyboard line 6 flag Set by hardware when the Port line 6 detects a programmed level. It generates a Keyboard interrupt request if the KBIE.6 bit in KBIE register is set. Cleared by hardware when reading KBF SFR by software. KBF5 Keyboard line 5 flag Set by hardware when the Port line 5 detects a programmed level. It generates a Keyboard interrupt request if the KBIE.5 bit in KBIE register is set. Cleared by hardware when reading KBF SFR by software. KBF4 Keyboard line 4 flag Set by hardware when the Port line 4 detects a programmed level. It generates a Keyboard interrupt request if the KBIE.4 bit in KBIE register is set. Cleared by hardware when reading KBF SFR by software. KBF3 Keyboard line 3 flag Set by hardware when the Port line 3 detects a programmed level. It generates a Keyboard interrupt request if the KBIE.3 bit in KBIE register is set. Cleared by hardware when reading KBF SFR by software. KBF2 Keyboard line 2 flag Set by hardware when the Port line 2 detects a programmed level. It generates a Keyboard interrupt request if the KBIE.2 bit in KBIE register is set. Must be cleared by software. KBF1 Keyboard line 1 flag Set by hardware when the Port line 1 detects a programmed level. It generates a Keyboard interrupt request if the KBIE.1 bit in KBIE register is set. Cleared by hardware when reading KBF SFR by software. KBF0 Keyboard line 0 flag Set by hardware when the Port line 0 detects a programmed level. It generates a Keyboard interrupt request if the KBIE.0 bit in KBIE register is set. Cleared by hardware when reading KBF SFR by software. Reset Value = 0000 0000b 71 7683C–USB–11/07 Table 17-2. KBE Register KBE - Keyboard Input Enable Register (9Dh) 7 6 5 4 3 2 1 0 KBE7 KBE6 KBE5 KBE4 KBE3 KBE2 KBE1 KBE0 Bit Number Bit Mnemonic Description 7 KBE7 Keyboard line 7 Enable bit Cleared to enable standard I/O pin. Set to enable KBF.7 bit in KBF register to generate an interrupt request. 6 KBE6 Keyboard line 6 Enable bit Cleared to enable standard I/O pin. Set to enable KBF.6 bit in KBF register to generate an interrupt request. 5 KBE5 Keyboard line 5 Enable bit Cleared to enable standard I/O pin. Set to enable KBF.5 bit in KBF register to generate an interrupt request. 4 KBE4 Keyboard line 4 Enable bit Cleared to enable standard I/O pin. Set to enable KBF.4 bit in KBF register to generate an interrupt request. 3 KBE3 Keyboard line 3 Enable bit Cleared to enable standard I/O pin. Set to enable KBF.3 bit in KBF register to generate an interrupt request. 2 KBE2 Keyboard line 2 Enable bit Cleared to enable standard I/O pin. Set to enable KBF.2 bit in KBF register to generate an interrupt request. 1 KBE1 Keyboard line 1 Enable bit Cleared to enable standard I/O pin. Set to enable KBF.1 bit in KBF register to generate an interrupt request. 0 KBE0 Keyboard line 0 Enable bit Cleared to enable standard I/O pin. Set to enable KBF.0 bit in KBF register to generate an interrupt request. Reset Value = 0000 0000b 72 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 Table 17-3. KBLS Register KBLS-Keyboard Level Selector Register (9Ch) 7 6 5 4 3 2 1 0 KBLS7 KBLS6 KBLS5 KBLS4 KBLS3 KBLS2 KBLS1 KBLS0 Bit Number Bit Mnemonic Description 7 KBLS7 Keyboard line 7 Level Selection bit Cleared to enable a low level detection on Port line 7. Set to enable a high level detection on Port line 7. 6 KBLS6 Keyboard line 6 Level Selection bit Cleared to enable a low level detection on Port line 6. Set to enable a high level detection on Port line 6. 5 KBLS5 Keyboard line 5 Level Selection bit Cleared to enable a low level detection on Port line 5. Set to enable a high level detection on Port line 5. 4 KBLS4 Keyboard line 4 Level Selection bit Cleared to enable a low level detection on Port line 4. Set to enable a high level detection on Port line 4. 3 KBLS3 Keyboard line 3 Level Selection bit Cleared to enable a low level detection on Port line 3. Set to enable a high level detection on Port line 3. 2 KBLS2 Keyboard line 2 Level Selection bit Cleared to enable a low level detection on Port line 2. Set to enable a high level detection on Port line 2. 1 KBLS1 Keyboard line 1 Level Selection bit Cleared to enable a low level detection on Port line 1. Set to enable a high level detection on Port line 1. 0 KBLS0 Keyboard line 0 Level Selection bit Cleared to enable a low level detection on Port line 0. Set to enable a high level detection on Port line 0. Reset Value = 0000 0000b 73 7683C–USB–11/07 18. Programmable LED AT83C5134/35/36 have up to 4 programmable LED current sources, configured by the register LEDCON. Table 18-1. LEDCON Register LEDCON (S:F1h) LED Control Register 7 6 5 LED3 Bit Number 7:6 5:4 3:2 1:0 4 LED2 Bit Mnemonic 3 2 LED1 1 0 LED0 Description LED3 Port 0 0 1 1 LED3 0 1 0 1 Configuration Standard C51 Port 2 mA current source when P3.7 is low 4 mA current source when P3.7 is low 10 mA current source when P3.7 is low LED2 Port 0 0 1 1 /LED2 0 1 0 1 Configuration Standard C51 Port 2 mA current source when P3.6 is low 4 mA current source when P3.6 is low 10 mA current source when P3.6 is low LED1 Port/ LED1 0 0 0 1 1 0 1 1 Configuration Standard C51 Port 2 mA current source when P3.5 is low 4 mA current source when P3.5 is low 10 mA current source when P3.5 is low LED0 Port/ LED0 0 0 0 1 1 0 1 1 Configuration Standard C51 Port 2 mA current source when P3.3 is low 4 mA current source when P3.3 is low 10 mA current source when P3.3 is low Reset Value = 00h 74 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 19. Serial Peripheral Interface (SPI) The Serial Peripheral Interface module (SPI) allows full-duplex, synchronous, serial communication between the MCU and peripheral devices, including other MCUs. 19.1 Features Features of the SPI module include the following: • Full-duplex, three-wire synchronous transfers • Master or Slave operation • Eight programmable Master clock rates • Serial clock with programmable polarity and phase • Master mode fault error flag with MCU interrupt capability • Write collision flag protection 19.2 Signal Description Figure 19-1 shows a typical SPI bus configuration using one Master controller and many Slave peripherals. The bus is made of three wires connecting all the devices: Figure 19-1. SPI Master/Slaves Interconnection Slave 1 MISO MOSI SCK SS MISO MOSI SCK SS VDD Slave 4 Slave 3 MISO MOSI SCK SS 0 1 2 3 MISO MOSI SCK SS MISO MOSI SCK SS PORT Master Slave 2 The Master device selects the individual Slave devices by using four pins of a parallel port to control the four SS pins of the Slave devices. 19.2.1 Master Output Slave Input (MOSI) This 1-bit signal is directly connected between the Master Device and a Slave Device. The MOSI line is used to transfer data in series from the Master to the Slave. Therefore, it is an output signal from the Master, and an input signal to a Slave. A byte (8-bit word) is transmitted most significant bit (MSB) first, least significant bit (LSB) last. 19.2.2 Master Input Slave Output (MISO) This 1-bit signal is directly connected between the Slave Device and a Master Device. The MISO line is used to transfer data in series from the Slave to the Master. Therefore, it is an output signal from the Slave, and an input signal to the Master. A byte (8-bit word) is transmitted most significant bit (MSB) first, least significant bit (LSB) last. 75 7683C–USB–11/07 19.2.3 SPI Serial Clock (SCK) This signal is used to synchronize the data movement both in and out the devices through their MOSI and MISO lines. It is driven by the Master for eight clock cycles which allows to exchange one byte on the serial lines. 19.2.4 Slave Select (SS) Each Slave peripheral is selected by one Slave Select pin (SS). This signal must stay low for any message for a Slave. It is obvious that only one Master (SS high level) can drive the network. The Master may select each Slave device by software through port pins (Figure 19-1). To prevent bus conflicts on the MISO line, only one slave should be selected at a time by the Master for a transmission. In a Master configuration, the SS line can be used in conjunction with the MODF flag in the SPI Status register (SPSTA) to prevent multiple masters from driving MOSI and SCK (see Section “Error Conditions”, page 79). A high level on the SS pin puts the MISO line of a Slave SPI in a high-impedance state. The SS pin could be used as a general-purpose if the following conditions are met: • The device is configured as a Master and the SSDIS control bit in SPCON is set. This kind of configuration can be found when only one Master is driving the network and there is no way that the SS pin could be pulled low. Therefore, the MODF flag in the SPSTA will never be set(1). • The Device is configured as a Slave with CPHA and SSDIS control bits set(2) This kind of configuration can happen when the system comprises one Master and one Slave only. Therefore, the device should always be selected and there is no reason that the Master uses the SS pin to select the communicating Slave device. Notes: 1. Clearing SSDIS control bit does not clear MODF. 2. Special care should be taken not to set SSDIS control bit when CPHA =’0’ because in this mode, the SS is used to start the transmission. 19.2.5 Baud Rate In Master mode, the baud rate can be selected from a baud rate generator which is controlled by three bits in the SPCON register: SPR2, SPR1 and SPR0. The Master clock is chosen from one of seven clock rates resulting from the division of the internal clock by 2, 4, 8, 16, 32, 64 or 128. Table 19-1 gives the different clock rates selected by SPR2:SPR1:SPR0: Table 19-1. 76 SPI Master Baud Rate Selection SPR2 SPR1 SPR0 Clock Rate Baud Rate Divisor (BD) 0 0 0 Don’t Use No BRG 0 0 1 FCLK PERIPH/4 4 0 1 0 FCLK PERIPH/8 8 0 1 1 FCLK PERIPH/16 16 1 0 0 FCLK PERIPH/32 32 1 0 1 FCLK PERIPH/64 64 1 1 0 FCLK PERIPH/128 128 1 1 1 Don’t Use No BRG AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 19.3 Functional Description Figure 19-2 shows a detailed structure of the SPI module. Figure 19-2. SPI Module Block Diagram Internal Bus SPDAT Shift Register FCLK PERIPH Clock Divider /4 /8 /16 /32 /64 /128 7 6 5 4 3 2 1 0 Receive Data Register Pin Control Logic Clock Logic MOSI MISO M S Clock Select SCK SS SPR2 SPEN SSDIS MSTR CPOL CPHA SPR1 SPR0 SPCON SPI Control SPI Interrupt Request 8-bit bus 1-bit signal SPSTA SPIF 19.3.1 WCOL SSERR MODF - - - - Operating Modes The Serial Peripheral Interface can be configured as one of the two modes: Master mode or Slave mode. The configuration and initialization of the SPI module is made through one register: • The Serial Peripheral CONtrol register (SPCON) Once the SPI is configured, the data exchange is made using: • SPCON • The Serial Peripheral STAtus register (SPSTA) • The Serial Peripheral DATa register (SPDAT) During an SPI transmission, data is simultaneously transmitted (shifted out serially) and received (shifted in serially). A serial clock line (SCK) synchronizes shifting and sampling on the two serial data lines (MOSI and MISO). A Slave Select line (SS) allows individual selection of a Slave SPI device; Slave devices that are not selected do not interfere with SPI bus activities. When the Master device transmits data to the Slave device via the MOSI line, the Slave device responds by sending data to the Master device via the MISO line. This implies full-duplex transmission with both data out and data in synchronized with the same clock (Figure 19-3). 77 7683C–USB–11/07 Figure 19-3. Full-duplex Master/Slave Interconnection 8-bit Shift Register SPI Clock Generator MISO MISO MOSI MOSI SCK SS Master MCU 8-bit Shift Register SCK VDD SS VSS Slave MCU 19.3.1.1 Master Mode The SPI operates in Master mode when the Master bit, MSTR (1), in the SPCON register is set. Only one Master SPI device can initiate transmissions. Software begins the transmission from a Master SPI module by writing to the Serial Peripheral Data Register (SPDAT). If the shift register is empty, the byte is immediately transferred to the shift register. The byte begins shifting out on MOSI pin under the control of the serial clock, SCK. Simultaneously, another byte shifts in from the Slave on the Master’s MISO pin. The transmission ends when the Serial Peripheral transfer data flag, SPIF, in SPSTA becomes set. At the same time that SPIF becomes set, the received byte from the Slave is transferred to the receive data register in SPDAT. Software clears SPIF by reading the Serial Peripheral Status register (SPSTA) with the SPIF bit set, and then reading the SPDAT. 19.3.1.2 Slave Mode The SPI operates in Slave mode when the Master bit, MSTR (2) , in the SPCON register is cleared. Before a data transmission occurs, the Slave Select pin, SS, of the Slave device must be set to’0’. SS must remain low until the transmission is complete. In a Slave SPI module, data enters the shift register under the control of the SCK from the Master SPI module. After a byte enters the shift register, it is immediately transferred to the receive data register in SPDAT, and the SPIF bit is set. To prevent an overflow condition, Slave software must then read the SPDAT before another byte enters the shift register (3). A Slave SPI must complete the write to the SPDAT (shift register) at least one bus cycle before the Master SPI starts a transmission. If the write to the data register is late, the SPI transmits the data already in the shift register from the previous transmission. 19.3.2 78 Transmission Formats Software can select any of four combinations of serial clock (SCK) phase and polarity using two bits in the SPCON: the Clock POLarity (CPOL (4)) and the Clock PHAse (CPHA4). CPOL defines the default SCK line level in idle state. It has no significant effect on the transmission format. CPHA defines the edges on which the input data are sampled and the edges on which the output data are shifted (Figure 19-4 and Figure 19-5). The clock phase and polarity should be identical for the Master SPI device and the communicating Slave device. 1. The SPI module should be configured as a Master before it is enabled (SPEN set). Also the Master SPI should be configured before the Slave SPI. 2. The SPI module should be configured as a Slave before it is enabled (SPEN set). 3. The maximum frequency of the SCK for an SPI configured as a Slave is the bus clock speed. 4. Before writing to the CPOL and CPHA bits, the SPI should be disabled (SPEN =’0’). AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 Figure 19-4. Data Transmission Format (CPHA = 0) SCK cycle number 1 2 3 4 5 6 7 8 MSB bit6 bit5 bit4 bit3 bit2 bit1 LSB bit6 bit5 bit4 bit3 bit2 bit1 LSB SPEN (internal) SCK (CPOL = 0) SCK (CPOL = 1) MOSI (from Master) MISO (from Slave) MSB SS (to Slave) Capture point Figure 19-5. Data Transmission Format (CPHA = 1) 1 2 3 4 5 6 7 8 MOSI (from Master) MSB bit6 bit5 bit4 bit3 bit2 bit1 LSB MISO (from Slave) MSB bit6 bit5 bit4 bit3 bit2 bit1 SCK cycle number SPEN (internal) SCK (CPOL = 0) SCK (CPOL = 1) LSB SS (to Slave) Capture point Figure 19-6. CPHA/SS Timing MISO/MOSI Byte 1 Byte 2 Byte 3 Master SS Slave SS (CPHA = 0) Slave SS (CPHA = 1) As shown in Figure 19-5, the first SCK edge is the MSB capture strobe. Therefore the Slave must begin driving its data before the first SCK edge, and a falling edge on the SS pin is used to start the transmission. The SS pin must be toggled high and then low between each byte transmitted (Figure 19-2). Figure 19-6 shows an SPI transmission in which CPHA is’1’. In this case, the Master begins driving its MOSI pin on the first SCK edge. Therefore the Slave uses the first SCK edge as a start transmission signal. The SS pin can remain low between transmissions (Figure 19-1). This format may be preferable in systems having only one Master and only one Slave driving the MISO data line. 19.3.3 Error Conditions The following flags in the SPSTA signal SPI error conditions: 79 7683C–USB–11/07 19.3.3.1 Mode Fault (MODF) Mode Fault error in Master mode SPI indicates that the level on the Slave Select (SS) pin is inconsistent with the actual mode of the device. MODF is set to warn that there may have a multi-master conflict for system control. In this case, the SPI system is affected in the following ways: • An SPI receiver/error CPU interrupt request is generated, • The SPEN bit in SPCON is cleared. This disable the SPI, • The MSTR bit in SPCON is cleared When SS DISable (SSDIS) bit in the SPCON register is cleared, the MODF flag is set when the SS signal becomes “0”. However, as stated before, for a system with one Master, if the SS pin of the Master device is pulled low, there is no way that another Master attempt to drive the network. In this case, to prevent the MODF flag from being set, software can set the SSDIS bit in the SPCON register and therefore making the SS pin as a general-purpose I/O pin. Clearing the MODF bit is accomplished by a read of SPSTA register with MODF bit set, followed by a write to the SPCON register. SPEN Control bit may be restored to its original set state after the MODF bit has been cleared. 19.3.3.2 Write Collision (WCOL) A Write Collision (WCOL) flag in the SPSTA is set when a write to the SPDAT register is done during a transmit sequence. WCOL does not cause an interruption, and the transfer continues uninterrupted. Clearing the WCOL bit is done through a software sequence of an access to SPSTA and an access to SPDAT. 19.3.3.3 Overrun Condition An overrun condition occurs when the Master device tries to send several data bytes and the Slave devise has not cleared the SPIF bit issuing from the previous data byte transmitted. In this case, the receiver buffer contains the byte sent after the SPIF bit was last cleared. A read of the SPDAT returns this byte. All others bytes are lost. This condition is not detected by the SPI peripheral. 19.3.4 Interrupts Two SPI status flags can generate a CPU interrupt requests: Table 19-2. SPI Interrupts Flag Request SPIF (SP Data Transfer) SPI Transmitter Interrupt request MODF (Mode Fault) SPI Receiver/Error Interrupt Request (if SSDIS = “0”) Serial Peripheral data transfer flag, SPIF: This bit is set by hardware when a transfer has been completed. SPIF bit generates transmitter CPU interrupt requests. 80 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 Mode Fault flag, MODF: This bit becomes set to indicate that the level on the SS is inconsistent with the mode of the SPI. MODF with SSDIS reset, generates receiver/error CPU interrupt requests. Figure 19-7 gives a logical view of the above statements. Figure 19-7. SPI Interrupt Requests Generation SPIF SPI Transmitter CPU Interrupt Request SPI CPU Interrupt Request MODF SPI Receiver/Error CPU Interrupt Request SSDIS 19.3.5 Registers There are three registers in the module that provide control, status and data storage functions. These registers are describes in the following paragraphs. 