mirror of
https://github.com/halleysfifthinc/Toyota-AVC-LAN
synced 2025-06-06 15:36:47 +00:00
Implement bit-read timing with TCB0 pulse-width measurement
This commit is contained in:
Allen Hill
parent
d6d1995ae4
commit
09bcd75811
150
src/avclandrv.c
150
src/avclandrv.c
@ -85,6 +85,7 @@
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--------------------------------------------------------------------------------------
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*/
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#include <avr/interrupt.h>
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#include <avr/io.h>
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#include <avr/sfr_defs.h>
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#include <stdint.h>
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@ -256,6 +257,16 @@ void AVCLAN_init() {
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PORTB.DIRSET = PIN2_bm; // Enable AC2 OUT for LED
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PORTB.PIN2CTRL = PORT_ISC_INPUT_DISABLE_gc; // Output only
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// Set AC2 to generate events on async channel 0
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EVSYS.ASYNCCH0 = EVSYS_ASYNCCH0_AC2_OUT_gc;
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EVSYS.ASYNCUSER0 = EVSYS_ASYNCUSER0_ASYNCCH0_gc; // USER0 is TCB0
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// TCB0 for read bit timing
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TCB0.CTRLB = TCB_CNTMODE_PW_gc;
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TCB0.INTCTRL = TCB_CAPT_bm;
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TCB0.EVCTRL = TCB_CAPTEI_bm;
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TCB0.CTRLA = TCB_CLKSEL_CLKDIV2_gc | TCB_ENABLE_bm;
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// TCB1 for send bit timing
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TCB1.CTRLB = TCB_CNTMODE_INT_gc;
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TCB1.CCMP = 0xFFFF;
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@ -330,8 +341,8 @@ void AVCLAN_sendbit_parity(uint8_t parity) {
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uint8_t *: AVCLAN_sendbitsi)(bits, len)
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// Send `len` bits on the AVCLAN bus; returns the even parity
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uint8_t AVCLAN_sendbitsi(const uint8_t *byte, int8_t len) {
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uint8_t b = *byte;
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uint8_t AVCLAN_sendbitsi(const uint8_t *bits, int8_t len) {
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uint8_t b = *bits;
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uint8_t parity = 0;
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int8_t len_mod8 = 8;
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@ -352,14 +363,14 @@ uint8_t AVCLAN_sendbitsi(const uint8_t *byte, int8_t len) {
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b <<= 1;
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}
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len_mod8 = 8;
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b = *--byte;
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b = *--bits;
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}
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return (parity & 1);
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}
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// Send `len` bits on the AVCLAN bus; returns the even parity
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uint8_t AVCLAN_sendbitsl(const uint16_t *word, int8_t len) {
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return AVCLAN_sendbitsi((const uint8_t *)word + 1, len);
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uint8_t AVCLAN_sendbitsl(const uint16_t *bits, int8_t len) {
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return AVCLAN_sendbitsi((const uint8_t *)bits + 1, len);
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}
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uint8_t AVCLAN_sendbyte(const uint8_t *byte) {
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@ -378,22 +389,73 @@ uint8_t AVCLAN_sendbyte(const uint8_t *byte) {
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return (parity & 1);
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}
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uint8_t AVCLAN_readbyte(uint8_t length, uint8_t *parity) {
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uint8_t byte = 0;
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#define READING_BYTE GPIOR1
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#define READING_NBITS GPIOR2
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#define READING_PARITY GPIOR3
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while (1) {
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while (INPUT_IS_CLEAR) {};
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TCB1.CNT = 0;
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while (INPUT_IS_SET) {}; // If input was set for less than 26 us
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if (TCB1.CNT < 208) { // (a generous half period), bit was a 1
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byte++;
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(*parity)++;
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}
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length--;
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if (!length)
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return byte;
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byte = byte << 1;
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ISR(TCB0_INT_vect) {
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// If input was set for less than 26 us (a generous half period), bit was a 1
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if (TCB0.CCMP < 208) {
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READING_BYTE++;
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READING_PARITY++;
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}
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READING_BYTE <<= 1;
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READING_NBITS--;
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}
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#define AVCLAN_readbits(bits, len) \
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_Generic((bits), \
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const uint16_t *: AVCLAN_readbitsl, \
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uint16_t *: AVCLAN_readbitsl, \
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const uint8_t *: AVCLAN_readbitsi, \
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uint8_t *: AVCLAN_readbitsi)(bits, len)
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// Send `len` bits on the AVCLAN bus; returns the even parity
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uint8_t AVCLAN_readbitsi(uint8_t *bits, uint8_t len) {
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cli();
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READING_BYTE = 0;
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READING_PARITY = 0;
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READING_NBITS = len;
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sei();
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while (READING_NBITS != 0) {};
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cli();
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*bits = READING_BYTE;
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uint8_t parity = READING_PARITY;
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sei();
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return (parity & 1);
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}
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// Send `len` bits on the AVCLAN bus; returns the even parity
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uint8_t AVCLAN_readbitsl(uint16_t *bits, int8_t len) {
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uint8_t parity = 0;
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if (len > 8) {
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uint8_t over = len - 8;
