82 行
2.4 KiB
C
82 行
2.4 KiB
C
/*
|
|
Copyright 2012 Jun WAKO <wakojun@gmail.com>
|
|
|
|
This software is licensed with a Modified BSD License.
|
|
All of this is supposed to be Free Software, Open Source, DFSG-free,
|
|
GPL-compatible, and OK to use in both free and proprietary applications.
|
|
Additions and corrections to this file are welcome.
|
|
|
|
|
|
Redistribution and use in source and binary forms, with or without
|
|
modification, are permitted provided that the following conditions are met:
|
|
|
|
* Redistributions of source code must retain the above copyright
|
|
notice, this list of conditions and the following disclaimer.
|
|
|
|
* Redistributions in binary form must reproduce the above copyright
|
|
notice, this list of conditions and the following disclaimer in
|
|
the documentation and/or other materials provided with the
|
|
distribution.
|
|
|
|
* Neither the name of the copyright holders nor the names of
|
|
contributors may be used to endorse or promote products derived
|
|
from this software without specific prior written permission.
|
|
|
|
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
|
|
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
|
|
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
|
|
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
|
|
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
|
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
|
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
|
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
|
POSSIBILITY OF SUCH DAMAGE.
|
|
*/
|
|
|
|
#include <stdbool.h>
|
|
#include <avr/io.h>
|
|
#include <avr/interrupt.h>
|
|
#include "x68k.h"
|
|
|
|
|
|
void x68k_init(void)
|
|
{
|
|
KBD_RX_INIT();
|
|
}
|
|
|
|
// RX ring buffer
|
|
#define RBUF_SIZE 8
|
|
static uint8_t rbuf[RBUF_SIZE];
|
|
static uint8_t rbuf_head = 0;
|
|
static uint8_t rbuf_tail = 0;
|
|
|
|
uint8_t x68k_recv(void)
|
|
{
|
|
uint8_t data = 0;
|
|
if (rbuf_head == rbuf_tail) {
|
|
return 0;
|
|
}
|
|
|
|
data = rbuf[rbuf_tail];
|
|
rbuf_tail = (rbuf_tail + 1) % RBUF_SIZE;
|
|
return data;
|
|
}
|
|
|
|
void x68k_send(uint8_t d)
|
|
{
|
|
while (!(UCSR1A&(1<<UDRE1)));
|
|
UDR1 = d;
|
|
}
|
|
|
|
// USART RX complete interrupt
|
|
ISR(KBD_RX_VECT)
|
|
{
|
|
uint8_t next = (rbuf_head + 1) % RBUF_SIZE;
|
|
if (next != rbuf_tail) {
|
|
rbuf[rbuf_head] = KBD_RX_DATA;
|
|
rbuf_head = next;
|
|
}
|
|
}
|