19.3.5.1 Serial Peripheral Control Register (SPCON) • The Serial Peripheral Control Register does the following: – Selects one of the Master clock rates – Configure the SPI module as Master or Slave – Selects serial clock polarity and phase – Enables the SPI module – Frees the SS pin for a general-purpose Table 19-3 describes this register and explains the use of each bit. Table 19-3. SPCON Register 7 6 5 4 3 2 1 0 SPR2 SPEN SSDIS MSTR CPOL CPHA SPR1 SPR0 Bit Number Bit Mnemonic 7 SPR2 6 SPEN Description Serial Peripheral Rate 2 Bit with SPR1 and SPR0 define the clock rate. Serial Peripheral Enable Cleared to disable the SPI interface. Set to enable the SPI interface. SS Disable 5 SSDIS 5 MSTR Cleared to enable SS in both Master and Slave modes. Set to disable SS in both Master and Slave modes. In Slave mode, this bit has no effect if CPHA = “0”. Serial Peripheral Master Cleared to configure the SPI as a Slave. Set to configure the SPI as a Master. Clock Polarity 4 CPOL Cleared to have the SCK set to “0” in idle state. Set to have the SCK set to “1” in idle state. 81 7683C–USB–11/07 Bit Number Bit Mnemonic 3 CPHA Description Clock Phase Cleared to have the data sampled when the SCK leaves the idle state (see CPOL). Set to have the data sampled when the SCK returns to idle state (see CPOL). 2 1 SPR1 SPR0 SPR2 SPR1 SPR0 0 0 0 Serial Peripheral Rate Reserved 0 0 1 FCLK PERIPH/4 0 1 0 FCLK PERIPH/8 0 1 1 FCLK PERIPH/16 1 0 0 FCLK PERIPH/32 1 0 1 FCLK PERIPH/64 1 1 0 FCLK PERIPH/128 1 1 1 Reserved Reset Value = 0001 0100b Not bit addressable 19.3.5.2 Serial Peripheral Status Register (SPSTA) The Serial Peripheral Status Register contains flags to signal the following conditions: • Data transfer complete • Write collision • Inconsistent logic level on SS pin (mode fault error) Table 19-4 describes the SPSTA register and explains the use of every bit in the register. Table 19-4. SPSTA Register SPSTA - Serial Peripheral Status and Control register (0C4H) Table 3. 7 6 5 4 3 2 1 0 SPIF WCOL SSERR MODF - - - - Bit Number Bit Mnemonic Description Serial Peripheral data transfer flag 7 SPIF Cleared by hardware to indicate data transfer is in progress or has been approved by a clearing sequence. Set by hardware to indicate that the data transfer has been completed. Write Collision flag 6 WCOL Cleared by hardware to indicate that no collision has occurred or has been approved by a clearing sequence. Set by hardware to indicate that a collision has been detected. Synchronous Serial Slave Error flag 5 SSERR Set by hardware when SS is deasserted before the end of a received data. Cleared by disabling the SPI (clearing SPEN bit in SPCON). 82 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 Bit Number Bit Mnemonic Description Mode Fault 4 MODF Cleared by hardware to indicate that the SS pin is at appropriate logic level, or has been approved by a clearing sequence. Set by hardware to indicate that the SS pin is at inappropriate logic level. 3 - 2 - 1 - 0 - Reserved The value read from this bit is indeterminate. Do not set this bit Reserved The value read from this bit is indeterminate. Do not set this bit Reserved The value read from this bit is indeterminate. Do not set this bit. Reserved The value read from this bit is indeterminate. Do not set this bit. Reset Value = 00X0 XXXXb Not Bit addressable 19.3.5.3 Serial Peripheral Data Register (SPDAT) The Serial Peripheral Data Register (Table 19-5) is a read/write buffer for the receive data register. A write to SPDAT places data directly into the shift register. No transmit buffer is available in this model. A Read of the SPDAT returns the value located in the receive buffer and not the content of the shift register. Table 19-5. SPDAT Register SPDAT - Serial Peripheral Data Register (0C5H) 7 6 5 4 3 2 1 0 R7 R6 R5 R4 R3 R2 R1 R0 Reset Value = Indeterminate R7:R0: Receive data bits SPCON, SPSTA and SPDAT registers may be read and written at any time while there is no ongoing exchange. However, special care should be taken when writing to them while a transmission is on-going: • Do not change SPR2, SPR1 and SPR0 • Do not change CPHA and CPOL • Do not change MSTR • Clearing SPEN would immediately disable the peripheral • Writing to the SPDAT will cause an overflow 83 7683C–USB–11/07 20. Two Wire Interface (TWI) This section describes the 2-wire interface. The 2-wire bus is a bi-directional 2-wire serial communication standard. It is designed primarily for simple but efficient integrated circuit (IC) control. The system is comprised of two lines, SCL (Serial Clock) and SDA (Serial Data) that carry information between the ICs connected to them. The serial data transfer is limited to 100 Kbit/s in standard mode. Various communication configuration can be designed using this bus. Figure 20-1 shows a typical 2-wire bus configuration. All the devices connected to the bus can be master and slave. Figure 20-1. 2-wire Bus Configuration device1 device2 device3 ... deviceN SCL SDA 84 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 Figure 20-2. Block Diagram 8 Address Register SSADR Comparator Input Filter SDA Output Stage SSDAT ACK Shift Register Arbitration & Sink Logic Input Filter SCL Output Stage Timing & Control logic FCLK PERIPH/4 Internal Bus 8 Interrupt Serial clock generator Timer 1 overflow SSCON Control Register 7 Status Bits SSCS Status Decoder Status Register 8 85 7683C–USB–11/07 20.1 Description The CPU interfaces to the 2-wire logic via the following four 8-bit special function registers: the Synchronous Serial Control register (SSCON; Table 20-10), the Synchronous Serial Data register (SSDAT; Table 20-11), the Synchronous Serial Control and Status register (SSCS; Table 2012) and the Synchronous Serial Address register (SSADR Table 20-13). SSCON is used to enable the TWI interface, to program the bit rate (see Table 20-3), to enable slave modes, to acknowledge or not a received data, to send a START or a STOP condition on the 2-wire bus, and to acknowledge a serial interrupt. A hardware reset disables the TWI module. SSCS contains a status code which reflects the status of the 2-wire logic and the 2-wire bus. The three least significant bits are always zero. The five most significant bits contains the status code. There are 26 possible status codes. When SSCS contains F8h, no relevant state information is available and no serial interrupt is requested. A valid status code is available in SSCS one machine cycle after SI is set by hardware and is still present one machine cycle after SI has been reset by software. to Table 20-9. give the status for the master modes and miscellaneous states. SSDAT contains a byte of serial data to be transmitted or a byte which has just been received. It is addressable while it is not in process of shifting a byte. This occurs when 2-wire logic is in a defined state and the serial interrupt flag is set. Data in SSDAT remains stable as long as SI is set. While data is being shifted out, data on the bus is simultaneously shifted in; SSDAT always contains the last byte present on the bus. SSADR may be loaded with the 7-bit slave address (7 most significant bits) to which the TWI module will respond when programmed as a slave transmitter or receiver. The LSB is used to enable general call address (00h) recognition. Figure 20-3 shows how a data transfer is accomplished on the 2-wire bus. Figure 20-3. Complete Data Transfer on 2-wire Bus MSB SDA acknowledgement signal from receiver acknowledgement signal from receiver SCL 1 2 S start condition 7 8 9 ACK 1 2 3-8 9 ACK clock line held low while interrupts are serviced P stop condition The four operating modes are: • Master Transmitter • Master Receiver • Slave transmitter • Slave receiver Data transfer in each mode of operation is shown in Table to Table 20-9 and Figure 20-4. to Figure 20-7.. These figures contain the following abbreviations: S 86 : START condition AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 R : Read bit (high level at SDA) W : Write bit (low level at SDA) A: Acknowledge bit (low level at SDA) A: Not acknowledge bit (high level at SDA) Data: 8-bit data byte P : STOP condition In Figure 20-4 to Figure 20-7, circles are used to indicate when the serial interrupt flag is set. The numbers in the circles show the status code held in SSCS. At these points, a service routine must be executed to continue or complete the serial transfer. These service routines are not critical since the serial transfer is suspended until the serial interrupt flag is cleared by software. When the serial interrupt routine is entered, the status code in SSCS is used to branch to the appropriate service routine. For each status code, the required software action and details of the following serial transfer are given in Table to Table 20-9. 20.1.1 Master Transmitter Mode In the master transmitter mode, a number of data bytes are transmitted to a slave receiver (Figure 20-4). Before the master transmitter mode can be entered, SSCON must be initialised as follows: Table 20-1. SSCON Initialization CR2 SSIE STA STO SI AA CR1 CR0 bit rate 1 0 0 0 X bit rate bit rate CR0, CR1 and CR2 define the internal serial bit rate if external bit rate generator is not used. SSIE must be set to enable TWI. STA, STO and SI must be cleared. The master transmitter mode may now be entered by setting the STA bit. The 2-wire logic will now test the 2-wire bus and generate a START condition as soon as the bus becomes free. When a START condition is transmitted, the serial interrupt flag (SI bit in SSCON) is set, and the status code in SSCS will be 08h. This status must be used to vector to an interrupt routine that loads SSDAT with the slave address and the data direction bit (SLA+W). When the slave address and the direction bit have been transmitted and an acknowledgement bit has been received, SI is set again and a number of status code in SSCS are possible. There are 18h, 20h or 38h for the master mode and also 68h, 78h or B0h if the slave mode was enabled (AA=logic 1). The appropriate action to be taken for each of these status code is detailed in Table . This scheme is repeated until a STOP condition is transmitted. SSIE, CR2, CR1 and CR0 are not affected by the serial transfer and are referred to Table 7 to Table 11. After a repeated START condition (state 10h) the TWI module may switch to the master receiver mode by loading SSDAT with SLA+R. 20.1.2 Master Receiver Mode In the master receiver mode, a number of data bytes are received from a slave transmitter (Figure 20-5). The transfer is initialized as in the master transmitter mode. When the START condition has been transmitted, the interrupt routine must load SSDAT with the 7-bit slave 87 7683C–USB–11/07 address and the data direction bit (SLA+R). The serial interrupt flag SI must then be cleared before the serial transfer can continue. When the slave address and the direction bit have been transmitted and an acknowledgement bit has been received, the serial interrupt flag is set again and a number of status code in SSCS are possible. There are 40h, 48h or 38h for the master mode and also 68h, 78h or B0h if the slave mode was enabled (AA=logic 1). The appropriate action to be taken for each of these status code is detailed in Table . This scheme is repeated until a STOP condition is transmitted. SSIE, CR2, CR1 and CR0 are not affected by the serial transfer and are referred to Table 7 to Table 11. After a repeated START condition (state 10h) the TWI module may switch to the master transmitter mode by loading SSDAT with SLA+W. 20.1.3 Slave Receiver Mode In the slave receiver mode, a number of data bytes are received from a master transmitter (Figure 20-6). To initiate the slave receiver mode, SSADR and SSCON must be loaded as follows: Table 20-2. SSADR: Slave Receiver Mode Initialization A6 A5 A4 A3 A2 A1 A0 GC own slave address The upper 7 bits are the address to which the TWI module will respond when addressed by a master. If the LSB (GC) is set the TWI module will respond to the general call address (00h); otherwise it ignores the general call address. Table 20-3. SSCON: Slave Receiver Mode Initialization CR2 SSIE STA STO SI AA CR1 CR0 bit rate 1 0 0 0 1 bit rate bit rate CR0, CR1 and CR2 have no effect in the slave mode. SSIE must be set to enable the TWI. The AA bit must be set to enable the own slave address or the general call address acknowledgement. STA, STO and SI must be cleared. When SSADR and SSCON have been initialised, the TWI module waits until it is addressed by its own slave address followed by the data direction bit which must be at logic 0 (W) for the TWI to operate in the slave receiver mode. After its own slave address and the W bit have been received, the serial interrupt flag is set and a valid status code can be read from SSCS. This status code is used to vector to an interrupt service routine.The appropriate action to be taken for each of these status code is detailed in Table . The slave receiver mode may also be entered if arbitration is lost while TWI is in the master mode (states 68h and 78h). If the AA bit is reset during a transfer, TWI module will return a not acknowledge (logic 1) to SDA after the next received data byte. While AA is reset, the TWI module does not respond to its own slave address. However, the 2-wire bus is still monitored and address recognition may be resume at any time by setting AA. This means that the AA bit may be used to temporarily isolate the module from the 2-wire bus. 88 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 20.1.4 Slave Transmitter Mode In the slave transmitter mode, a number of data bytes are transmitted to a master receiver (Figure 20-7). Data transfer is initialized as in the slave receiver mode. When SSADR and SSCON have been initialized, the TWI module waits until it is addressed by its own slave address followed by the data direction bit which must be at logic 1 (R) for TWI to operate in the slave transmitter mode. After its own slave address and the R bit have been received, the serial interrupt flag is set and a valid status code can be read from SSCS. This status code is used to vector to an interrupt service routine. The appropriate action to be taken for each of these status code is detailed in Table . The slave transmitter mode may also be entered if arbitration is lost while the TWI module is in the master mode. If the AA bit is reset during a transfer, the TWI module will transmit the last byte of the transfer and enter state C0h or C8h. the TWI module is switched to the not addressed slave mode and will ignore the master receiver if it continues the transfer. Thus the master receiver receives all 1’s as serial data. While AA is reset, the TWI module does not respond to its own slave address. However, the 2-wire bus is still monitored and address recognition may be resume at any time by setting AA. This means that the AA bit may be used to temporarily isolate the TWI module from the 2-wire bus. 20.1.5 Miscellaneous States There are two SSCS codes that do not correspond to a define TWI hardware state (Table 20-9 ). These codes are discuss hereafter. Status F8h indicates that no relevant information is available because the serial interrupt flag is not set yet. This occurs between other states and when the TWI module is not involved in a serial transfer. Status 00h indicates that a bus error has occurred during a TWI serial transfer. A bus error is caused when a START or a STOP condition occurs at an illegal position in the format frame. Examples of such illegal positions happen during the serial transfer of an address byte, a data byte, or an acknowledge bit. When a bus error occurs, SI is set. To recover from a bus error, the STO flag must be set and SI must be cleared. This causes the TWI module to enter the not addressed slave mode and to clear the STO flag (no other bits in SSCON are affected). The SDA and SCL lines are released and no STOP condition is transmitted. 20.2 Notes the TWI module interfaces to the external 2-wire bus via two port pins: SCL (serial clock line) and SDA (serial data line). To avoid low level asserting on these lines when the TWI module is enabled, the output latches of SDA and SLC must be set to logic 1. Table 20-4. Bit Frequency Configuration Bit Frequency ( kHz) CR2 CR1 CR0 FOSCA= 12 MHz FOSCA = 16 MHz FOSCA divided by 0 0 0 47 62.5 256 0 0 1 53.5 71.5 224 0 1 0 62.5 83 192 0 1 1 75 100 160 89 7683C–USB–11/07 Bit Frequency ( kHz) CR2 CR1 CR0 FOSCA= 12 MHz FOSCA = 16 MHz FOSCA divided by 1 0 0 - - Unused 1 0 1 100 133.3 120 1 1 0 200 266.6 60 1 1 1 0.5 <. < 62.5 0.67 <. < 83 Timer 1 in mode 2 can be used as TWI baudrate generator with the following formula: 96.(256-”Timer1 reload value”) Figure 20-4. Format and State in the Master Transmitter Mode MT Successfull transmission to a slave receiver S SLA 08h W A Data A P 28h 18h Next transfer started with a repeated start condition S SLA W 10h Not acknowledge received after the slave address A R P 20h MR Not acknowledge received after a data byte A P 30h Arbitration lost in slave address or data byte A or A Other master continues 38h Arbitration lost and addressed as slave From master to slave AT83C5134/35/36 From slave to master Other master continues 38h Other master continues A 68h 90 A or A Data 78h A B0h To corresponding states in slave mode Any number of data bytes and their associated acknowledge bits 7683C–USB–11/07 n This number (contained in SSCS) corresponds to a defined state of the 2-wire bus AT83C5134/35/36 Table 20-5. Status in Master Transmitter Mode Application software response Status Code SSSTA Status of the Twowire Bus and Twowire Hardware To SSCON To/From SSDAT SSSTA SSSTO SSI SSAA Next Action Taken by Two-wire Hardware 08h A START condition has Write SLA+W been transmitted X 0 0 X Write SLA+W X 0 0 X 10h A repeated START condition has been transmitted Write SLA+R X 0 0 X Write data byte 0 0 0 X No SSDAT action 1 0 0 X No SSDAT action 0 1 0 X STOP condition will be transmitted and SSSTO flag will be reset. No SSDAT action 1 1 0 X STOP condition followed by a START condition will be transmitted and SSSTO flag will be reset. Write data byte 0 0 0 X No SSDAT action 1 0 0 X No SSDAT action 0 1 0 X STOP condition will be transmitted and SSSTO flag will be reset. No SSDAT action 1 1 0 X STOP condition followed by a START condition will be transmitted and SSSTO flag will be reset. Write data byte 0 0 0 X No SSDAT action 1 0 0 X No SSDAT action 0 1 0 X STOP condition will be transmitted and SSSTO flag will be reset. No SSDAT action 1 1 0 X STOP condition followed by a START condition will be transmitted and SSSTO flag will be reset. Write data byte 0 0 0 X No SSDAT action 1 0 0 X No SSDAT action 0 1 0 X STOP condition will be transmitted and SSSTO flag will be reset. No SSDAT action 1 1 0 X STOP condition followed by a START condition will be transmitted and SSSTO flag will be reset. No SSDAT action 0 0 0 X Two-wire bus will be released and not addressed slave mode will be entered. No SSDAT action 1 0 0 X A START condition will be transmitted when the bus becomes free. 18h 20h 28h 30h 38h SLA+W has been transmitted; ACK has been received SLA+W has been transmitted; NOT ACK has been received Data byte has been transmitted; ACK has been received Data byte has been transmitted; NOT ACK has been received Arbitration lost in SLA+W or data bytes 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. Data byte will be transmitted. Repeated START will be transmitted. Data byte will be transmitted. Repeated START will be transmitted. Data byte will be transmitted. Repeated START will be transmitted. 