*/
#define SERIAL_BAUD 19200
#define SERIAL_PARITY_ODD
-#define SERIAL_BIT_ORDER_MSB
+#define SERIAL_BIT_ORDER_LSB
#define SERIAL_RXD_DDR DDRD
#define SERIAL_RXD_PORT PORTD
SERIAL_RXD_DDR &= ~(1<<SERIAL_RXD_BIT); \
SERIAL_RXD_PORT |= (1<<SERIAL_RXD_BIT); \
/* enable interrupt: INT2(rising edge) */ \
- EICRA |= ((1<<ISC21)|(1<<ISC20)); \
+ /*EICRA |= ((1<<ISC21)|(1<<ISC20));*/ \
+ /* enable interrupt: INT2(falling edge) */ \
+ EICRA |= ((1<<ISC21)|(0<<ISC20)); \
EIMSK |= (1<<INT2); \
} while (0)
#define SERIAL_RXD_INT_ENTER()
/* clear interrupt flag */ \
EIFR = (1<<INTF2); \
} while (0)
-#define SERIAL_RXD_READ() (~SERIAL_RXD_PIN&(1<<SERIAL_RXD_BIT))
+//#define SERIAL_RXD_READ() (~SERIAL_RXD_PIN&(1<<SERIAL_RXD_BIT))
+#define SERIAL_RXD_READ() ((SERIAL_RXD_PIN&(1<<SERIAL_RXD_BIT)))
#define SERIAL_TXD_DDR DDRD
#define SERIAL_TXD_PORT PORTD
PC98_RDY_PORT |= (1<<PC98_RDY_BIT);
PC98_RTY_PORT |= (1<<PC98_RTY_BIT);
+ DDRD |= 1<<7;
+
serial_init();
_delay_us(13);
PC98_RDY_PORT |= (1<<PC98_RDY_BIT);
+ // PC98 ready
+ PC98_RDY_PORT &= ~(1<<PC98_RDY_BIT);
+
// initialize matrix state: all keys off
for (uint8_t i=0; i < MATRIX_ROWS; i++) matrix[i] = 0x00;
uint8_t code;
PC98_RDY_PORT |= (1<<PC98_RDY_BIT);
+ _delay_us(30);
code = serial_recv();
PC98_RDY_PORT &= ~(1<<PC98_RDY_BIT);
if (!code) return 0;
#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)
{
SERIAL_RXD_INIT();
static uint8_t rbuf_head = 0;
static uint8_t rbuf_tail = 0;
+
uint8_t serial_recv(void)
{
uint8_t data = 0;
/* detect edge of start bit */
ISR(SERIAL_RXD_VECT)
{
+PORTD ^= 1<<7;
SERIAL_RXD_INT_ENTER()
uint8_t data = 0;
#endif
/* to center of start bit */
- _delay_us(WAIT_US/2);
+ //_delay_us(WAIT_US/2);
+ WAIT4(WAIT_TICK/2);
+PORTD ^= 1<<7;
do {
/* to center of next bit */
- _delay_us(WAIT_US);
+ //_delay_us(WAIT_US);
+ WAIT4(WAIT_TICK);
+PORTD ^= 1<<7;
if (SERIAL_RXD_READ()) {
data |= mask;
parity ^= 1;
} while (mask);
/* 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 */
- _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;
- if (parity && next != rbuf_tail) {
+ //if (parity && next != rbuf_tail) {
+ if (next != rbuf_tail) {
rbuf[rbuf_head] = data;
rbuf_head = next;
}
SERIAL_RXD_INT_EXIT();
+PORTD ^= 1<<7;
}