1
0
This repo is archived. You can view files and clone it, but cannot push or open issues or pull requests.
tmk_keyboard_custom/keyboard/fantastic60/shift_register.c

70 lines
1.6 KiB
C
Raw Normal View History

/*
Copyright 2014 Kai Ryu <kai1103@gmail.com>
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "shift_register.h"
void shift_register_init(void)
{
SR_DDR |= (1<<SR_CLK_BIT | 1<<SR_DATA_BIT | 1<<SR_LATCH_BIT);
SR_PORT &= ~(1<<SR_CLK_BIT | 1<<SR_DATA_BIT | 1<<SR_LATCH_BIT);
}
void shift_register_write_byte(uint8_t byte)
{
uint8_t i = 7;
do {
shift_register_data((byte >> i) & 1);
shift_register_clk();
} while (i--);
shift_register_latch();
}
void shift_register_write_word(uint16_t word)
{
uint8_t i = 15;
do {
shift_register_data((word >> i) & 1);
shift_register_clk();
} while (i--);
shift_register_latch();
}
inline
void shift_register_clk(void)
{
SR_PORT |= (1<<SR_CLK_BIT);
SR_PORT &= ~(1<<SR_CLK_BIT);
}
inline
void shift_register_data(uint8_t bit)
{
if (bit) {
SR_PORT |= (1<<SR_DATA_BIT);
}
else {
SR_PORT &= ~(1<<SR_DATA_BIT);
}
}
inline
void shift_register_latch(void)
{
SR_PORT &= ~(1<<SR_LATCH_BIT);
SR_PORT |= (1<<SR_LATCH_BIT);
}