91 7683C–USB–11/07 Figure 20-5. Format and State in the Master Receiver Mode MR Successfull transmission to a slave receiver S SLA 08h R Data A A 50h 40h Data A P 58h Next transfer started with a repeated start condition S SLA R 10h Not acknowledge received after the slave address A W P MT 48h Arbitration lost in slave address or acknowledge bit A or A Other master continues 38h Arbitration lost and addressed as slave From slave to master 92 Other master continues 38h Other master continues A 68h From master to slave A Data n 78h A B0h To corresponding states in slave mode Any number of data bytes and their associated acknowledge bits This number (contained in SSCS) corresponds to a defined state of the 2-wire bus AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 Table 20-6. Status in Master Receiver Mode Application software response Status Code SSSTA Status of the Twowire Bus and Twowire Hardware To SSCON To/From SSDAT SSSTA SSSTO SSI SSAA Next Action Taken by Two-wire Hardware 08h A START condition has Write SLA+R been transmitted X 0 0 X Write SLA+R X 0 0 X 10h A repeated START condition has been transmitted Write SLA+W X 0 0 X SLA+W will be transmitted. Logic will switch to master transmitter mode. Arbitration lost in SLA+R or NOT ACK bit No SSDAT action 0 0 0 X Two-wire bus will be released and not addressed slave mode will be entered. No SSDAT action 1 0 0 X A START condition will be transmitted when the bus becomes free. SLA+R has been transmitted; ACK has been received No SSDAT action 0 0 0 0 Data byte will be received and NOT ACK will be returned. No SSDAT action 0 0 0 1 Data byte will be received and ACK will be returned. No SSDAT action 1 0 0 X No SSDAT action 0 1 0 X STOP condition will be transmitted and SSSTO flag will be reset. No SSDAT action 1 1 0 X STOP condition followed by a START condition will be transmitted and SSSTO flag will be reset. Read data byte 0 0 0 0 Data byte will be received and NOT ACK will be returned. Read data byte 0 0 0 1 Data byte will be received and ACK will be returned. Read data byte 1 0 0 X Read data byte 0 1 0 X STOP condition will be transmitted and SSSTO flag will be reset. Read data byte 1 1 0 X STOP condition followed by a START condition will be transmitted and SSSTO flag will be reset. 38h 40h 48h 50h 58h SLA+R has been transmitted; NOT ACK has been received Data byte has been received; ACK has been returned Data byte has been received; NOT ACK has been returned SLA+R will be transmitted. SLA+R will be transmitted. Repeated START will be transmitted. Repeated START will be transmitted. 93 7683C–USB–11/07 Figure 20-6. Format and State in the Slave Receiver Mode Reception of the own slave address and one or more data bytes. All are acknowledged. S SLA W Data A 60h A Data 80h Last data byte received is not acknowledged. A P or S 80h A0h A 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 Data A 70h Last data byte received is not acknowledged. A 90h Data A P or S 90h A0h A P or S 98h A Arbitration lost as master and addressed as slave by general call 78h From master to slave From slave to master 94 Data n A Any number of data bytes and their associated acknowledge bits This number (contained in SSCS) corresponds to a defined state of the 2-wire bus AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 Table 20-7. Status in Slave Receiver Mode Application Software Response Status Code (SSCS) To/from SSDAT Status of the 2-wire bus and 2-wire hardware Own SLA+W has been received; ACK has been returned 60h 68h 70h 78h 80h 88h Arbitration lost in SLA+R/W as master; own SLA+W has been received; ACK has been returned 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 own SLA+W; data has been received; ACK has been returned Previously addressed with own SLA+W; data has been received; NOT ACK has been returned 90h Previously addressed with general call; data has been received; ACK has been returned To SSCON STA STO SI AA Next Action Taken By 2-wire Software No SSDAT action or X 0 0 0 Data byte will be received and NOT ACK will be returned No SSDAT action X 0 0 1 Data byte will be received and ACK will be returned No SSDAT action or X 0 0 0 Data byte will be received and NOT ACK will be returned No SSDAT action X 0 0 1 Data byte will be received and ACK will be returned No SSDAT action or X 0 0 0 Data byte will be received and NOT ACK will be returned No SSDAT action X 0 0 1 Data byte will be received and ACK will be returned No SSDAT action or X 0 0 0 Data byte will be received and NOT ACK will be returned No SSDAT action X 0 0 1 Data byte will be received and ACK will be returned No SSDAT action or X 0 0 0 Data byte will be received and NOT ACK will be returned No SSDAT action X 0 0 1 Data byte will be received and ACK will be returned Read data byte or 0 0 0 0 Read data byte or 0 0 0 1 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 recognised; GCA will be recognised if GC=logic 1 Read data byte or 1 0 0 0 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 Read data byte 1 0 0 1 Switched to the not addressed slave mode; own SLA will be recognised; GCA will be recognised if GC=logic 1. A START condition will be transmitted when the bus becomes free Read data byte or X 0 0 0 Data byte will be received and NOT ACK will be returned Read data byte X 0 0 1 Data byte will be received and ACK will be returned 95 7683C–USB–11/07 Table 20-7. Status in Slave Receiver Mode (Continued) Application Software Response Status Code (SSCS) 98h To/from SSDAT Status of the 2-wire bus and 2-wire hardware Previously addressed with general call; data has been received; NOT ACK has been returned STA A0h SI AA 0 0 0 0 Read data byte or 0 0 0 1 Read data byte or 1 1 0 0 0 0 1 0 0 No SSDAT action or 0 0 0 1 1 0 0 0 0 Switched to the not addressed slave mode; own SLA will be recognised; GCA will be recognised if GC=logic 1 Switched to the not addressed slave mode; own SLA will be recognised; GCA will be recognised if GC=logic 1. A START condition will be transmitted when the bus becomes free 0 1 Switched to the not addressed slave mode; no recognition of own SLA or GCA 0 0 No SSDAT action or Next Action Taken By 2-wire Software 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 No SSDAT action or No SSDAT action 96 STO Read data byte or Read data byte A STOP condition or repeated START condition has been received while still addressed as slave To SSCON 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 recognised; GCA will be recognised if GC=logic 1 0 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 1 Switched to the not addressed slave mode; own SLA will be recognised; GCA will be recognised if GC=logic 1. A START condition will be transmitted when the bus becomes free AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 Figure 20-7. Format and State in the Slave Transmitter Mode Reception of the S own slave address and one or more data bytes SLA A R Data A A8h Arbitration lost as master and addressed as slave B8h Data A P or S C0h A B0h Last data byte transmitted. Switched to not addressed slave (AA=0) A All 1’s P or S C8h From master to slave Data From slave to master Table 20-8. A Any number of data bytes and their associated acknowledge bits This number (contained in SSCS) corresponds to a defined state of the 2-wire bus n Status in Slave Transmitter Mode Application Software Response Status Code (SSCS) To/from SSDAT Status of the 2-wire bus and 2-wire hardware Own SLA+R has been received; ACK has been returned A8h B0h B8h 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; NOT ACK has been received To SSCON STA STO SI AA Next Action Taken By 2-wire Software Load data byte or X 0 0 0 Last data byte will be transmitted and NOT ACK will be received Load data byte X 0 0 1 Data byte will be transmitted and ACK will be received Load data byte or X 0 0 0 Last data byte will be transmitted and NOT ACK will be received Load data byte X 0 0 1 Data byte will be transmitted and ACK will be received Load data byte or X 0 0 0 Last data byte will be transmitted and NOT ACK will be received Load data byte X 0 0 1 Data byte will be transmitted and ACK will be received 97 7683C–USB–11/07 Table 20-8. Status in Slave Transmitter Mode (Continued) Application Software Response Status Code (SSCS) C0h To/from SSDAT Status of the 2-wire bus and 2-wire hardware Data byte in SSDAT has been transmitted; NOT ACK has been received STA Last data byte in SSDAT has been transmitted (AA=0); ACK has been received SI AA 0 0 0 0 No SSDAT action or 0 0 0 1 No SSDAT action or 1 0 1 0 0 0 1 0 0 No SSDAT action or 0 0 0 1 0 1 0 0 0 Switched to the not addressed slave mode; own SLA will be recognised; GCA will be recognised if GC=logic 1 Switched to the not addressed slave mode; own SLA will be recognised; GCA will be recognised if GC=logic 1. A START condition will be transmitted when the bus becomes free 0 1 Switched to the not addressed slave mode; no recognition of own SLA or GCA 0 0 No SSDAT action or Next Action Taken By 2-wire Software 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 No SSDAT action or No SSDAT action Table 20-9. STO No SSDAT action or No SSDAT action C8h To SSCON 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 recognised; GCA will be recognised if GC=logic 1 0 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 1 Switched to the not addressed slave mode; own SLA will be recognised; GCA will be recognised if GC=logic 1. A START condition will be transmitted when the bus becomes free Miscellaneous Status Application Software Response Status Code (SSCS) 98 To/from SSDAT Status of the 2-wire bus and 2-wire hardware To SSCON STA F8h No relevant state information available; SI= 0 No SSDAT action 00h Bus error due to an illegal START or STOP condition No SSDAT action STO SI AA No SSCON action 0 1 0 Next Action Taken By 2-wire Software Wait or proceed current transfer X Only the internal hardware is affected, no STOP condition is sent on the bus. In all cases, the bus is released and STO is reset. AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 20.3 Registers Table 20-10. SSCON Register SSCON - Synchronous Serial Control Register (93h) 7 6 5 4 3 2 1 0 CR2 SSIE STA STO SI AA CR1 CR0 Bit Number Bit Mnemonic Description 7 CR2 Control Rate bit 2 See . 6 SSIE Synchronous Serial Interface Enable bit Clear to disable SSLC. Set to enable SSLC. 5 STA Start flag Set to send a START condition on the bus. 4 ST0 Stop flag Set to send a STOP condition on the bus. 3 SI Synchronous Serial Interrupt flag Set by hardware when a serial interrupt is requested. Must be cleared by software to acknowledge interrupt. 2 AA Assert Acknowledge flag Clear in master and slave receiver modes, to force a not acknowledge (high level on SDA). Clear to disable SLA or GCA recognition. Set to recognise SLA or GCA (if GC set) for entering slave receiver or transmitter modes. Set in master and slave receiver modes, to force an acknowledge (low level on SDA). This bit has no effect when in master transmitter mode. 1 CR1 Control Rate bit 1 See Table 20-4 0 CR0 Control Rate bit 0 See Table 20-4 Table 20-11. SSDAT (095h) - Synchronous Serial Data Register (read/write) SD7 SD6 SD5 SD4 SD3 SD2 SD1 SD0 7 6 5 4 3 2 1 0 Bit Number Bit Mnemonic Description 7 SD7 Address bit 7 or Data bit 7. 6 SD6 Address bit 6 or Data bit 6. 5 SD5 Address bit 5 or Data bit 5. 4 SD4 Address bit 4 or Data bit 4. 3 SD3 Address bit 3 or Data bit 3. 2 SD2 Address bit 2 or Data bit 2. 99 7683C–USB–11/07 Bit Number Bit Mnemonic 1 SD1 Address bit 1 or Data bit 1. 0 SD0 Address bit 0 (R/W) or Data bit 0. Description Table 20-12. SSCS (094h) Read - Synchronous Serial Control and Status Register 7 6 5 4 3 2 1 0 SC4 SC3 SC2 SC1 SC0 0 0 0 Bit Number Bit Mnemonic Description 0 0 Always zero 1 0 Always zero 2 0 Always zero 3 SC0 4 SC1 5 SC2 Status Code bit 2 See Table 20-5 to Table 20-9 6 SC3 Status Code bit 3 See Table 20-5 to Table 20-9 7 SC4 Status Code bit 4 See Table 20-5 to Table 20-9 Status Code bit 0 See Table 20-5 to Table 20-9 Status Code bit 1 See Table 20-5 to Table 20-9 Table 20-13. SSADR (096h) - Synchronous Serial Address Register (read/write) 100 7 6 5 4 3 2 1 0 A7 A6 A5 A4 A3 A2 A1 A0 Bit Number Bit Mnemonic Description 7 A7 Slave address bit 7. 6 A6 Slave address bit 6. 5 A5 Slave address bit 5. 4 A4 Slave address bit 4. 3 A3 Slave address bit 3. 2 A2 Slave address bit 2. 1 A1 Slave address bit 1. 0 GC General call bit Clear to disable the general call address recognition. Set to enable the general call address recognition. AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 21. USB Controller . 21.1 Description The USB device controller provides the hardware that the AT89C5131 needs to interface a USB link to a data flow stored in a double port memory (DPRAM). The USB controller requires a 48 MHz ±0.25% reference clock, which is the output of the AT89C5131 PLL (see Section “PLL”, page 14) divided by a clock prescaler. This clock is used to generate a 12 MHz Full-speed bit clock from the received USB differential data and to transmit data according to full speed USB device tolerance. Clock recovery is done by a Digital Phase Locked Loop (DPLL) block, which is compliant with the jitter specification of the USB bus. The Serial Interface Engine (SIE) block performs NRZI encoding and decoding, bit stuffing, CRC generation and checking, and the serial-parallel data conversion. The Universal Function Interface (UFI) realizes the interface between the data flow and the Dual Port RAM. Figure 21-1. USB Device Controller Block Diagram 48 MHz +/- 0.25% DPLL 12 MHz D+ D- C51 Microcontroller Interface USB D+/DBuffer UFI Up to 48 MHz UC_sysclk SIE 21.1.1 Serial Interface Engine (SIE) The SIE performs the following functions: • NRZI data encoding and decoding. • Bit stuffing and un-stuffing. • CRC generation and checking. • Handshakes. • TOKEN type identifying. 101 7683C–USB–11/07 • Address checking. • Clock generation (via DPLL). Figure 21-2. SIE Block Diagram End of Packet Detection SYNC Detection Start of Packet Detection NRZI ‘NRZ Bit Un-stuffing Packet Bit Counter D+ D- Clock Recovery Clk48 (48 MHz) SysClk (12 MHz) PID Decoder Address Decoder DataOut 8 Serial to Parallel CRC5 and CRC16 Generation/Check USB Pattern Generator Parallel to Serial Converter Bit Stuffing NRZI Converter 8 DataIn [7:0] CRC16 Generator 21.1.2 102 Function Interface Unit (FIU) The Function Interface Unit provides the interface between the AT89C5131 and the SIE. It manages transactions at the packet level with minimal intervention from the device firmware, which reads and writes the endpoint FIFOs. AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 Figure 21-3. UFI Block Diagram FIU DPLL Asynchronous Information CSREG 0 to 7 Transfer Transfer Control Registers FSM Endpoint 5 Bank Endpoint 4 Endpoint 3 Endpoint 2 Endpoint 1 Endpoint 0 DPR Control USB Side SIE DPR Control mP side C51 Microcontroller Interface Up to 48 MHz UC_sysclk User DPRAM Figure 21-4. Minimum Intervention from the USB Device Firmware OUT Transactions: HOST UFI C51 OUT DATA0 (n bytes) OUT ACK DATA1 OUT interrupt C51 NACK DATA1 ACK Endpoint FIFO read (n bytes) IN Transactions: HOST UFI C51 21.2 21.2.1 IN IN NACK Endpoint FIFO write IN DATA1 ACK DATA1 interrupt C51 Endpoint FIFO write Configuration General Configuration • USB controller enable Before any USB transaction, the 48 MHz required by the USB controller must be correctly generated (See “Clock Controller” on page 13.). The USB controller will be then enabled by setting the EUSB bit in the USBCON register. • Set address After a Reset or a USB reset, the software has to set the FEN (Function Enable) bit in the USBADDR register. This action will allow the USB controller to answer to the requests sent at the address 0. When a SET_ADDRESS request has been received, the USB controller must only answer to the address defined by the request. The new address will be stored in the USBADDR register. The FEN bit and the FADDEN bit in the USBCON register will be set to allow the USB controller to answer only to requests sent at the new address. 103 7683C–USB–11/07 • Set configuration The CONFG bit in the USBCON register has to be set after a SET_CONFIGURATION request with a non-zero value. Otherwise, this bit has to be cleared. 21.2.2 Endpoint Configuration • Selection of an Endpoint The endpoint register access is performed using the UEPNUM register. The registers – UEPSTAX – UEPCONX – UEPDATX – UBYCTLX – UBYCTHX These registers correspond to the endpoint whose number is stored in the UEPNUM register. To select an Endpoint, the firmware has to write the endpoint number in the UEPNUM register. Figure 21-5. Endpoint Selection Endpoint 0 UEPSTA0 UEPCON0 UBYCTH0 UEPDAT0 0 SFR registers UBYCTL0 1 2 3 4 Endpoint 5 UEPSTA5 UEPCON5 UBYCTH5 UEPDAT5 X UEPSTAX UEPCONX UBYCTHX UEPDATX UBYCTLX 5 UBYCTL5 UEPNUM • Endpoint enable Before using an endpoint, this one will be enabled by setting the EPEN bit in the UEPCONX register. An endpoint which is not enabled won’t answer to any USB request. The Default Control Endpoint (Endpoint 0) will always be enabled in order to answer to USB standard requests. • Endpoint type configuration All Standard Endpoints can be configured in Control, Bulk, Interrupt or Isochronous mode. The Ping-pong Endpoints can be configured in Bulk, Interrupt or Isochronous mode. The configuration of an endpoint is performed by setting the field EPTYPE with the following values: – Control:EPTYPE = 00b – Isochronous:EPTYPE = 01b – Bulk:EPTYPE = 10b – Interrupt:EPTYPE = 11b 104 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 The Endpoint 0 is the Default Control Endpoint and will always be configured in Control type. • Endpoint direction configuration For Bulk, Interrupt and Isochronous endpoints, the direction is defined with the EPDIR bit of the UEPCONX register with the following values: – IN:EPDIR = 1b – OUT:EPDIR = 0b For Control endpoints, the EPDIR bit has no effect. • Summary of Endpoint Configuration: Do not forget to select the correct endpoint number in the UEPNUM register before accessing to endpoint specific registers. Table 21-1. Summary of Endpoint Configuration Endpoint Configuration EPEN EPDIR EPTYPE UEPCONX Disabled 0b Xb XXb 0XXX XXXb Control 1b Xb 00b 80h Bulk-in 1b 1b 10b 86h Bulk-out 1b 0b 10b 82h Interrupt-In 1b 1b 11b 87h Interrupt-Out 1b 0b 11b 83h Isochronous-In 1b 1b 01b 85h Isochronous-Out 1b 0b 01b 81h • Endpoint FIFO reset Before using an endpoint, its FIFO will be reset. This action resets the FIFO pointer to its original value, resets the byte counter of the endpoint (UBYCTLX and UBYCTHX registers), and resets the data toggle bit (DTGL bit in UEPCONX). The reset of an endpoint FIFO is performed by setting to 1 and resetting to 0 the corresponding bit in the UEPRST register. For example, in order to reset the Endpoint number 2 FIFO, write 0000 0100b then 0000 0000b in the UEPRST register. Note that the endpoint reset doesn’t reset the bank number for ping-pong endpoints. 