#define RTSEN 0
#define CTSEN 1
- #define SERIAL_UART_BAUD 115200
- #define SERIAL_UART_DATA UDR1
- #define SERIAL_UART_UBRR ((F_CPU/(16.0*SERIAL_UART_BAUD)-1+0.5))
- #define SERIAL_UART_RXD_VECT USART1_RX_vect
- #define SERIAL_UART_TXD_READY (UCSR1A&(1<<UDRE1))
- #define SERIAL_UART_INIT() do { \
+ #define SERIAL_UART_BAUD 115200
+ #define SERIAL_UART_DATA UDR1
+ #define SERIAL_UART_UBRR ((F_CPU/(16.0*SERIAL_UART_BAUD)-1+0.5))
+ #define SERIAL_UART_RXD_VECT USART1_RX_vect
+ #define SERIAL_UART_TXD_READY (UCSR1A&(1<<UDRE1))
+ #define SERIAL_UART_INIT() do { \
UBRR1L = (uint8_t) SERIAL_UART_UBRR; /* baud rate */ \
UBRR1H = ((uint16_t)SERIAL_UART_UBRR>>8); /* baud rate */ \
UCSR1B |= (1<<RXCIE1) | (1<<RXEN1); /* RX interrupt, RX: enable */ \
UCSR1B |= (0<<TXCIE1) | (1<<TXEN1); /* TX interrupt, TX: enable */ \
UCSR1C |= (0<<UPM11) | (0<<UPM10); /* parity: none(00), even(01), odd(11) */ \
- UCSR1D |= (0<<RTSEN) | (0<<CTSEN); /* RTS, CTS */ \
+ UCSR1D |= (0<<RTSEN) | (0<<CTSEN); /* RTS, CTS(no flow control by hardware) */ \
+ DDRD |= (1<<5); PORTD &= ~(1<<5); /* RTS for flow control by firmware */ \
sei(); \
} while(0)
+ #define SERIAL_UART_RTS_LO() do { PORTD &= ~(1<<5); } while (0)
+ #define SERIAL_UART_RTS_HI() do { PORTD |= (1<<5); } while (0)
#else
#error "USART configuration is needed."
#endif
#include "serial.h"
+#if defined(SERIAL_UART_RTS_LO) && defined(SERIAL_UART_RTS_HI)
+ // Buffer state
+ // Empty: RBUF_SPACE == RBUF_SIZE(head==tail)
+ // Last 1 space: RBUF_SPACE == 2
+ // Full: RBUF_SPACE == 1(last cell of rbuf be never used.)
+ #define RBUF_SPACE() (rbuf_head < rbuf_tail ? (rbuf_tail - rbuf_head) : (RBUF_SIZE - rbuf_head + rbuf_tail))
+ // allow to send
+ #define rbuf_check_rts_lo() do { if (RBUF_SPACE() > 2) SERIAL_UART_RTS_LO(); } while (0)
+ // prohibit to send
+ #define rbuf_check_rts_hi() do { if (RBUF_SPACE() <= 2) SERIAL_UART_RTS_HI(); } while (0)
+#else
+ #define rbuf_check_rts_lo()
+ #define rbuf_check_rts_hi()
+#endif
+
+
void serial_init(void)
{
SERIAL_UART_INIT();
data = rbuf[rbuf_tail];
rbuf_tail = (rbuf_tail + 1) % RBUF_SIZE;
+ rbuf_check_rts_lo();
return data;
}
data = rbuf[rbuf_tail];
rbuf_tail = (rbuf_tail + 1) % RBUF_SIZE;
+ rbuf_check_rts_lo();
return data;
}
rbuf[rbuf_head] = SERIAL_UART_DATA;
rbuf_head = next;
}
+ rbuf_check_rts_hi();
}