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parity = AVCLAN_readbitsi((uint8_t *)bits + 0, over);
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len -= over;
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}
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parity += AVCLAN_readbitsi((uint8_t *)bits + 1, len);
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return (parity & 1);
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}
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// Read a byte on the AVCLAN bus
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uint8_t AVCLAN_readbyte(uint8_t *byte) {
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cli();
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READING_BYTE = 0;
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READING_NBITS = 8;
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sei();
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while (READING_NBITS != 0) {};
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cli();
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*byte = READING_BYTE;
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uint8_t parity = READING_PARITY;
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sei();
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return (parity & 1);
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}
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uint8_t AVCLAN_readbit_ACK() {
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@ -455,27 +517,21 @@ uint8_t AVCLAN_readframe() {
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// return 0;
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// }
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uint8_t parity = 0;
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uint8_t parity_check = 0;
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AVCLAN_readbyte(1, &parity); // Start bit
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uint8_t tmp = 0;
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AVCLAN_readbits(&tmp, 1); // Start bit
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frame.broadcast = AVCLAN_readbyte(1, &parity);
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AVCLAN_readbits((uint8_t *)&frame.broadcast, 1);
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parity = 0;
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uint8_t *controller_hi = ((uint8_t *)&frame.controller_addr) + 1;
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uint8_t *controller_lo = ((uint8_t *)&frame.controller_addr) + 0;
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*controller_hi = AVCLAN_readbyte(4, &parity);
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*controller_lo = AVCLAN_readbyte(8, &parity);
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if ((parity & 1) != AVCLAN_readbyte(1, &parity_check)) {
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parity = AVCLAN_readbits(&frame.controller_addr, 12);
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AVCLAN_readbits(&tmp, 1);
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if (parity != tmp) {
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STARTEvent;
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return 0;
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}
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parity = 0;
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uint8_t *peripheral_hi = ((uint8_t *)&frame.peripheral_addr) + 1;
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uint8_t *peripheral_lo = ((uint8_t *)&frame.peripheral_addr) + 0;
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*peripheral_hi = AVCLAN_readbyte(4, &parity);
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*peripheral_lo = AVCLAN_readbyte(8, &parity);
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if ((parity & 1) != AVCLAN_readbyte(1, &parity_check)) {
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parity = AVCLAN_readbits(&frame.peripheral_addr, 12);
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AVCLAN_readbits(&tmp, 1);
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if (parity != tmp) {
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STARTEvent;
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return 0;
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}
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@ -486,28 +542,28 @@ uint8_t AVCLAN_readframe() {
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if (for_me)
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AVCLAN_sendbit_ACK();
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else
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AVCLAN_readbyte(1, &parity);
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AVCLAN_readbits(&tmp, 1);
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parity = 0;
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frame.control = AVCLAN_readbyte(4, &parity);
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if ((parity & 1) != AVCLAN_readbyte(1, &parity_check)) {
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parity = AVCLAN_readbits(&frame.control, 4);
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AVCLAN_readbits(&tmp, 1);
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if (parity != tmp) {
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STARTEvent;
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return 0;
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} else if (for_me) {
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AVCLAN_sendbit_ACK();
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} else {
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AVCLAN_readbyte(1, &parity);
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AVCLAN_readbits(&tmp, 1);
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}
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parity = 0;
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frame.length = AVCLAN_readbyte(8, &parity);
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if ((parity & 1) != AVCLAN_readbyte(1, &parity_check)) {
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parity = AVCLAN_readbyte(&frame.length);
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AVCLAN_readbits(&tmp, 1);
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if (parity != tmp) {
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STARTEvent;
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return 0;
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} else if (for_me) {
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AVCLAN_sendbit_ACK();
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} else {
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AVCLAN_readbyte(1, &parity);
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AVCLAN_readbits(&tmp, 1);
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}
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if (frame.length > MAXMSGLEN) {
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@ -517,15 +573,15 @@ uint8_t AVCLAN_readframe() {
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}
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for (i = 0; i < frame.length; i++) {
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parity = 0;
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frame.data[i] = AVCLAN_readbyte(8, &parity);
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if ((parity & 1) != AVCLAN_readbyte(1, &parity_check)) {
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parity = AVCLAN_readbyte(&frame.data[i]);
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AVCLAN_readbits(&tmp, 1);
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if (parity != tmp) {
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STARTEvent;
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return 0;
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} else if (for_me) {
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AVCLAN_sendbit_ACK();
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} else {
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AVCLAN_readbyte(1, &parity);
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AVCLAN_readbits(&tmp, 1);
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}
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}
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