21.3 21.3.1 Read/Write Data FIFO FIFO Mapping Depending on the selected endpoint through the UEPNUM register, the UEPDATX register allows to access the corresponding endpoint data fifo. 105 7683C–USB–11/07 Figure 21-6. Endpoint FIFO Configuration Endpoint 0 UEPSTA0 UEPCON0 UBYCTH0 UEPDAT0 0 SFR registers UBYCTL0 1 2 3 4 Endpoint 5 UEPSTA5 UEPCON5 UBYCTH5 UEPDAT5 X UEPSTAX UEPCONX UBYCTHX UEPDATX UBYCTLX 5 UBYCTL5 UEPNUM 21.3.2 Read Data FIFO The read access for each OUT endpoint is performed using the UEPDATX register. After a new valid packet has been received on an Endpoint, the data are stored into the FIFO and the byte counter of the endpoint is updated (UBYCTLX and UBYCTHX registers). The firmware has to store the endpoint byte counter before any access to the endpoint FIFO. The byte counter is not updated when reading the FIFO. To read data from an endpoint, select the correct endpoint number in UEPNUM and read the UEPDATX register. This action automatically decreases the corresponding address vector, and the next data is then available in the UEPDATX register. 21.3.3 Write Data FIFO The write access for each IN endpoint is performed using the UEPDATX register. To write a byte into an IN endpoint FIFO, select the correct endpoint number in UEPNUM and write into the UEPDATX register. The corresponding address vector is automatically increased, and another write can be carried out. Warning 1: The byte counter is not updated. Warning 2: Do not write more bytes than supported by the corresponding endpoint. 21.4 Bulk/Interrupt Transactions Bulk and Interrupt transactions are managed in the same way. 106 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 21.4.1 Bulk/Interrupt OUT Transactions in Standard Mode Figure 21-7. Bulk/Interrupt OUT transactions in Standard Mode HOST OUT C51 UFI DATA0 (n bytes) ACK RXOUTB0 Endpoint FIFO read byte 1 OUT DATA1 Endpoint FIFO read byte 2 NAK OUT Endpoint FIFO read byte n DATA1 Clear RXOUTB0 NAK OUT DATA1 ACK RXOUTB0 Endpoint FIFO read byte 1 An endpoint will be first enabled and configured before being able to receive Bulk or Interrupt packets. When a valid OUT packet is received on an endpoint, the RXOUTB0 bit is set by the USB controller. This triggers an interrupt if enabled. The firmware has to select the corresponding endpoint, store the number of data bytes by reading the UBYCTLX and UBYCTHX registers. If the received packet is a ZLP (Zero Length Packet), the UBYCTLX and UBYCTHX register values are equal to 0 and no data has to be read. When all the endpoint FIFO bytes have been read, the firmware will clear the RXOUTB0 bit to allow the USB controller to accept the next OUT packet on this endpoint. Until the RXOUTB0 bit has been cleared by the firmware, the USB controller will answer a NAK handshake for each OUT requests. If the Host sends more bytes than supported by the endpoint FIFO, the overflow data won’t be stored, but the USB controller will consider that the packet is valid if the CRC is correct and the endpoint byte counter contains the number of bytes sent by the Host. 107 7683C–USB–11/07 21.4.2 Bulk/Interrupt OUT Transactions in Ping-pong Mode Figure 21-8. Bulk/Interrupt OUT Transactions in Ping-pong Mode HOST OUT C51 UFI DATA0 (n Bytes) ACK RXOUTB0 Endpoint FIFO Bank 0 - Read Byte 1 OUT Endpoint FIFO Bank 0 - Read Byte 2 DATA1 (m Bytes) ACK Endpoint FIFO Bank 0 - Read Byte n Clear RXOUTB0 OUT RXOUTB1 DATA0 (p Bytes) Endpoint FIFO Bank 1 - Read Byte 1 ACK Endpoint FIFO Bank 1 - Read Byte 2 Endpoint FIFO Bank 1 - Read Byte m Clear RXOUTB1 RXOUTB0 Endpoint FIFO Bank 0 - Read Byte 1 Endpoint FIFO Bank 0 - Read Byte 2 Endpoint FIFO Bank 0 - Read Byte p Clear RXOUTB0 An endpoint will be first enabled and configured before being able to receive Bulk or Interrupt packets. When a valid OUT packet is received on the endpoint bank 0, the RXOUTB0 bit is set by the USB controller. This triggers an interrupt if enabled. The firmware has to select the corresponding endpoint, store the number of data bytes by reading the UBYCTLX and UBYCTHX registers. If the received packet is a ZLP (Zero Length Packet), the UBYCTLX and UBYCTHX register values are equal to 0 and no data has to be read. When all the endpoint FIFO bytes have been read, the firmware will clear the RXOUB0 bit to allow the USB controller to accept the next OUT packet on the endpoint bank 0. This action switches the endpoint bank 0 and 1. Until the RXOUTB0 bit has been cleared by the firmware, the USB controller will answer a NAK handshake for each OUT requests on the bank 0 endpoint FIFO. When a new valid OUT packet is received on the endpoint bank 1, the RXOUTB1 bit is set by the USB controller. This triggers an interrupt if enabled. The firmware empties the bank 1 endpoint FIFO before clearing the RXOUTB1 bit. Until the RXOUTB1 bit has been cleared by the firmware, the USB controller will answer a NAK handshake for each OUT requests on the bank 1 endpoint FIFO. The RXOUTB0 and RXOUTB1 bits are alternatively set by the USB controller at each new valid packet receipt. The firmware has to clear one of these two bits after having read all the data FIFO to allow a new valid packet to be stored in the corresponding bank. 108 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 A NAK handshake is sent by the USB controller only if the banks 0 and 1 has not been released by the firmware. If the Host sends more bytes than supported by the endpoint FIFO, the overflow data won’t be stored, but the USB controller will consider that the packet is valid if the CRC is correct. 21.4.3 Bulk/Interrupt IN Transactions in Standard Mode Figure 21-9. Bulk/Interrupt IN Transactions in Standard Mode UFI HOST C51 Endpoint FIFO Write Byte 1 IN Endpoint FIFO Write Byte 2 NAK Endpoint FIFO Write Byte n Set TXRDY IN DATA0 (n Bytes) ACK TXCMPL Clear TXCMPL Endpoint FIFO Write Byte 1 An endpoint will be first enabled and configured before being able to send Bulk or Interrupt packets. The firmware will fill the FIFO with the data to be sent and set the TXRDY bit in the UEPSTAX register to allow the USB controller to send the data stored in FIFO at the next IN request concerning this endpoint. To send a Zero Length Packet, the firmware will set the TXRDY bit without writing any data into the endpoint FIFO. Until the TXRDY bit has been set by the firmware, the USB controller will answer a NAK handshake for each IN requests. To cancel the sending of this packet, the firmware has to reset the TXRDY bit. The packet stored in the endpoint FIFO is then cleared and a new packet can be written and sent. When the IN packet has been sent and acknowledged by the Host, the TXCMPL bit in the UEPSTAX register is set by the USB controller. This triggers a USB interrupt if enabled. The firmware will clear the TXCMPL bit before filling the endpoint FIFO with new data. The firmware will never write more bytes than supported by the endpoint FIFO. All USB retry mechanisms are automatically managed by the USB controller. 109 7683C–USB–11/07 21.4.4 Bulk/Interrupt IN Transactions in Ping-pong Mode Figure 21-10. Bulk/Interrupt IN Transactions in Ping-pong Mode HOST C51 UFI Endpoint FIFO Bank 0 - Write Byte 1 IN Endpoint FIFO Bank 0 - Write Byte 2 NACK Endpoint FIFO Bank 0 - Write Byte n Set TXRDY IN Endpoint FIFO Bank 1 - Write Byte 1 DATA0 (n Bytes) Endpoint FIFO Bank 1 - Write Byte 2 ACK Endpoint FIFO Bank 1 - Write Byte m TXCMPL Clear TXCMPL Set TXRDY IN DATA1 (m Bytes) Endpoint FIFO Bank 0 - Write Byte 1 Endpoint FIFO Bank 0 - Write Byte 2 ACK Endpoint FIFO Bank 0 - Write Byte p TXCMPL Clear TXCMPL Set TXRDY IN DATA0 (p Bytes) Endpoint FIFO Bank 1 - Write Byte 1 ACK An endpoint will be first enabled and configured before being able to send Bulk or Interrupt packets. The firmware will fill the FIFO bank 0 with the data to be sent and set the TXRDY bit in the UEPSTAX register to allow the USB controller to send the data stored in FIFO at the next IN request concerning the endpoint. The FIFO banks are automatically switched, and the firmware can immediately write into the endpoint FIFO bank 1. When the IN packet concerning the bank 0 has been sent and acknowledged by the Host, the TXCMPL bit is set by the USB controller. This triggers a USB interrupt if enabled. The firmware will clear the TXCMPL bit before filling the endpoint FIFO bank 0 with new data. The FIFO banks are then automatically switched. When the IN packet concerning the bank 1 has been sent and acknowledged by the Host, the TXCMPL bit is set by the USB controller. This triggers a USB interrupt if enabled. The firmware will clear the TXCMPL bit before filling the endpoint FIFO bank 1 with new data. The bank switch is performed by the USB controller each time the TXRDY bit is set by the firmware. Until the TXRDY bit has been set by the firmware for an endpoint bank, the USB controller will answer a NAK handshake for each IN requests concerning this bank. Note that in the example above, the firmware clears the Transmit Complete bit (TXCMPL) before setting the Transmit Ready bit (TXRDY). This is done in order to avoid the firmware to clear at the same time the TXCMPL bit for bank 0 and the bank 1. 110 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 The firmware will never write more bytes than supported by the endpoint FIFO. 21.5 21.5.1 Control Transactions Setup Stage The DIR bit in the UEPSTAX register will be at 0. Receiving Setup packets is the same as receiving Bulk Out packets, except that the RXSETUP bit in the UEPSTAX register is set by the USB controller instead of the RXOUTB0 bit to indicate that an Out packet with a Setup PID has been received on the Control endpoint. When the RXSETUP bit has been set, all the other bits of the UEPSTAX register are cleared and an interrupt is triggered if enabled. The firmware has to read the Setup request stored in the Control endpoint FIFO before clearing the RXSETUP bit to free the endpoint FIFO for the next transaction. 21.5.2 Data Stage: Control Endpoint Direction The data stage management is similar to Bulk management. A Control endpoint is managed by the USB controller as a full-duplex endpoint: IN and OUT. All other endpoint types are managed as half-duplex endpoint: IN or OUT. The firmware has to specify the control endpoint direction for the data stage using the DIR bit in the UEPSTAX register. The firmware has to use the DIR bit before data IN in order to meet the data-toggle requirements: • If the data stage consists of INs, the firmware has to set the DIR bit in the UEPSTAX register before writing into the FIFO and sending the data by setting to 1 the TXRDY bit in the UEPSTAX register. The IN transaction is complete when the TXCMPL has been set by the hardware. The firmware will clear the TXCMPL bit before any other transaction. • If the data stage consists of OUTs, the firmware has to leave the DIR bit at 0. The RXOUTB0 bit is set by hardware when a new valid packet has been received on the endpoint. The firmware must read the data stored into the FIFO and then clear the RXOUTB0 bit to reset the FIFO and to allow the next transaction. To send a STALL handshake, see “STALL Handshake” on page 114. 21.5.3 Status Stage The DIR bit in the UEPSTAX register will be reset at 0 for IN and OUT status stage. The status stage management is similar to Bulk management. • For a Control Write transaction or a No-Data Control transaction, the status stage consists of a IN Zero Length Packet (see “Bulk/Interrupt IN Transactions in Standard Mode” on page 109). To send a STALL handshake, see “STALL Handshake” on page 114. • For a Control Read transaction, the status stage consists of a OUT Zero Length Packet (see “Bulk/Interrupt OUT Transactions in Standard Mode” on page 107). 111 7683C–USB–11/07 21.6 21.6.1 Isochronous Transactions Isochronous OUT Transactions in Standard Mode An endpoint will be first enabled and configured before being able to receive Isochronous packets. When a OUT packet is received on an endpoint, the RXOUTB0 bit is set by the USB controller. This triggers an interrupt if enabled. The firmware has to select the corresponding endpoint, store the number of data bytes by reading the UBYCTLX and UBYCTHX registers. If the received packet is a ZLP (Zero Length Packet), the UBYCTLX and UBYCTHX register values are equal to 0 and no data has to be read. The STLCRC bit in the UEPSTAX register is set by the USB controller if the packet stored in FIFO has a corrupted CRC. This bit is updated after each new packet receipt. When all the endpoint FIFO bytes have been read, the firmware will clear the RXOUTB0 bit to allow the USB controller to store the next OUT packet data into the endpoint FIFO. Until the RXOUTB0 bit has been cleared by the firmware, the data sent by the Host at each OUT transaction will be lost. If the RXOUTB0 bit is cleared while the Host is sending data, the USB controller will store only the remaining bytes into the FIFO. If the Host sends more bytes than supported by the endpoint FIFO, the overflow data won’t be stored, but the USB controller will consider that the packet is valid if the CRC is correct. 21.6.2 Isochronous OUT Transactions in Ping-pong Mode An endpoint will be first enabled and configured before being able to receive Isochronous packets. When a OUT packet is received on the endpoint bank 0, the RXOUTB0 bit is set by the USB controller. This triggers an interrupt if enabled. The firmware has to select the corresponding endpoint, store the number of data bytes by reading the UBYCTLX and UBYCTHX registers. If the received packet is a ZLP (Zero Length Packet), the UBYCTLX and UBYCTHX register values are equal to 0 and no data has to be read. The STLCRC bit in the UEPSTAX register is set by the USB controller if the packet stored in FIFO has a corrupted CRC. This bit is updated after each new packet receipt. When all the endpoint FIFO bytes have been read, the firmware will clear the RXOUB0 bit to allow the USB controller to store the next OUT packet data into the endpoint FIFO bank 0. This action switches the endpoint bank 0 and 1. Until the RXOUTB0 bit has been cleared by the firmware, the data sent by the Host on the bank 0 endpoint FIFO will be lost. If the RXOUTB0 bit is cleared while the Host is sending data on the endpoint bank 0, the USB controller will store only the remaining bytes into the FIFO. When a new OUT packet is received on the endpoint bank 1, the RXOUTB1 bit is set by the USB controller. This triggers an interrupt if enabled. The firmware empties the bank 1 endpoint FIFO before clearing the RXOUTB1 bit. Until the RXOUTB1 bit has been cleared by the firmware, the data sent by the Host on the bank 1 endpoint FIFO will be lost. The RXOUTB0 and RXOUTB1 bits are alternatively set by the USB controller at each new packet receipt. 112 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 The firmware has to clear one of these two bits after having read all the data FIFO to allow a new packet to be stored in the corresponding bank. If the Host sends more bytes than supported by the endpoint FIFO, the overflow data won’t be stored, but the USB controller will consider that the packet is valid if the CRC is correct. 21.6.3 Isochronous IN Transactions in Standard Mode An endpoint will be first enabled and configured before being able to send Isochronous packets. The firmware will fill the FIFO with the data to be sent and set the TXRDY bit in the UEPSTAX register to allow the USB controller to send the data stored in FIFO at the next IN request concerning this endpoint. If the TXRDY bit is not set when the IN request occurs, nothing will be sent by the USB controller. When the IN packet has been sent, the TXCMPL bit in the UEPSTAX register is set by the USB controller. This triggers a USB interrupt if enabled. The firmware will clear the TXCMPL bit before filling the endpoint FIFO with new data. The firmware will never write more bytes than supported by the endpoint FIFO 21.6.4 Isochronous IN Transactions in Ping-pong Mode An endpoint will be first enabled and configured before being able to send Isochronous packets. The firmware will fill the FIFO bank 0 with the data to be sent and set the TXRDY bit in the UEPSTAX register to allow the USB controller to send the data stored in FIFO at the next IN request concerning the endpoint. The FIFO banks are automatically switched, and the firmware can immediately write into the endpoint FIFO bank 1. If the TXRDY bit is not set when the IN request occurs, nothing will be sent by the USB controller. When the IN packet concerning the bank 0 has been sent, the TXCMPL bit is set by the USB controller. This triggers a USB interrupt if enabled. The firmware will clear the TXCMPL bit before filling the endpoint FIFO bank 0 with new data. The FIFO banks are then automatically switched. When the IN packet concerning the bank 1 has been sent, the TXCMPL bit is set by the USB controller. This triggers a USB interrupt if enabled. The firmware will clear the TXCMPL bit before filling the endpoint FIFO bank 1 with new data. The bank switch is performed by the USB controller each time the TXRDY bit is set by the firmware. Until the TXRDY bit has been set by the firmware for an endpoint bank, the USB controller won’t send anything at each IN requests concerning this bank. The firmware will never write more bytes than supported by the endpoint FIFO. 21.7 21.7.1 Miscellaneous USB Reset The EORINT bit in the USBINT register is set by hardware when a End Of Reset has been detected on the USB bus. This triggers a USB interrupt if enabled. The USB controller is still enabled, but all the USB registers are reset by hardware. The firmware will clear the EORINT bit to allow the next USB reset detection. 