tmk
11 years ago
1 changed files with 34 additions and 8 deletions
+ 34
- 8
protocol/serial_soft.c
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| #define WAIT_US (1000000/SERIAL_BAUD) | #define WAIT_US (1000000/SERIAL_BAUD) | ||||
| #if 1 | |||||
| #define WAIT_TICK (1000000/SERIAL_BAUD) | |||||
| #define WAIT4(tick) _delay_us(tick) | |||||
| #else | |||||
| #define WAIT_TICK ((16000000/SERIAL_BAUD)/4 - 5) | |||||
| static inline void WAIT4(uint8_t tick) | |||||
| { | |||||
| __asm__ __volatile__ ( | |||||
| "1: dec %0" "\n\t" | |||||
| "nop" "\n\t" | |||||
| "brne 1b" | |||||
| : | |||||
| : "r" (tick) | |||||
| ); | |||||
| } | |||||
| #endif | |||||
| void serial_init(void) | void serial_init(void) | ||||
| { | { | ||||
| SERIAL_RXD_INIT(); | SERIAL_RXD_INIT(); | ||||
| static uint8_t rbuf_head = 0; | static uint8_t rbuf_head = 0; | ||||
| static uint8_t rbuf_tail = 0; | static uint8_t rbuf_tail = 0; | ||||
| uint8_t serial_recv(void) | uint8_t serial_recv(void) | ||||
| { | { | ||||
| uint8_t data = 0; | uint8_t data = 0; | ||||
| /* detect edge of start bit */ | /* detect edge of start bit */ | ||||
| ISR(SERIAL_RXD_VECT) | ISR(SERIAL_RXD_VECT) | ||||
| { | { | ||||
| PORTD ^= 1<<7; | |||||
| SERIAL_RXD_INT_ENTER() | SERIAL_RXD_INT_ENTER() | ||||
| uint8_t data = 0; | uint8_t data = 0; | ||||
| #endif | #endif | ||||
| /* to center of start bit */ | /* to center of start bit */ | ||||
| _delay_us(WAIT_US/2); | |||||
| //_delay_us(WAIT_US/2); | |||||
| WAIT4(WAIT_TICK/2); | |||||
| PORTD ^= 1<<7; | |||||
| do { | do { | ||||
| /* to center of next bit */ | /* to center of next bit */ | ||||
| _delay_us(WAIT_US); | |||||
| //_delay_us(WAIT_US); | |||||
| WAIT4(WAIT_TICK); | |||||
| PORTD ^= 1<<7; | |||||
| if (SERIAL_RXD_READ()) { | if (SERIAL_RXD_READ()) { | ||||
| data |= mask; | data |= mask; | ||||
| parity ^= 1; | parity ^= 1; | ||||
| } while (mask); | } while (mask); | ||||
| /* to center of parity bit */ | /* to center of parity bit */ | ||||
| _delay_us(WAIT_US); | |||||
| parity ^= SERIAL_RXD_READ(); | |||||
| //_delay_us(WAIT_US); | |||||
| WAIT4(WAIT_TICK); | |||||
| if (SERIAL_RXD_READ()) { parity ^= 1; } | |||||
| PORTD ^= 1<<7; | |||||
| /* to center of stop bit */ | /* to center of stop bit */ | ||||
| _delay_us(WAIT_US); | |||||
| _delay_us(WAIT_US/2); | |||||
| //_delay_us(WAIT_US); | |||||
| WAIT4(WAIT_TICK); | |||||
| parity = 1; | |||||
| uint8_t next = (rbuf_head + 1) % RBUF_SIZE; | uint8_t next = (rbuf_head + 1) % RBUF_SIZE; | ||||
| if (parity && next != rbuf_tail) { | |||||
| //if (parity && next != rbuf_tail) { | |||||
| if (next != rbuf_tail) { | |||||
| rbuf[rbuf_head] = data; | rbuf[rbuf_head] = data; | ||||
| rbuf_head = next; | rbuf_head = next; | ||||
| } | } | ||||
| SERIAL_RXD_INT_EXIT(); | SERIAL_RXD_INT_EXIT(); | ||||
| PORTD ^= 1<<7; | |||||
| } | } |