diff options
author | tmk <nobody@nowhere> | 2012-06-11 10:53:02 +0900 |
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committer | tmk <nobody@nowhere> | 2012-06-11 10:53:02 +0900 |
commit | 62d1ebb91c7b381ce3d88aad9ee0b03bea9fce26 (patch) | |
tree | 6b10864a310f611187e1b61102da7da1db1d2e29 /protocol/x68k.c | |
parent | 225de7a847a511d004bf909b1334e19497cf2f9d (diff) | |
parent | 81706d1130fdc3c0d6d110f4d8665c47ffd7fb59 (diff) |
Merge branch 'newdir'
Diffstat (limited to 'protocol/x68k.c')
-rw-r--r-- | protocol/x68k.c | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/protocol/x68k.c b/protocol/x68k.c new file mode 100644 index 0000000000..d17af51cc2 --- /dev/null +++ b/protocol/x68k.c @@ -0,0 +1,75 @@ +/* +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; +} + +// 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; + } +} |