113 7683C–USB–11/07 21.7.2 STALL Handshake This function is only available for Control, Bulk, and Interrupt endpoints. The firmware has to set the STALLRQ bit in the UEPSTAX register to send a STALL handshake at the next request of the Host on the endpoint selected with the UEPNUM register. The RXSETUP, TXRDY, TXCMPL, RXOUTB0 and RXOUTB1 bits must be first reset to 0. The bit STLCRC is set at 1 by the USB controller when a STALL has been sent. This triggers an interrupt if enabled. The firmware will clear the STALLRQ and STLCRC bits after each STALL sent. The STALLRQ bit is cleared automatically by hardware when a valid SETUP PID is received on a CONTROL type endpoint. Important note: when a Clear Halt Feature occurs for an endpoint, the firmware will reset this endpoint using the UEPRST register in order to reset the data toggle management. 21.7.3 Start of Frame Detection The SOFINT bit in the USBINT register is set when the USB controller detects a Start of Frame PID. This triggers an interrupt if enabled. The firmware will clear the SOFINT bit to allow the next Start of Frame detection. 21.7.4 Frame Number When receiving a Start of Frame, the frame number is automatically stored in the UFNUML and UFNUMH registers. The CRCOK and CRCERR bits indicate if the CRC of the last Start of Frame is valid (CRCOK set at 1) or corrupted (CRCERR set at 1). The UFNUML and UFNUMH registers are automatically updated when receiving a new Start of Frame. 21.7.5 Data Toggle Bit The Data Toggle bit is set by hardware when a DATA0 packet is received and accepted by the USB controller and cleared by hardware when a DATA1 packet is received and accepted by the USB controller. This bit is reset when the firmware resets the endpoint FIFO using the UEPRST register. For Control endpoints, each SETUP transaction starts with a DATA0 and data toggling is then used as for Bulk endpoints until the end of the Data stage (for a control write transfer). The Status stage completes the data transfer with a DATA1 (for a control read transfer). For Isochronous endpoints, the device firmware will ignore the data-toggle. 21.8 21.8.1 Suspend/Resume Management Suspend The Suspend state can be detected by the USB controller if all the clocks are enabled and if the USB controller is enabled. The bit SPINT is set by hardware when an idle state is detected for more than 3 ms. This triggers a USB interrupt if enabled. In order to reduce current consumption, the firmware can put the USB PAD in idle mode, stop the clocks and put the C51 in Idle or Power-down mode. The Resume detection is still active. The USB PAD is put in idle mode when the firmware clear the SPINT bit. In order to avoid a new suspend detection 3ms later, the firmware has to disable the USB clock input using the SUSPCLK bit in the USBCON Register. The USB PAD automatically exits of idle mode when a wakeup event is detected. 114 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 The stop of the 48 MHz clock from the PLL should be done in the following order: 1. Clear suspend interrupt bit in USBINT (required to allow the USB pads to enter power down mode). 2. Enable USB resume interrupt. 3. Disable of the 48 MHz clock input of the USB controller by setting to 1 the SUSPCLK bit in the USBCON register. 4. Disable the PLL by clearing the PLLEN bit in the PLLCON register. 5. Make the CPU core enter power down mode by setting PDOWN bit in PCON. 21.8.2 Resume When the USB controller is in Suspend state, the Resume detection is active even if all the clocks are disabled and if the C51 is in Idle or Power-down mode. The WUPCPU bit is set by hardware when a non-idle state occurs on the USB bus. This triggers an interrupt if enabled. This interrupt wakes up the CPU from its Idle or Power-down state and the interrupt function is then executed. The firmware will first enable the 48 MHz generation and then reset to 0 the SUSPCLK bit in the USBCON register if needed. The firmware has to clear the SPINT bit in the USBINT register before any other USB operation in order to wake up the USB controller from its Suspend mode. The USB controller is then re-activated. Figure 21-11. Example of a Suspend/Resume Management USB Controller Init SPINT Detection of a SUSPEND State Clear SPINT Set SUSPCLK Disable PLL microcontroller in Power-down WUPCPU Detection of a RESUME State Enable PLL Clear SUSPCLK Clear WUPCPU Bit 115 7683C–USB–11/07 21.8.3 Upstream Resume A USB device can be allowed by the Host to send an upstream resume for Remote Wake Up purpose. When the USB controller receives the SET_FEATURE request: DEVICE_REMOTE_WAKEUP, the firmware will set to 1 the RMWUPE bit in the USBCON register to enable this functionality. RMWUPE value will be 0 in the other cases. If the device is in SUSPEND mode, the USB controller can send an upstream resume by clearing first the SPINT bit in the USBINT register and by setting then to 1 the SDRMWUP bit in the USBCON register. The USB controller sets to 1 the UPRSM bit in the USBCON register. All clocks must be enabled first. The Remote Wake is sent only if the USB bus was in Suspend state for at least 5 ms. When the upstream resume is completed, the UPRSM bit is reset to 0 by hardware. The firmware will then clear the SDRMWUP bit. Figure 21-12. Example of REMOTE WAKEUP Management USB Controller Init SET_FEATURE: DEVICE_REMOTE_WAKEUP Set RMWUPE SPINT Detection of a SUSPEND State Suspend Management Need USB Resume Enable Clocks Clear SPINT UPRSM = 1 Set SDMWUP UPRSM Upstream RESUME Sent Clear SDRMWUP 116 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 21.9 Detach Simulation In order to be re-enumerated by the Host, the AT83C5134/35/36 has the possibility to simulate a DETACH - ATTACH of the USB bus. The VREF output voltage is between 3.0V and 3.6V. This output can be connected to the D+ pullup as shown in Figure 21-13. This output can be put in high-impedance when the DETACH bit is set to 1 in the USBCON register. Maintaining this output in high impedance for more than 3 µs will simulate the disconnection of the device. When resetting the DETACH bit, an attach is then simulated. Figure 21-13. Example of VREF Connection VREF 1.5 kW 1 2 DD+ 3 4 AT89C5131 VCC DD+ GND USB-B Connector Figure 21-14. Disconnect Timing D+ VIHZ(min) VIL VSS D> = 2,5 ms Disconnect Detected Device Disconnected 21.10 USB Interrupt System 21.10.1 Interrupt System Priorities Figure 21-15. USB Interrupt Control System D+ D- 00 01 10 11 USB Controller EUSB EA IE1.6 IE0.7 Interrupt Enable IPH/L Priority Enable Lowest Priority Interrupts 117 7683C–USB–11/07 Table 21-2. 21.10.2 Priority Levels IPHUSB IPLUSB USB Priority Level 0 0 0 0 1 1 1 0 2 1 1 3 Lowest Highest USB Interrupt Control System As shown in Figure 21-16, many events can produce a USB interrupt: • TXCMPL: Transmitted In Data (see Table 21-9 on page 125). This bit is set by hardware when the Host accept a In packet. • RXOUTB0: Received Out Data Bank 0 (see Table 21-9 on page 125). This bit is set by hardware when an Out packet is accepted by the endpoint and stored in bank 0. • RXOUTB1: Received Out Data Bank 1 (only for Ping-pong endpoints) (see Table 21-9 on page 125). This bit is set by hardware when an Out packet is accepted by the endpoint and stored in bank 1. • RXSETUP: Received Setup (see Table 21-9 on page 125). This bit is set by hardware when an SETUP packet is accepted by the endpoint. • STLCRC: STALLED (only for Control, Bulk and Interrupt endpoints) (see Table 21-9 on page 125). This bit is set by hardware when a STALL handshake has been sent as requested by STALLRQ, and is reset by hardware when a SETUP packet is received. • SOFINT: Start of Frame Interrupt (See “USBIEN Register USBIEN (S:BEh) USB Global Interrupt Enable Register” on page 122.). This bit is set by hardware when a USB Start of Frame packet has been received. • WUPCPU: Wake-Up CPU Interrupt (See “USBIEN Register USBIEN (S:BEh) USB Global Interrupt Enable Register” on page 122.). This bit is set by hardware when a USB resume is detected on the USB bus, after a SUSPEND state. • SPINT: Suspend Interrupt (See “USBIEN Register USBIEN (S:BEh) USB Global Interrupt Enable Register” on page 122.). This bit is set by hardware when a USB suspend is detected on the USB bus. 118 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 Figure 21-16. USB Interrupt Control Block Diagram Endpoint X (X = 0..5) TXCMP UEPSTAX.0 RXOUTB0 UEPSTAX.1 EPXINT UEPINT.X RXOUTB1 UEPSTAX.6 EPXIE UEPIEN.X RXSETUP UEPSTAX.2 STLCRC UEPSTAX.3 WUPCPU USBINT.5 EWUPCPU USBIEN.5 EUSB IE1.6 EORINT USBINT.4 EEORINT USBIEN.4 SOFINT USBINT.3 ESOFINT USBIEN.3 SPINT USBINT.0 ESPINT USBIEN.0 119 7683C–USB–11/07 21.11 USB Registers Table 21-3. USBCON Register USBCON (S:BCh) USB Global Control Register 7 6 5 4 3 2 1 0 USBE SUSPCLK SDRMWUP DETACH UPRSM RMWUPE CONFG FADDEN Bit Number Bit Mnemonic 7 USBE 6 SUSPCLK 5 USB Enable Set this bit to enable the USB controller. Clear this bit to disable and reset the USB controller, to disable the USB transceiver an to disable the USB controller clock inputs. Suspend USB Clock Set this bit to disable the 48 MHz clock input (Resume Detection is still active). Clear this bit to enable the 48 MHz clock input. SDRMWUP Send Remote Wake Up Set this bit to force an external interrupt on the USB controller for Remote Wake UP purpose. An upstream resume is send only if the bit RMWUPE is set, all USB clocks are enabled AND the USB bus was in SUSPEND state for at least 5 ms. See UPRSM below. This bit is cleared by software. DETACH Detach Command Set this bit to simulate a Detach on the USB line. The VREF pin is then in a floating state. Clear this bit to maintain VREF at high level. UPRSM Upstream Resume (read only) This bit is set by hardware when SDRMWUP has been set and if RMWUPE is enabled. This bit is cleared by hardware after the upstream resume has been sent. 4 3 2 Description RMWUPE Remote Wake-Up Enable Set this bit to enabled request an upstream resume signaling to the host. Clear this bit otherwise. Note: Do not set this bit if the host has not set the DEVICE_REMOTE_WAKEUP feature for the device. 1 0 CONFG Configured This bit will be set by the device firmware after a SET_CONFIGURATION request with a non-zero value has been correctly processed. It will be cleared by the device firmware when a SET_CONFIGURATION request with a zero value is received. It is cleared by hardware on hardware reset or when an USB reset is detected on the bus (SE0 state for at least 32 Full Speed bit times: typically 2.7 µs). FADDEN Function Address Enable This bit will be set by the device firmware after a successful status phase of a SET_ADDRESS transaction. It will not be cleared afterwards by the device firmware. It is cleared by hardware on hardware reset or when an USB reset is received (see above). When this bit is cleared, the default function address is used (0). Reset Value = 00h 120 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 Table 21-4. USBINT Register USBINT (S:BDh) USB Global Interrupt Register 7 6 5 4 3 2 1 0 - - WUPCPU EORINT SOFINT - - SPINT Bit Number Bit Mnemonic Description 7-6 - 5 WUPCPU Reserved The value read from these bits is always 0. Do not set these bits. Wake Up CPU Interrupt This bit is set by hardware when the USB controller is in SUSPEND state and is reactivated by a non-idle signal FROM USB line (not by an upstream resume). This triggers a USB interrupt when EWUPCPU is set in Table 21-5 on page 122. When receiving this interrupt, user has to enable all USB clock inputs. This bit will be cleared by software (USB clocks must be enabled before). EORINT End Of Reset Interrupt This bit is set by hardware when a End Of Reset has been detected by the USB controller. This triggers a USB interrupt when EEORINT is set (see Figure 21-5 on page 122). This bit will be cleared by software. 3 SOFINT Start of Frame Interrupt This bit is set by hardware when an USB Start of Frame PID (SOF) has been detected. This triggers a USB interrupt when ESOFINT is set (see Table 21-5 on page 122). This bit will be cleared by software. 2 - Reserved The value read from this bit is always 0. Do not set this bit. 1 - Reserved The value read from this bit is always 0. Do not set this bit. 4 0 SPINT Suspend Interrupt This bit is set by hardware when a USB Suspend (Idle bus for three frame periods: a J state for 3 ms) is detected. This triggers a USB interrupt when ESPINT is set in see Table 21-5 on page 122. This bit will be cleared by software BEFORE any other USB operation to re-activate the macro. Reset Value = 00h 121 7683C–USB–11/07 Table 21-5. USBIEN Register USBIEN (S:BEh) USB Global Interrupt Enable Register 7 6 5 4 3 2 1 0 - - EWUPCPU EEORINT ESOFINT - - ESPINT Bit Number Bit Mnemonic 7-6 - 5 EWUPCPU Description Reserved The value read from these bits is always 0. Do not set these bits. Enable Wake Up CPU Interrupt Set this bit to enable Wake Up CPU Interrupt. (See “USBIEN Register USBIEN (S:BEh) USB Global Interrupt Enable Register” on page 122.) Clear this bit to disable Wake Up CPU Interrupt. EEOFINT Enable End Of Reset Interrupt Set this bit to enable End Of Reset Interrupt. (See “USBIEN Register USBIEN (S:BEh) USB Global Interrupt Enable Register” on page 122.). This bit is set after reset. Clear this bit to disable End Of Reset Interrupt. 3 ESOFINT Enable SOF Interrupt Set this bit to enable SOF Interrupt. (See “USBIEN Register USBIEN (S:BEh) USB Global Interrupt Enable Register” on page 122.). Clear this bit to disable SOF Interrupt. 2 - 1 - 4 0 ESPINT Reserved The value read from these bits is always 0. Do not set these bits. Enable Suspend Interrupt Set this bit to enable Suspend Interrupts (see the “USBIEN Register USBIEN (S:BEh) USB Global Interrupt Enable Register” on page 122). Clear this bit to disable Suspend Interrupts. Reset Value = 10h 122 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 Table 21-6. USBADDR Register USBADDR (S:C6h) USB Address Register 7 6 5 4 3 2 1 0 FEN UADD6 UADD5 UADD4 UADD3 UADD2 UADD1 UADD0 Bit Number Bit Mnemonic Description 7 FEN 6-0 UADD[6:0] Function Enable Set this bit to enable the address filtering function. Cleared this bit to disable the function. USB Address This field contains the default address (0) after power-up or USB bus reset. It will be written with the value set by a SET_ADDRESS request received by the device firmware. Reset Value = 80h Table 21-7. UEPNUM Register UEPNUM (S:C7h) USB Endpoint Number 7 6 5 4 3 2 1 0 - - - - EPNUM3 EPNUM2 EPNUM1 EPNUM0 Bit Number Bit Mnemonic 7-4 - 3-0 EPNUM[3:0] Description Reserved The value read from these bits is always 0. Do not set these bits. Endpoint Number Set this field with the number of the endpoint which will be accessed when reading or writing to, UEPDATX Register UEPDATX (S:CFh) USB FIFO Data Endpoint X (X = EPNUM set in UEPNUM Register UEPNUM (S:C7h) USB Endpoint Number), UBYCTLX Register UBYCTLX (S:E2h) USB Byte Count Low Register X (X = EPNUM set in UEPNUM Register UEPNUM (S:C7h) USB Endpoint Number), UBYCTHX Register UBYCTHX (S:E3h) USB Byte Count High Register X (X = EPNUM set in UEPNUM Register UEPNUM (S:C7h) USB Endpoint Number) or UEPCONX Register UEPCONX (S:D4h) USB Endpoint X Control Register. This value can be 0, 1, 2, 3, 4, or 5. Reset Value = 00h 123 7683C–USB–11/07 Table 21-8. UEPCONX Register UEPCONX (S:D4h) USB Endpoint X Control Register 7 6 5 4 3 2 1 0 EPEN - - - DTGL EPDIR EPTYPE1 EPTYPE0 Bit Number Endpoint Enable Set this bit to enable the endpoint according to the device configuration. Endpoint 0 will always be enabled after a hardware or USB bus reset and participate in the device configuration. Clear this bit to disable the endpoint according to the device configuration. 7 EPEN 6 - Reserved The value read from this bit is always 0. Do not set this bit. 5 - Reserved The value read from this bit is always 0. Do not set this bit. 4 - Reserved The value read from this bit is always 0. Do not set this bit. 3 DTGL Data Toggle (Read-only) This bit is set by hardware when a valid DATA0 packet is received and accepted. This bit is cleared by hardware when a valid DATA1 packet is received and accepted. EPDIR Endpoint Direction Set this bit to configure IN direction for Bulk, Interrupt and Isochronous endpoints. Clear this bit to configure OUT direction for Bulk, Interrupt and Isochronous endpoints. This bit has no effect for Control endpoints. 2 1-0 Note: Bit Mnemonic Description EPTYPE[1:0] Endpoint Type Set this field according to the endpoint configuration (Endpoint 0 will always be configured as control): 00Control endpoint 01Isochronous endpoint 10Bulk endpoint 11Interrupt endpoint 1. (X = EPNUM set in UEPNUM Register UEPNUM (S:C7h) USB Endpoint Number) Reset Value = 80h when UEPNUM = 0 (default Control Endpoint) Reset Value = 00h otherwise for all other endpoints 124 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 Table 21-9. UEPSTAX (S:CEh) USB Endpoint X Status Register 7 6 5 4 3 2 1 0 DIR RXOUTB1 STALLRQ TXRDY STL/CRC RXSETUP RXOUTB0 TXCMP Bit Number Bit Mnemonic Description DIR Control Endpoint Direction This bit is used only if the endpoint is configured in the control type (seeSection “UEPCONX Register UEPCONX (S:D4h) USB Endpoint X Control Register”). This bit determines the Control data and status direction. The device firmware will set this bit ONLY for the IN data stage, before any other USB operation. Otherwise, the device firmware will clear this bit. 6 RXOUTB1 Received OUT Data Bank 1 for Endpoints 4, 5 and 6 (Ping-pong mode) This bit is set by hardware after a new packet has been stored in the endpoint FIFO data bank 1 (only in Ping-pong mode). Then, the endpoint interrupt is triggered if enabled (see“UEPINT Register UEPINT (S:F8h read-only) USB Endpoint Interrupt Register” on page 128) and all the following OUT packets to the endpoint bank 1 are rejected (NAK’ed) until this bit has been cleared, excepted for Isochronous Endpoints. This bit will be cleared by the device firmware after reading the OUT data from the endpoint FIFO. 5 STALLRQ Stall Handshake Request Set this bit to request a STALL answer to the host for the next handshake.Clear this bit otherwise. For CONTROL endpoints: cleared by hardware when a valid SETUP PID is received. 