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author | 2015-10-27 12:42:30 -0400 | |
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committer | 2015-10-27 12:42:30 -0400 | |
commit | 547da78335298df6666200c6063ac6f1aba312fd (patch) | |
tree | 47df0252ee24b1ecc27b9dd0458c51f20bf088c3 /tmk_core/common/avr/timer.c | |
parent | a766918d5c48204375f4c207b30bbbf1389df14f (diff) | |
parent | fa33719adab1393753312d298b8c365e04e844b9 (diff) | |
download | qmk_firmware-547da78335298df6666200c6063ac6f1aba312fd.tar.gz |
merging tmk
Diffstat (limited to 'tmk_core/common/avr/timer.c')
-rw-r--r-- | tmk_core/common/avr/timer.c | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/tmk_core/common/avr/timer.c b/tmk_core/common/avr/timer.c new file mode 100644 index 000000000..292b41c3a --- /dev/null +++ b/tmk_core/common/avr/timer.c @@ -0,0 +1,117 @@ +/* +Copyright 2011 Jun Wako <wakojun@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 <avr/io.h> +#include <avr/interrupt.h> +#include <stdint.h> +#include "timer_avr.h" +#include "timer.h" + + +// counter resolution 1ms +// NOTE: union { uint32_t timer32; struct { uint16_t dummy; uint16_t timer16; }} +volatile uint32_t timer_count = 0; + +void timer_init(void) +{ + // Timer0 CTC mode + TCCR0A = 0x02; + +#if TIMER_PRESCALER == 1 + TCCR0B = 0x01; +#elif TIMER_PRESCALER == 8 + TCCR0B = 0x02; +#elif TIMER_PRESCALER == 64 + TCCR0B = 0x03; +#elif TIMER_PRESCALER == 256 + TCCR0B = 0x04; +#elif TIMER_PRESCALER == 1024 + TCCR0B = 0x05; +#else +# error "Timer prescaler value is NOT vaild." +#endif + + OCR0A = TIMER_RAW_TOP; + TIMSK0 = (1<<OCIE0A); +} + +inline +void timer_clear(void) +{ + uint8_t sreg = SREG; + cli(); + timer_count = 0; + SREG = sreg; +} + +inline +uint16_t timer_read(void) +{ + uint32_t t; + + uint8_t sreg = SREG; + cli(); + t = timer_count; + SREG = sreg; + + return (t & 0xFFFF); +} + +inline +uint32_t timer_read32(void) +{ + uint32_t t; + + uint8_t sreg = SREG; + cli(); + t = timer_count; + SREG = sreg; + + return t; +} + +inline +uint16_t timer_elapsed(uint16_t last) +{ + uint32_t t; + + uint8_t sreg = SREG; + cli(); + t = timer_count; + SREG = sreg; + + return TIMER_DIFF_16((t & 0xFFFF), last); +} + +inline +uint32_t timer_elapsed32(uint32_t last) +{ + uint32_t t; + + uint8_t sreg = SREG; + cli(); + t = timer_count; + SREG = sreg; + + return TIMER_DIFF_32(t, last); +} + +// excecuted once per 1ms.(excess for just timer count?) +ISR(TIMER0_COMPA_vect) +{ + timer_count++; +} |