7 4 3 2 1 0 TXRDY TX Packet Ready Set this bit after a packet has been written into the endpoint FIFO for IN data transfers. Data will be written into the endpoint FIFO only after this bit has been cleared. Set this bit without writing data to the endpoint FIFO to send a Zero Length Packet. This bit is cleared by hardware, as soon as the packet has been sent for Isochronous endpoints, or after the host has acknowledged the packet for Control, Bulk and Interrupt endpoints. When this bit is cleared, the endpoint interrupt is triggered if enabled (see“UEPINT Register UEPINT (S:F8h read-only) USB Endpoint Interrupt Register” on page 128). STLCRC Stall Sent/CRC error flag - For Control, Bulk and Interrupt Endpoints: This bit is set by hardware after a STALL handshake has been sent as requested by STALLRQ. Then, the endpoint interrupt is triggered if enabled (see“UEPINT Register UEPINT (S:F8h read-only) USB Endpoint Interrupt Register” on page 128) It will be cleared by the device firmware. - For Isochronous Endpoints (Read-Only): This bit is set by hardware if the last received data is corrupted (CRC error on data). This bit is updated by hardware when a new data is received. RXSETUP Received SETUP This bit is set by hardware when a valid SETUP packet has been received from the host. Then, all the other bits of the register are cleared by hardware and the endpoint interrupt is triggered if enabled (see“UEPINT Register UEPINT (S:F8h read-only) USB Endpoint Interrupt Register” on page 128). It will be cleared by the device firmware after reading the SETUP data from the endpoint FIFO. RXOUTB0 Received OUT Data Bank 0 (see also RXOUTB1 bit for Ping-pong Endpoints) This bit is set by hardware after a new packet has been stored in the endpoint FIFO data bank 0. Then, the endpoint interrupt is triggered if enabled (see“UEPINT Register UEPINT (S:F8h read-only) USB Endpoint Interrupt Register” on page 128) and all the following OUT packets to the endpoint bank 0 are rejected (NAK’ed) until this bit has been cleared, excepted for Isochronous Endpoints. However, for control endpoints, an early SETUP transaction may overwrite the content of the endpoint FIFO, even if its Data packet is received while this bit is set. This bit will be cleared by the device firmware after reading the OUT data from the endpoint FIFO. TXCMPL Transmitted IN Data Complete This bit is set by hardware after an IN packet has been transmitted for Isochronous endpoints and after it has been accepted (ACK’ed) by the host for Control, Bulk and Interrupt endpoints. Then, the endpoint interrupt is triggered if enabled (see“UEPINT Register UEPINT (S:F8h read-only) USB Endpoint Interrupt Register” on page 128). This bit will be cleared by the device firmware before setting TXRDY. Reset Value = 00h 125 7683C–USB–11/07 Table 21-10. UEPDATX Register UEPDATX (S:CFh) USB FIFO Data Endpoint X (X = EPNUM set in UEPNUM Register UEPNUM (S:C7h) USB Endpoint Number) 7 6 5 4 3 2 1 0 FDAT7 FDAT6 FDAT5 FDAT4 FDAT3 FDAT2 FDAT1 FDAT0 Bit Number Bit Mnemonic 7-0 FDAT[7:0] Description Endpoint X FIFO data Data byte to be written to FIFO or data byte to be read from the FIFO, for the Endpoint X (see EPNUM). Reset Value = XXh Table 21-11. UBYCTLX Register UBYCTLX (S:E2h) USB Byte Count Low Register X (X = EPNUM set in UEPNUM Register UEPNUM (S:C7h) USB Endpoint Number) 7 6 5 4 3 2 1 0 BYCT7 BYCT6 BYCT5 BYCT4 BYCT3 BYCT2 BYCT1 BYCT0 Bit Number Bit Mnemonic 7-0 BYCT[7:0] Description Byte Count LSB Least Significant Byte of the byte count of a received data packet. The most significant part is provided by the UBYCTHX Register UBYCTHX (S:E3h) USB Byte Count High Register X (X = EPNUM set in UEPNUM Register UEPNUM (S:C7h) USB Endpoint Number) (see Figure 21-11 on page 126). This byte count is equal to the number of data bytes received after the Data PID. Reset Value = 00h Table 21-12. UBYCTHX Register UBYCTHX (S:E3h) USB Byte Count High Register X (X = EPNUM set in UEPNUM Register UEPNUM (S:C7h) USB Endpoint Number) 7 6 5 4 3 2 1 0 - - - - - - BYCT9 BYCT8 Bit Number Bit Mnemonic 7-2 - 2-0 Description Reserved The value read from these bits is always 0. Do not set these bits. BYCT[10:8] Byte Count MSB Most Significant Byte of the byte count of a received data packet. The Least significant part is provided by UBYCTLX Register UBYCTLX (S:E2h) USB Byte Count Low Register X (X = EPNUM set in UEPNUM Register UEPNUM (S:C7h) USB Endpoint Number) (see Figure 21-11 on page 126). Reset Value = 00h 126 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 Table 21-13. UEPRST Register UEPRST (S:D5h) USB Endpoint FIFO Reset Register 7 6 5 4 3 2 1 0 - - EP5RST EP4RST EP3RST EP2RST EP1RST EP0RST Bit Number Bit Mnemonic Description 7 - Reserved The value read from this bit is always 0. Do not set this bit. 6 - Reserved The value read from this bit is always 0. Do not set this bit. 5 4 3 2 1 0 EP5RST Endpoint 5 FIFO Reset Set this bit and reset the endpoint FIFO prior to any other operation, upon hardware reset or when an USB bus reset has been received. Then, clear this bit to complete the reset operation and start using the FIFO. EP4RST Endpoint 4 FIFO Reset Set this bit and reset the endpoint FIFO prior to any other operation, upon hardware reset or when an USB bus reset has been received. Then, clear this bit to complete the reset operation and start using the FIFO. EP3RST Endpoint 3 FIFO Reset Set this bit and reset the endpoint FIFO prior to any other operation, upon hardware reset or when an USB bus reset has been received. Then, clear this bit to complete the reset operation and start using the FIFO. EP2RST Endpoint 2 FIFO Reset Set this bit and reset the endpoint FIFO prior to any other operation, upon hardware reset or when an USB bus reset has been received. Then, clear this bit to complete the reset operation and start using the FIFO. EP1RST Endpoint 1 FIFO Reset Set this bit and reset the endpoint FIFO prior to any other operation, upon hardware reset or when an USB bus reset has been received. Then, clear this bit to complete the reset operation and start using the FIFO. EP0RST Endpoint 0 FIFO Reset Set this bit and reset the endpoint FIFO prior to any other operation, upon hardware reset or when an USB bus reset has been received. Then, clear this bit to complete the reset operation and start using the FIFO. Reset Value = 00h 127 7683C–USB–11/07 Table 21-14. UEPINT Register UEPINT (S:F8h read-only) USB Endpoint Interrupt Register 7 6 5 4 3 2 1 0 - - EP5INT EP4INT EP3INT EP2INT EP1INT EP0INT Bit Number Bit Mnemonic Description 7 - Reserved The value read from this bit is always 0. Do not set this bit. 6 - Reserved The value read from this bit is always 0. Do not set this bit. Endpoint 5 Interrupt 5 EP5INT This bit is set by hardware when an endpoint interrupt source has been detected on the endpoint 5. The endpoint interrupt sources are in the UEPSTAX register and can be: TXCMP, RXOUTB0, RXOUTB1, RXSETUP or STLCRC. A USB interrupt is triggered when the EP5IE bit in the UEPIEN register is set. This bit is cleared by hardware when all the endpoint interrupt sources are cleared Endpoint 4 Interrupt 4 EP4INT This bit is set by hardware when an endpoint interrupt source has been detected on the endpoint 4. The endpoint interrupt sources are in the UEPSTAX register and can be: TXCMP, RXOUTB0, RXOUTB1, RXSETUP or STLCRC. A USB interrupt is triggered when the EP4IE bit in the UEPIEN register is set. This bit is cleared by hardware when all the endpoint interrupt sources are cleared Endpoint 3 Interrupt 3 EP3INT This bit is set by hardware when an endpoint interrupt source has been detected on the endpoint 3. The endpoint interrupt sources are in the UEPSTAX register and can be: TXCMP, RXOUTB0, RXOUTB1, RXSETUP or STLCRC. A USB interrupt is triggered when the EP3IE bit in the UEPIEN register is set. This bit is cleared by hardware when all the endpoint interrupt sources are cleared Endpoint 2 Interrupt 2 EP2INT This bit is set by hardware when an endpoint interrupt source has been detected on the endpoint 2. The endpoint interrupt sources are in the UEPSTAX register and can be: TXCMP, RXOUTB0, RXOUTB1, RXSETUP or STLCRC. A USB interrupt is triggered when the EP2IE bit in the UEPIEN register is set. This bit is cleared by hardware when all the endpoint interrupt sources are cleared Endpoint 1 Interrupt 1 EP1INT This bit is set by hardware when an endpoint interrupt source has been detected on the endpoint 1. The endpoint interrupt sources are in the UEPSTAX register and can be: TXCMP, RXOUTB0, RXOUTB1, RXSETUP or STLCRC. A USB interrupt is triggered when the EP1IE bit in the UEPIEN register is set. This bit is cleared by hardware when all the endpoint interrupt sources are cleared Endpoint 0 Interrupt 0 EP0INT This bit is set by hardware when an endpoint interrupt source has been detected on the endpoint 0. The endpoint interrupt sources are in the UEPSTAX register and can be: TXCMP, RXOUTB0, RXOUTB1, RXSETUP or STLCRC. A USB interrupt is triggered when the EP0IE bit in the UEPIEN register is set. This bit is cleared by hardware when all the endpoint interrupt sources are cleared Reset Value = 00h 128 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 Table 21-15. UEPIEN Register UEPIEN (S:C2h) USB Endpoint Interrupt Enable Register 7 6 5 4 3 2 1 0 - - EP5INTE EP4INTE EP3INTE EP2INTE EP1INTE EP0INTE Bit Number Bit Mnemonic Description 7 - Reserved The value read from this bit is always 0. Do not set this bit. 6 - Reserved The value read from this bit is always 0. Do not set this bit. 5 EP5INTE Endpoint 5 Interrupt Enable Set this bit to enable the interrupts for this endpoint. Clear this bit to disable the interrupts for this endpoint. 4 EP4INTE Endpoint 4 Interrupt Enable Set this bit to enable the interrupts for this endpoint. Clear this bit to disable the interrupts for this endpoint. 3 EP3INTE Endpoint 3 Interrupt Enable Set this bit to enable the interrupts for this endpoint. Clear this bit to disable the interrupts for this endpoint. 2 EP2INTE Endpoint 2 Interrupt Enable Set this bit to enable the interrupts for this endpoint. Clear this bit to disable the interrupts for this endpoint. 1 EP1INTE Endpoint 1 Interrupt Enable Set this bit to enable the interrupts for this endpoint. Clear this bit to disable the interrupts for this endpoint. 0 EP0INTE Endpoint 0 Interrupt Enable Set this bit to enable the interrupts for this endpoint. Clear this bit to disable the interrupts for this endpoint. Reset Value = 00h 129 7683C–USB–11/07 Table 21-16. UFNUMH Register UFNUMH (S:BBh, read-only) USB Frame Number High Register 7 6 5 4 3 2 1 0 - - CRCOK CRCERR - FNUM10 FNUM9 FNUM8 Bit Number 5 Bit Mnemonic Description CRCOK 4 CRCERR 3 - 2-0 Frame Number CRC OK This bit is set by hardware when a new Frame Number in Start of Frame Packet is received without CRC error. This bit is updated after every Start of Frame packet receipt. Important note: the Start of Frame interrupt is generated just after the PID receipt. Frame Number CRC Error This bit is set by hardware when a corrupted Frame Number in Start of Frame packet is received. This bit is updated after every Start of Frame packet receipt. Important note: the Start of Frame interrupt is generated just after the PID receipt. Reserved The value read from this bit is always 0. Do not set this bit. FNUM[10:8] Frame Number FNUM[10:8] are the upper 3 bits of the 11-bit Frame Number (see the “UFNUML Register UFNUML (S:BAh, read-only) USB Frame Number Low Register” on page 130). It is provided in the last received SOF packet (see SOFINT in the “USBIEN Register USBIEN (S:BEh) USB Global Interrupt Enable Register” on page 122). FNUM is updated if a corrupted SOF is received. Reset Value = 00h Table 21-17. UFNUML Register UFNUML (S:BAh, read-only) USB Frame Number Low Register 7 6 5 4 3 2 1 0 FNUM7 FNUM6 FNUM5 FNUM4 FNUM3 FNUM2 FNUM1 FNUM0 Bit Number Bit Mnemonic Description 7-0 FNUM[7:0] Frame Number FNUM[7:0] are the lower 8 bits of the 11-bit Frame Number (See “UFNUMH Register UFNUMH (S:BBh, read-only) USB Frame Number High Register” on page 130.). Reset Value = 00h 130 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 22. Reset 22.1 Introduction The reset sources are: Power Management, Hardware Watchdog, PCA Watchdog and Reset input. Figure 22-1. Reset schematic Power Monitor Hardware Watchdog Internal Reset PCA Watchdog RST 22.2 Reset Input The Reset input can be used to force a reset pulse longer than the internal reset controlled by the Power Monitor. RST input has a pull-up resistor allowing power-on reset by simply connecting an external capacitor to V S S as shown in Figure 22-2. Resistor value and input characteristics are discussed in the Section “DC Characteristics” of the AT83C5134/35/36 datasheet. Figure 22-2. Reset Circuitry and Power-On Reset VCC RST RRST + RST To internal reset a. RST input circuitry 22.3 VSS b. Power-on Reset Reset Output As detailed in Section “Hardware Watchdog Timer”, page 138, 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 Figure 22-3. 131 7683C–USB–11/07 Figure 22-3. Recommended Reset Output Schematic VDD RST RST 1K AT89C5131A-M VSS + VSS 132 To other on-board circuitry AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 23. Power Monitor The POR/PFD function monitors the internal power-supply of the CPU core memories and the peripherals, and if needed, suspends their activity when the internal power supply falls below a safety threshold. This is achieved by applying an internal reset to them. By generating the Reset the Power Monitor insures a correct start up when AT89C5131 is powered up. 23.1 Description In order to startup and maintain the microcontroller in correct operating mode, VCC has to be stabilized in the VCC operating range and the oscillator has to be stabilized with a nominal amplitude compatible with logic level VIH/VIL. These parameters are controlled during the three phases: power-up, normal operation and power going down. See Figure 23-1. Figure 23-1. Power Monitor Block Diagram VCC CPU core Power On Reset Power Fail Detect Voltage Regulator Regulated Supply Memories Peripherals (1) XTAL1 Internal Reset RST pin PCA Watchdog Note: Hardware Watchdog 1. Once XTAL1 High and low levels reach above and below VIH/VIL. a 1024 clock period delay will extend the reset coming from the Power Fail Detect. If the power falls below the Power Fail Detect threshold level, the Reset will be applied immediately. The Voltage regulator generates a regulated internal supply for the CPU core the memories and the peripherals. Spikes on the external Vcc are smoothed by the voltage regulator. The Power fail detect monitor the supply generated by the voltage regulator and generate a reset if this supply falls below a safety threshold as illustrated in the Figure 23-2 below. 133 7683C–USB–11/07 Figure 23-2. Power Fail Detect Vcc t Reset Vcc When the power is applied, the Power Monitor immediately asserts a reset. Once the internal supply after the voltage regulator reach a safety level, the power monitor then looks at the XTAL clock input. The internal reset will remain asserted until the Xtal1 levels are above and below VIH and VIL. Further more. An internal counter will count 1024 clock periods before the reset is de-asserted. If the internal power supply falls below a safety level, a reset is immediately asserted. . 134 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 24. Power Management 24.1 Idle Mode An instruction that sets PCON.0 indicates that it is the last instruction to be executed before going into the Idle mode. In the Idle mode, the internal clock signal is gated off to the CPU, but not to the interrupt, Timer, and Serial Port functions. The CPU status is preserved in its entirety: the Stack Pointer, Program Counter, Program Status Word, Accumulator and all other registers maintain their data during Idle. The port pins hold the logical states they had at the time Idle was activated. ALE and PSEN hold at logic high level. There are two ways to terminate the Idle mode. Activation of any enabled interrupt will cause PCON.0 to be cleared by hardware, terminating the Idle mode. The interrupt will be serviced, and following RETI the next instruction to be executed will be the one following the instruction that put the device into idle. The flag bits GF0 and GF1 can be used to give an indication if an interrupt occurred during normal operation or during an Idle. For example, an instruction that activates Idle can also set one or both flag bits. When Idle is terminated by an interrupt, the interrupt service routine can examine the flag bits. The other way of terminating the Idle mode is with a hardware reset. Since the clock oscillator is still running, the hardware reset needs to be held active for only two machine cycles (24 oscillator periods) to complete the reset. 24.2 Power-down Mode To save maximum power, a power-down mode can be invoked by software (refer to Table 13, PCON register). In power-down mode, the oscillator is stopped and the instruction that invoked power-down mode is the last instruction executed. The internal RAM and SFRs retain their value until the power-down mode is terminated. VCC can be lowered to save further power. Either a hardware reset or an external interrupt can cause an exit from power-down. To properly terminate powerdown, the reset or external interrupt should not be executed before VCC is restored to its normal operating level and must be held active long enough for the oscillator to restart and stabilize. Only: • external interrupt INT0, • external interrupt INT1, • Keyboard interrupt and • USB Interrupt are useful to exit from power-down. For that, interrupt must be enabled and configured as level or edge sensitive interrupt input. When Keyboard Interrupt occurs after a power down mode, 1024 clocks are necessary to exit to power-down mode and enter in operating mode. Holding the pin low restarts the oscillator but bringing the pin high completes the exit as detailed in Figure 24-1. When both interrupts are enabled, the oscillator restarts as soon as one of the two inputs is held low and power-down exit will be completed when the first input is released. In this case, the higher priority interrupt service routine is executed. Once the interrupt is serviced, the next instruction to be executed after RETI will be the one following the instruction that put AT83C5134/35/36 into power-down mode. 135 7683C–USB–11/07 Figure 24-1. Power-down Exit Waveform INT0 INT1 XTAL Active Phase Power-down Phase Oscillator restart Phase Active Phase Exit from power-down by reset redefines all the SFRs, exit from power-down by external interrupt does no affect the SFRs. Exit from power-down by either reset or external interrupt does not affect the internal RAM content. Note: If idle mode is activated with power-down mode (IDL and PD bits set), the exit sequence is unchanged, when execution is vectored to interrupt, PD and IDL bits are cleared and idle mode is not entered. This table shows the state of ports during idle and power-down modes. Table 24-1. Mode Program Memory ALE PSEN PORT0 PORT1 PORT2 PORT3 PORTI2 Idle Internal 1 1 Port Data(1) Port Data Port Data Port Data Port Data Idle External 1 1 Floating Port Data Address Port Data Port Data Power-down Internal 0 0 Port Data(1) Port Data Port Data Port Data Port Data Power-down External 0 0 Floating Port Data Port Data Port Data Port Data Note: 136 State of Ports 1. Port 0 can force a 0 level. A “one” will leave port floating. AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 24.3 Registers Table 24-2. PCON Register PCON (S:87h) Power Control Register 7 6 5 4 3 2 1 0 SMOD1 SMOD0 - POF GF1 GF0 PD IDL Bit Number Bit Mnemonic Description 7 SMOD1 Serial Port Mode bit 1 Set to select double baud rate in mode 1, 2 or 3. 6 SMOD0 Serial Port Mode bit 0 Set to select FE bit in SCON register. Clear to select SM0 bit in SCON register 5 - Reserved The value read from this bit is always 0. Do not set this bit. 4 POF Power-Off Flag Set by hardware when VCC rises from 0 to its nominal voltage. Can also be set by software. Clear to recognize next reset type. 3 GF1 General-purpose Flag 1 Set by software for general-purpose usage. Cleared by software for general-purpose usage. 2 GF0 General-purpose Flag 0 Set by software for general-purpose usage. Cleared by software for general-purpose usage. 1 PD Power-down mode bit Set this bit to enter in power-down mode. Cleared by hardware when reset occurs. 0 IDL Idle mode bit Set this bit to enter in Idle mode. Cleared by hardware when interrupt or reset occurs. Reset Value = 10h 137 7683C–USB–11/07 25. Hardware Watchdog Timer The WDT is intended as a recovery method in situations where the CPU may be subjected to software upset. The WDT consists of a 14-bit counter and the WatchDog Timer ReSeT (WDTRST) SFR. The WDT is by default disabled from exiting reset. To enable the WDT, user must write 01EH and 0E1H in sequence to the WDTRST, SFR location 0A6H. When WDT is enabled, it will increment every machine cycle while the oscillator is running and there is no way to disable the WDT except through reset (either hardware reset or WDT overflow reset). When WDT overflows, it will drive an output RESET LOW pulse at the RST-pin. 25.1 Using the WDT To enable the WDT, user must write 01EH and 0E1H in sequence to the WDTRST, SFR location 0A6H. When WDT is enabled, the user needs to service it by writing to 01EH and 0E1H to WDTRST to avoid WDT overflow. The 14-bit counter overflows when it reaches 16383 (3FFFH) and this will reset the device. When WDT is enabled, it will increment every machine cycle while the oscillator is running. This means the user must reset the WDT at least every 16383 machine cycle. To reset the WDT the user must write 01EH and 0E1H to WDTRST. WDTRST is a write only register. The WDT counter cannot be read or written. When WDT overflows, it will generate an output RESET pulse at the RST-pin. The RESET pulse duration is 96 x TCLK PERIPH, where TCLK PERIPH = 1/FCLK PERIPH. To make the best use of the WDT, it should be serviced in those sections of code that will periodically be executed within the time required to prevent a WDT reset. To have a more powerful WDT, a 27 counter has been added to extend the Time-out capability, ranking from 16 ms to 2s at FOSCA = 12 MHz. To manage this feature, refer to WDTPRG register description, Table 25-2. Table 25-1. WDTRST Register WDTRST - Watchdog Reset Register (0A6h) 7 6 5 4 3 2 1 0 - - - - - - - - Reset Value = XXXX XXXXb Write only, this SFR is used to reset/enable the WDT by writing 01EH then 0E1H in sequence. 138 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 Table 25-2. WDTPRG Register WDTPRG - Watchdog Timer Out Register (0A7h) 7 6 5 4 3 2 1 0 - - - - - S2 S1 S0 Bit Bit Number Mnemonic 7 - 6 - 5 - 4 - 3 - 2 S2 WDT Time-out select bit 2 1 S1 WDT Time-out select bit 1 0 S0 WDT Time-out select bit 0 Description Reserved The value read from this bit is undetermined. Do not try to set this bit. S2 S1 S0 Selected Time-out 0 0 0 16384x2^(214 - 1) machine cycles, 16.3 ms at FOSC = 12 MHz 0 0 1 16384x2^(215 - 1) machine cycles, 32.7 ms at FOSC = 12 MHz 0 1 0 16384x2^(216 - 1) machine cycles, 65.5 ms at FOSC = 12 MHz 0 1 1 16384x2^(217 - 1) machine cycles, 131 ms at FOSC = 12 MHz 1 0 0 16384x2^(218 - 1) machine cycles, 262 ms at FOSC = 12 MHz 1 0 1 16384x2^(219 - 1) machine cycles, 542 ms at FOSC = 12 MHz 1 1 0 16384x2^(220 - 1) machine cycles, 1.05 s at FOSC = 12 MHz 1 1 1 16384x2^(221 - 1) machine cycles, 2.09 s at FOSC = 12 MHz 16384x2^S machine cycles Reset value = XXXX X000 25.2 WDT During Power-down and Idle In Power-down mode the oscillator stops, which means the WDT also stops. While in Powerdown mode the user does not need to service the WDT. There are 2 methods of exiting Powerdown mode: by a hardware reset or via a level activated external interrupt which is enabled prior to entering Power-down mode. When Power-down is exited with hardware reset, servicing the WDT should occur as it normally should whenever the AT83C5134/35/36 is reset. Exiting Power-down with an interrupt is significantly different. The interrupt is held low long enough for the oscillator to stabilize. When the interrupt is brought high, the interrupt is serviced. To prevent the WDT from resetting the device while the interrupt pin is held low, the WDT is not started until the interrupt is pulled high. It is suggested that the WDT be reset during the interrupt service routine. To ensure that the WDT does not overflow within a few states of exiting of power-down, it is better to reset the WDT just before entering power-down. In the Idle mode, the oscillator continues to run. To prevent the WDT from resetting the AT83C5134/35/36 while in Idle mode, the user should always set up a timer that will periodically exit Idle, service the WDT, and re-enter Idle mode. 139 7683C–USB–11/07 AT83C5134/35/36 26. Reduced EMI Mode The ALE signal is used to demultiplex address and data buses on port 0 when used with external program or data memory. Nevertheless, during internal code execution, ALE signal is still generated. In order to reduce EMI, ALE signal can be disabled by setting AO bit. The AO bit is located in AUXR register at bit location 0. As soon as AO is set, ALE is no longer output but remains active during MOVX and MOVC instructions and external fetches. During ALE disabling, ALE pin is weakly pulled high. Table 26-1. AUXR Register AUXR - Auxiliary Register (8Eh) 7 6 5 4 3 2 1 0 DPU - M0 - XRS1 XRS0 EXTRAM AO Bit Bit Number Mnemonic 7 DPU 6 - Description Disable Weak Pull Up Cleared to enabled weak pull up on standard Ports Set to disable weak pull up on standard Ports Reserved The value read from this bit is indeterminate. Do not set this bit. Pulse length 5 M0 Cleared to stretch MOVX control: the RD and the WR pulse length is 6 clock periods (default). Set to stretch MOVX control: the RD and the WR pulse length is 30 clock periods. Reserved 4 - 3 XRS1 ERAM Size 2 XRS0 XRS1 0 0 1 1 1 EXTRAM The value read from this bit is indeterminate. Do not set this bit. XRS0 0 1 0 1 ERAM size 256 bytes 512 bytes 768 bytes 1024 bytes (default) EXTRAM bit Cleared to access internal ERAM using MOVX at Ri at DPTR. Set to access external memory. 0 AO ALE Output bit Cleared, ALE is emitted at a constant rate of 1/6 the oscillator frequency (or 1/3 if X2 mode is used) (default). Set, ALE is active only during a MOVX or MOVC instruction is used. Reset Value = 0X0X 1100b Not bit addressable 141 7683B–USB–03/07 27. Electrical Characteristics 27.1 Absolute Maximum Ratings Note: Ambient Temperature Under Bias: I = industrial ........................................................-40°C to 85°C Storage Temperature .................................... -65°C to + 150°C Voltage on VCC from VSS ......................................-0.5V to + 6V Voltage on Any Pin from VSS .....................-0.5V to VCC + 0.2V 27.2 Stresses at or above those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions may affect device reliability. DC Parameters TA = -40°C to +85°C; VSS = 0V; VCC = 2.7 - 3.6V; F = 0 to 40 MHz Symbol Parameter Min VIL Input Low Voltage VIH Input High Voltage except XTAL1, RST VIH1 Input High Voltage, XTAL1, RST VOL Output Low Voltage, ports 1, 2, 3 and 4(6) VOL1 VOH VOH1 RRST Output Low Voltage, port 0, ALE, PSEN Typ(5) Max Unit -0.5 0.2Vcc - 0.1 V 0.2 VCC + 0.9 VCC + 0.5 V 0.7 VCC VCC + 0.5 V (6) Output High Voltage, ports 1, 2, 3, 4 and 5 Output High Voltage, port 0, ALE, PSEN RST Pullup Resistor 0.3 V IOL = 100 µA(4) 0.45 V IOL = 0.8 mA(4) 1.0 V IOL = 1.6mA(4) 0.3 V IOL = 200 µA(4) 0.45 V IOL = 1.6 mA(4) 1.0 V IOL = 3.5 mA(4) VCC - 0.3 V VCC - 0.7 V VCC - 1.5 V VCC - 0.3 V VCC - 0.7 V VCC - 1.5 V 50 100 Test Conditions 200 kΩ IOH = -10 µA IOH = -30 µA IOH = -60 µA VCC = 2.7 - 3.6V IOH = -200 µA IOH = -1.6 mA IOH = -3.5 mA VCC = 2.7 - 3.6V IIL Logical 0 Input Current ports 1, 2, 3 and 4 -50 µA Vin = 0.45V ILI Input Leakage Current ±10 µA 0.45V < Vin < VCC ITL Logical 1 to 0 Transition Current, ports 1, 2, 3 and 4 -650 µA Vin = 2.0V CIO Capacitance of I/O Buffer 10 pF Fc = 1 MHz TA = 25°C IPD Power-down Current 100 µA 2.7V < VCC < 3.6V(3) ICC Power Supply Current ICCOP = 0.33xF(MHz)+1.46 VCC = 3.3V (1)(2) ICCIDLE = 0.3xF(MHz)+1.46 ICCwrite = 0.8xF(MHz)+15 VPFDP 142 Power Fail High Level Threshold 2.7 V AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 Symbol VPFDM Notes: Typ(5) Parameter Min Max Unit Power Fail Low Level Threshold 2.2 V Power fail hysteresis VPFDP - VPFDM 0.15 V Test Conditions 1. Operating ICC is measured with all output pins disconnected; XTAL1 driven with TCLCH, TCHCL = 5 ns (see Figure 27-4.), VIL = VSS + 0.5V, VIH = VCC - 0.5V; XTAL2 N.C.; EA = RST = Port 0 = VCC. ICC would be slightly higher if a crystal oscillator used (see Figure 27-1.). 2. Idle ICC is measured with all output pins disconnected; XTAL1 driven with TCLCH, TCHCL = 5 ns, VIL = VSS + 0.5V, VIH = VCC 0.5V; XTAL2 N.C; Port 0 = VCC; EA = RST = VSS (see Figure 27-2). 3. Power-down ICC is measured with all output pins disconnected; EA = VCC, PORT 0 = VCC; XTAL2 NC.; RST = VSS (see Figure 27-3.). In addition, the WDT must be inactive and the POF flag must be set. 4. Capacitance loading on Ports 0 and 2 may cause spurious noise pulses to be superimposed on the VOLS of ALE and Ports 1 and 3. The noise is due to external bus capacitance discharging into the Port 0 and Port 2 pins when these pins make 1 to 0 transitions during bus operation. In the worst cases (capacitive loading 100 pF), the noise pulse on the ALE line may exceed 0.45V with maxi VOL peak 0.6V. A Schmitt Trigger use is not necessary. 5. Typicals are based on a limited number of samples and are not guaranteed. The values listed are at room temperature. 6. Under steady state (non-transient) conditions, IOL must be externally limited as follows: Maximum IOL per port pin: 10 mA Maximum IOL per 8-bit port: Port 0: 26 mA Ports 1, 2 and 3: 15 mA Maximum total IOL for all output pins: 71 mA If IOL exceeds the test condition, VOL may exceed the related specification. Pins are not guaranteed to sink current greater than the listed test conditions. Figure 27-1. ICC Test Condition, Active Mode VCC ICC VCC VCC P0 RST (NC) CLOCK SIGNAL EA XTAL2 XTAL1 VSS All other pins are disconnected. 143 7683C–USB–11/07 Figure 27-2. ICC Test Condition, Idle Mode VCC ICC VCC P0 VCC RST (NC) CLOCK SIGNAL VCC EA XTAL2 XTAL1 VSS All other pins are disconnected. Figure 27-3. ICC Test Condition, Power-down Mode VCC ICC VCC VCC P0 VCC RST (NC) EA XTAL2 XTAL1 VSS All other pins are disconnected. Figure 27-4. Clock Signal Waveform for ICC Tests in Active and Idle Modes VCC-0.5V 0.45V TCLCH TCHCL TCLCH = TCHCL = 5ns. 27.2.1 LED’s Table 27-1. Symbol IOL Note: 144 0.7VCC 0.2VCC-0.1 LED Outputs DC Parameters Parameter Output Low Current, P3.6 and P3.7 LED modes Min Typ Max Unit Test Conditions 1 2 4 mA 2 mA configuration 2 4 8 mA 4 mA configuration 5 10 20 mA 10 mA configuration 1. (TA = -20°C to +50°C, VCC - VOL = 2 V ± 20%) AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 27.3 USB DC Parameters 1 - VBUS 2-D3-D+ 4 - GND R 3 2 USB “B” Receptacle VREF Rpad Rpad 4 D+ D- 1 R = 1.5 kΩ Rpad = 27Ω Symbol Parameter Min USB Reference Voltage 3.0 VIH Input High Voltage for D+ and D- (Driven) 2.0 VIHZ Input High Voltage for D+ and D- (Floating) 2.7 VIL Input Low Voltage for D+ and D- VOH Output High Voltage for D+ and D- VOL Output Low Voltage for D+ and D- VREF 27.4 27.4.1 Typ Max Unit 3.6 V V 3.6 V 0.8 V 2.8 3.6 V 0.0 0.3 V AC Parameters Explanation of the AC Symbols Each timing symbol has 5 characters. The first character is always a “T” (stands for time). The other characters, depending on their positions, stand for the name of a signal or the logical status of that signal. The following is a list of all the characters and what they stand for. Example:TAVLL = Time for Address Valid to ALE Low. TLLPL = Time for ALE Low to PSEN Low. TA = -40°C to +85°C; VSS = 0V; VCC = 2.7 - 3.6V; F = 0 to 40 MHz. TA = -40°C to +85°C; VSS = 0V; VCC = 2.7 - 3.6V. (Load Capacitance for port 0, ALE and PSEN = 60 pF; Load Capacitance for all other outputs = 60 pF.) Table 27-3, Table 27-6 and Table 27-9 give the description of each AC symbols. Table 27-4, Table 27-8 and Table 27-10 give for each range the AC parameter. Table 27-5, Table 27-8 and Table 27-11 give the frequency derating formula of the AC parameter for each speed range description. To calculate each AC symbols. take the x value and use this value in the formula. 145 7683C–USB–11/07 Example: TLLIV and 20 MHz, Standard clock. x = 30 ns T = 50 ns TCCIV = 4T - x = 170 ns 27.4.2 External Program Memory Characteristics Table 27-2. Symbol Description Symbol T Table 27-3. Parameter Oscillator Clock Period TLHLL ALE Pulse Width TAVLL Address Valid to ALE TLLAX Address Hold after ALE TLLIV ALE to Valid Instruction In TLLPL ALE to PSEN TPLPH PSEN Pulse Width TPLIV PSEN to Valid Instruction In TPXIX Input Instruction Hold after PSEN TPXIZ Input Instruction Float after PSEN TAVIV Address to Valid Instruction In TPLAZ PSEN Low to Address Float AC Parameters for a Fix Clock (F = 40 MHz) Symbol Min T 25 ns TLHLL 40 ns TAVLL 10 ns TLLAX 10 ns TLLIV 70 Units ns TLLPL 15 ns TPLPH 55 ns TPLIV TPXIX 146 Max 35 0 ns ns TPXIZ 18 ns TAVIV 85 ns TPLAZ 10 ns AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 Table 27-4. 27.4.3 AC Parameters for a Variable Clock Symbol Type Standard Clock X2 Clock X Parameter Units TLHLL Min 2T-x T-x 10 ns TAVLL Min T-x 0.5 T - x 15 ns TLLAX Min T-x 0.5 T - x 15 ns TLLIV Max 4T-x 2T-x 30 ns TLLPL Min T-x 0.5 T - x 10 ns TPLPH Min 3T-x 1.5 T - x 20 ns TPLIV Max 3T-x 1.5 T - x 40 ns TPXIX Min x x 0 ns TPXIZ Max T-x 0.5 T - x 7 ns TAVIV Max 5T-x 2.5 T - x 40 ns TPLAZ Max x x 10 ns External Program Memory Read Cycle 12 TCLCL TLHLL TLLIV ALE TLLPL TPLPH PSEN PORT 0 TLLAX TAVLL INSTR IN TPLIV TPLAZ A0-A7 TPXIX INSTR IN TPXAV TPXIZ A0-A7 INSTR IN TAVIV PORT 2 ADDRESS OR SFR-P2 ADDRESS A8-A15 ADDRESS A8-A15 147 7683C–USB–11/07 27.4.4 External Data Memory Characteristics Table 27-5. Symbol Description Symbol Table 27-6. Parameter TRLRH RD Pulse Width TWLWH WR Pulse Width TRLDV RD to Valid Data In TRHDX Data Hold After RD TRHDZ Data Float After RD TLLDV ALE to Valid Data In TAVDV Address to Valid Data In TLLWL ALE to WR or RD TAVWL Address to WR or RD TQVWX Data Valid to WR Transition TQVWH Data set-up to WR High TWHQX Data Hold After WR TRLAZ RD Low to Address Float TWHLH RD or WR High to ALE high AC Parameters for a Variable Clock (F = 40 MHz) Symbol Min TRLRH 130 ns TWLWH 130 ns TRLDV TRHDX 100 0 Units ns ns TRHDZ 30 ns TLLDV 160 ns TAVDV 165 ns 100 ns TLLWL 50 TAVWL 75 ns TQVWX 10 ns TQVWH 160 ns TWHQX 15 ns TRLAZ TWHLH 148 Max 10 0 ns 40 ns AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 Table 27-7. 27.4.5 AC Parameters for a Variable Clock Symbol Type Standard Clock X2 Clock X Parameter Units TRLRH Min 6T-x 3T-x 20 ns TWLWH Min 6T-x 3T-x 20 ns TRLDV Max 5T-x 2.5 T - x 25 ns TRHDX Min x x 0 ns TRHDZ Max 2T-x T-x 20 ns TLLDV Max 8T-x 4T -x 40 ns TAVDV Max 9T-x 4.5 T - x 60 ns TLLWL Min 3T-x 1.5 T - x 25 ns TLLWL Max 3T+x 1.5 T + x 25 ns TAVWL Min 4T-x 2T-x 25 ns TQVWX Min T-x 0.5 T - x 15 ns TQVWH Min 7T-x 3.5 T - x 25 ns TWHQX Min T-x 0.5 T - x 10 ns TRLAZ Max x x 0 ns TWHLH Min T-x 0.5 T - x 15 ns TWHLH Max T+x 0.5 T + x 15 ns External Data Memory Write Cycle TWHLH ALE PSEN TLLWL TWLWH WR TLLAX PORT 0 A0-A7 TQVWX TQVWH TWHQX DATA OUT TAVWL PORT 2 ADDRESS OR SFR-P2 ADDRESS A8-A15 OR SFR P2 149 7683C–USB–11/07 27.4.6 External Data Memory Read Cycle TWHLH TLLDV ALE PSEN TLLWL TRLRH RD TRHDZ TAVDV TLLAX PORT 0 TRHDX A0-A7 DATA IN TRLAZ TAVWL PORT 2 27.4.7 ADDRESS OR SFR-P2 ADDRESS A8-A15 OR SFR P2 Serial Port Timing - Shift Register Mode Table 27-8. Symbol Description (F = 40 MHz) Symbol Table 27-9. Parameter TXLXL Serial port clock cycle time TQVHX Output data set-up to clock rising edge TXHQX Output data hold after clock rising edge TXHDX Input data hold after clock rising edge TXHDV Clock rising edge to input data valid AC Parameters for a Fix Clock (F = 40 MHz) Symbol Min Max Units TXLXL 300 ns TQVHX 200 ns TXHQX 30 ns TXHDX 0 ns 117 TXHDV ns Table 27-10. AC Parameters for a Variable Clock 150 Symbol Type Standard Clock X2 Clock X Parameter for -M Range TXLXL Min 12 T 6T TQVHX Min 10 T - x 5T-x 50 ns TXHQX Min 2T-x T-x 20 ns TXHDX Min x x 0 ns TXHDV Max 10 T - x 5 T- x 133 ns Units ns AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 27.4.8 Shift Register Timing Waveform INSTRUCTION 0 1 2 3 4 5 6 7 8 ALE TXLXL CLOCK TXHQX TQVXH OUTPUT DATA WRITE to SBUF INPUT DATA 0 1 2 3 4 5 6 TXHDX TXHDV VALID VALID SET TI VALID VALID VALID VALID VALID External Clock Drive Characteristics (XTAL1) Table 27-11. AC Parameters Symbol Parameter Min Max Units TCLCL Oscillator Period 21 ns TCHCX High Time 5 ns TCLCX Low Time 5 ns TCLCH Rise Time 5 ns TCHCL Fall Time 5 ns 60 % TCHCX/TCLCX 27.4.10 VALID SET RI CLEAR RI 27.4.9 7 Cyclic ratio in X2 mode 40 External Clock Drive Waveforms VCC-0.5V 0.45V 0.7VCC 0.2VCC-0.1 TCHCX TCLCX TCHCL TCLCH TCLCL 27.4.11 AC Testing Input/Output Waveforms VCC -0.5V 0.2 VCC + 0.9 INPUT/OUTPUT 0.2 VCC - 0.1 0.45V AC inputs during testing are driven at VCC - 0.5 for a logic “1” and 0.45V for a logic “0”. Timing measurement are made at VIH min for a logic “1” and VIL max for a logic “0”. 27.4.12 Float Waveforms FLOAT VOH - 0.1 V VOL + 0.1 V VLOAD VLOAD + 0.1 V VLOAD - 0.1 V For timing purposes as 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 loaded VOH/VOL level occurs. IOL/IOH ≥ ±20 mA. 151 7683C–USB–11/07 27.4.13 Clock Waveforms Valid in normal clock mode. In X2 mode XTAL2 must be changed to XTAL2/2. INTERNAL CLOCK STATE4 STATE5 STATE6 STATE1 STATE2 STATE3 STATE4 STATE5 P1 P1 P1 P1 P1 P1 P1 P1 P2 P2 P2 P2 P2 P2 P2 P2 XTAL2 ALE THESE SIGNALS ARE NOT ACTIVATED DURING THE EXECUTION OF A MOVX INSTRUCTION EXTERNAL PROGRAM MEMORY FETCH PSEN P0 DATA SAMPLED FLOAT P2 (EXT) PCL OUT DATA SAMPLED FLOAT PCL OUT DATA SAMPLED FLOAT PCL OUT INDICATES ADDRESS TRANSITIONS READ CYCLE RD PCL OUT (IF PROGRAM MEMORY IS EXTERNAL) P0 DPL OR Rt OUT P2 DATA SAMPLED FLOAT INDICATES DPH OR P2 SFR TO PCH TRANSITION WRITE CYCLE WR P0 PCL OUT (EVEN IF PROGRAM MEMORY IS INTERNAL) DPL OR Rt OUT PCL OUT (IF PROGRAM MEMORY IS EXTERNAL) DATA OUT P2 INDICATES DPH OR P2 SFR TO PCH TRANSITION PORT OPERATION MOV PORT SRC OLD DATA NEW DATA P0 PINS SAMPLED P0 PINS SAMPLED MOV DEST P0 MOV DEST PORT (P1. P2. P3) (INCLUDES INTO. INT1. TO T1) SERIAL PORT SHIFT CLOCK P1, P2, P3 PINS SAMPLED RXD SAMPLED P1, P2, P3 PINS SAMPLED RXD SAMPLED TXD (MODE 0) This diagram indicates when signals are clocked internally. The time it takes the signals to propagate to the pins, however, ranges from 25 to 125 ns. This propagation delay is dependent on variables such as temperature and pin loading. Propagation also varies from output to output and component. Typically though (TA = 25°C fully loaded) RD and WR propagation delays are approximately 50 ns. The other signals are typically 85 ns. Propagation delays are incorporated in the AC specifications. 152 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 Table 27-12. Memory AC Timing VDD = 3.3V ± 10%, TA = -40 to +85°C Symbol 27.5 Parameter Min Typ Max Unit TSVRL Input PSEN Valid to RST Edge 50 ns TRLSX Input PSEN Hold after RST Edge 50 ns USB AC Parameters Rise Time Fall Time 90% VHmin 90% VCRS 10% 10% Differential Data Lines VLmax tF tR Table 27-13. USB AC Parameters Symbol Parameter Min tR Rise Time tF Fall Time Max Unit 4 20 ns 4 20 ns 11.9700 12.0300 Mb/s Crossover Voltage 1.3 2.0 V tDJ1 Source Jitter Total to Next Transaction -3.5 3.5 ns tDJ2 Source Jitter Total for Paired Transactions -4 4 ns tJR1 Receiver Jitter to Next Transaction -18.5 18.5 ns tJR2 Receiver Jitter for Paired Transactions -9 9 ns tFDRATE VCRS 27.6 Full-speed Data Rate Typ Test Conditions SPI Interface AC Parameters 27.6.0.1 Definition of Symbols Table 27-14. SPI Interface Timing Symbol Definitions Signals Conditions C Clock H High I Data In L Low O Data Out V Valid X No Longer Valid Z Floating 153 7683C–USB–11/07 27.6.0.2 Timings Test conditions: capacitive load on all pins= 50 pF. Table 27-15. SPI Interface Master AC Timing VDD = 2.7 to 5.5 V, TA = -40 to +85°C Symbol Parameter Min Max Unit Slave Mode TCHCH Clock Period 2 TPER TCHCX Clock High Time 0.8 TPER TCLCX Clock Low Time 0.8 TPER TSLCH, TSLCL SS Low to Clock edge 100 ns TIVCL, TIVCH Input Data Valid to Clock Edge 50 ns TCLIX, TCHIX Input Data Hold after Clock Edge 50 ns TCLOV, TCHOV Output Data Valid after Clock Edge TCLOX, TCHOX Output Data Hold Time after Clock Edge 0 ns TCLSH, TCHSH SS High after Clock Edge 0 ns TSLOV SS Low to Output Data Valid 4TPER+20 ns TSHOX Output Data Hold after SS High 2TPER+100 ns TSHSL SS High to SS Low TILIH Input Rise Time 2 µs TIHIL Input Fall Time 2 µs TOLOH Output Rise time 100 ns TOHOL Output Fall Time 100 ns 50 ns 2TPER+120 Master Mode Note: 154 TCHCH Clock Period 4 TPER TCHCX Clock High Time 2TPER-20 ns TCLCX Clock Low Time 2TPER-20 ns TIVCL, TIVCH Input Data Valid to Clock Edge 50 ns TCLIX, TCHIX Input Data Hold after Clock Edge 50 ns TCLOV, TCHOV Output Data Valid after Clock Edge TCLOX, TCHOX Output Data Hold Time after Clock Edge 20 0 ns ns TPER is XTAL period when SPI interface operates in X2 mode or twice XTAL period when SPI interface operates in X1 mode. AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 27.6.0.3 Waveforms Figure 27-5. SPI Slave Waveforms (CPHA= 0) SS (input) TSLCH TSLCL TCHCH SCK (CPOL= 0) (input) TCHCX TSHSL TCLCX TCHCL SCK (CPOL= 1) (input) TCLOX TCHOX TCLOV TCHOV TSLOV MISO (output) TCLCH TCLSH TCHSH SLAVE MSB OUT BIT 6 TSHOX SLAVE LSB OUT (1) TIVCH TCHIX TIVCL TCLIX MOSI (input) Note: MSB IN BIT 6 LSB IN 1. Not Defined but generally the MSB of the character which has just been received. Figure 27-6. SPI Slave Waveforms (CPHA= 1) SS (input) TSLCH TSLCL SCK (CPOL= 0) (input) TCHCH TCHCX TSHSL TCLCX TCHCL SCK (CPOL= 1) (input) TCHOV TCLOV TSLOV MISO (output) TCLCH TCLSH TCHSH (1) SLAVE MSB OUT BIT 6 TCHOX TCLOX TSHOX SLAVE LSB OUT TIVCH TCHIX TIVCL TCLIX MOSI (input) Note: MSB IN BIT 6 LSB IN 1. Not Defined but generally the LSB of the character which has just been received. 155 7683C–USB–11/07 Figure 27-7. SPI Master Waveforms (SSCPHA= 0) SS (output) TCHCH SCK (CPOL= 0) (output) TCHCX TCLCH TCLCX TCHCL SCK (CPOL= 1) (output) TIVCH TCHIX TIVCL TCLIX MOSI (input) MSB IN BIT 6 LSB IN TCLOX TCLOV TCHOV MISO (output) Note: Port Data MSB OUT TCHOX BIT 6 LSB OUT Port Data 1. SS handled by software using general purpose port pin. Figure 27-8. SPI Master Waveforms (SSCPHA= 1) SS(1) (output) TCHCH SCK (CPOL= 0) (output) TCHCX TCLCH TCLCX TCHCL SCK (CPOL= 1) (output) TIVCH TCHIX TIVCL TCLIX MOSI (input) MISO (output) MSB IN BIT 6 TCLOV TCLOX TCHOX TCHOV Port Data MSB OUT BIT 6 LSB IN LSB OUT Port Data SS handled by software using general purpose port pin. 156 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 28. Ordering Information Table Possible Order Entries Part Number Memory Size Supply Voltage Temperature Range Package Packing AT83C5134xxx-PNTUL 8KB 2.7 to 3.6V Industrial & Green QFN32 Tray AT83C5135xxx-PNTUL 16KB 2.7 to 3.6V Industrial & Green QFN32 Tray AT83C5136xxx-PNTUL 32KB 2.7 to 3.6V Industrial & Green QFN32 Tray AT83C5136xxx-PLTUL 32KB 2.7 to 3.6V Industrial & Green QFN/MLF48 Tray AT83C5136xxx-TISUL 32KB 2.7 to 3.6V Industrial & Green SO28 Stick AT83C5136-RDTUL 32 2.7 to 3.6V Industrial & Green VQFP64 Tray AT83C5136xxx-DDW 32KB 2.7 to 3.6V Industrial & Green Die Inked Wafer AT83EC5136xxx-PNTUL 32KB with 512-byte of EEPROM 2.7 to 3.6V Industrial & Green QFN/MLF48 Tray AT83EI5136xxx-PNTUL 32KB with 32-kbyte of EEPROM 2.7 to 3.6V Industrial & Green QFN/MLF48 Tray 157 7683C–USB–11/07 29. Packaging Information 29.1 158 64-lead VQFP AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 29.2 48-lead MLF 159 7683C–USB–11/07 160 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 29.3 28-lead SO 161 7683C–USB–11/07 29.4 162 QFN32 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 30. Document Revision History 30.1 Changes from Rev A. to Rev. B 1. Added QFN32 package. 30.2 Changes from Rev B. to Rev. C 1. Updated package drawings. 163 7683C–USB–11/07 1 Features .................................................................................................... 1 2 Description ............................................................................................... 1 3 Block Diagram .......................................................................................... 3 4 Pinout Description ................................................................................... 4 5 6 4.1 Pinout ................................................................................................................ 4 4.2 Signals............................................................................................................... 6 Typical Application ................................................................................ 11 5.1 Recommended External components ............................................................. 11 5.2 PCB Recommandations .................................................................................. 12 Clock Controller ..................................................................................... 13 6.1 Introduction...................................................................................................... 13 6.2 Oscillator.......................................................................................................... 13 6.3 PLL .................................................................................................................. 14 6.4 Registers ......................................................................................................... 16 7 SFR Mapping .......................................................................................... 18 8 Program/Code Memory ......................................................................... 25 8.1 9 External Code Memory Access ....................................................................... 25 AT89C5131 ROM .................................................................................... 27 9.1 ROM Structure................................................................................................. 27 9.2 ROM Lock System........................................................................................... 27 10 Stacked EEPROM................................................................................... 29 10.1 Overview.......................................................................................................... 29 10.2 Protocol ........................................................................................................... 29 11 On-chip Expanded RAM (ERAM) .......................................................... 30 12 Timer 2 .................................................................................................... 33 12.1 Auto-reload Mode ............................................................................................ 33 12.2 Programmable Clock Output ........................................................................... 34 13 Programmable Counter Array (PCA).................................................... 38 164 13.1 PCA Capture Mode ......................................................................................... 45 13.2 16-bit Software Timer/Compare Mode ............................................................ 45 13.3 High Speed Output Mode ................................................................................ 46 13.4 Pulse Width Modulator Mode .......................................................................... 47 AT83C5134/35/36 7683C–USB–11/07 AT83C5134/35/36 13.5 PCA Watchdog Timer...................................................................................... 48 14 Serial I/O Port ......................................................................................... 49 14.1 Framing Error Detection .................................................................................. 49 14.2 Automatic Address Recognition ...................................................................... 50 14.3 Baud Rate Selection for UART for Mode 1 and 3............................................ 52 14.4 UART Registers............................................................................................... 55 15 Dual Data Pointer Register.................................................................... 59 16 Interrupt System .................................................................................... 61 16.1 Overview.......................................................................................................... 61 16.2 Registers ......................................................................................................... 62 16.3 Interrupt Sources and Vector Addresses......................................................... 69 17 Keyboard Interface ................................................................................ 70 17.1 Introduction...................................................................................................... 70 17.2 Description....................................................................................................... 70 17.3 Registers ......................................................................................................... 71 18 Programmable LED................................................................................ 74 19 Serial Peripheral Interface (SPI) ........................................................... 75 19.1 Features .......................................................................................................... 75 19.2 Signal Description............................................................................................ 75 19.3 Functional Description ..................................................................................... 77 20 Two Wire Interface (TWI) ....................................................................... 84 20.1 Description....................................................................................................... 86 20.2 Notes ............................................................................................................... 89 20.3 Registers ......................................................................................................... 99 21 USB Controller ..................................................................................... 101 21.1 Description..................................................................................................... 101 21.2 Configuration ................................................................................................. 103 21.3 Read/Write Data FIFO................................................................................... 105 21.4 Bulk/Interrupt Transactions............................................................................ 106 21.5 Control Transactions ..................................................................................... 111 21.6 Isochronous Transactions ............................................................................. 112 21.7 Miscellaneous................................................................................................ 113 21.8 Suspend/Resume Management .................................................................... 114 165 7683C–USB–11/07 21.9 Detach Simulation ......................................................................................... 117 21.10 USB Interrupt System.................................................................................... 117 21.11 USB Registers ............................................................................................... 120 22 Reset ..................................................................................................... 131 22.1 Introduction.................................................................................................... 131 22.2 Reset Input .................................................................................................... 131 22.3 Reset Output ................................................................................................. 131 23 Power Monitor ...................................................................................... 133 23.1 Description..................................................................................................... 133 24 Power Management ............................................................................. 135 24.1 Idle Mode....................................................................................................... 135 24.2 Power-down Mode......................................................................................... 135 24.3 Registers ....................................................................................................... 137 25 Hardware Watchdog Timer ................................................................. 138 25.1 Using the WDT .............................................................................................. 138 25.2 WDT During Power-down and Idle ................................................................ 139 26 Reduced EMI Mode .............................................................................. 141 27 Electrical Characteristics .................................................................... 142 27.1 Absolute Maximum Ratings .......................................................................... 142 27.2 DC Parameters.............................................................................................. 142 27.3 USB DC Parameters ..................................................................................... 145 27.4 AC Parameters .............................................................................................. 145 27.5 USB AC Parameters...................................................................................... 153 27.6 SPI Interface AC Parameters ........................................................................ 153 28 Ordering Information ........................................................................... 157 29 Packaging Information ........................................................................ 158 29.1 64-lead VQFP................................................................................................ 158 29.2 48-lead MLF .................................................................................................. 159 29.3 28-lead SO .................................................................................................... 161 29.4 QFN32 ........................................................................................................... 162 30 Document Revision History ................................................................ 163 166 30.1 Changes from Rev A. to Rev. B .................................................................... 163 30.2 Changes from Rev B. to Rev. C .................................................................... 163 AT83C5134/35/36 7683C–USB–11/07 Headquarters International Atmel Corporation 2325 Orchard Parkway San Jose, CA 95131 USA Tel: 1(408) 441-0311 Fax: 1(408) 487-2600 Atmel Asia Room 1219 Chinachem Golden Plaza 77 Mody Road Tsimshatsui East Kowloon Hong Kong Tel: (852) 2721-9778 Fax: (852) 2722-1369 Atmel Europe Le Krebs 8, Rue Jean-Pierre Timbaud BP 309 78054 Saint-Quentin-enYvelines Cedex France Tel: (33) 1-30-60-70-00 Fax: (33) 1-30-60-71-11 Atmel Japan 9F, Tonetsu Shinkawa Bldg. 1-24-8 Shinkawa Chuo-ku, Tokyo 104-0033 Japan Tel: (81) 3-3523-3551 Fax: (81) 3-3523-7581 Technical Support Enter Product Line E-mail Sales Contact www.atmel.com/contacts Product Contact Web Site www.atmel.com Literature Requests www.atmel.com/literature Disclaimer: The information in this document is provided in connection with Atmel products. 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