diff options
Diffstat (limited to 'src/ao_timer.c')
-rw-r--r-- | src/ao_timer.c | 85 |
1 files changed, 85 insertions, 0 deletions
diff --git a/src/ao_timer.c b/src/ao_timer.c new file mode 100644 index 00000000..81c3b376 --- /dev/null +++ b/src/ao_timer.c @@ -0,0 +1,85 @@ +/* + * Copyright © 2009 Keith Packard <keithp@keithp.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; version 2 of the License. + * + * 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, write to the Free Software Foundation, Inc., + * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. + */ + +#include "ao.h" + +static volatile __data uint16_t ao_tick_count; + +uint16_t ao_time(void) __critical +{ + return ao_tick_count; +} + +void +ao_delay(uint16_t ticks) +{ + uint16_t until = ao_time() + ticks; + + while ((int16_t) (until - ao_time()) > 0) + ao_sleep(DATA_TO_XDATA(&ao_tick_count)); +} + +#define T1_CLOCK_DIVISOR 8 /* 24e6/8 = 3e6 */ +#define T1_SAMPLE_TIME 30000 /* 3e6/30000 = 100 */ + +volatile __data uint8_t ao_adc_interval = 1; +volatile __data uint8_t ao_adc_count; + +void ao_timer_isr(void) interrupt 9 +{ + ++ao_tick_count; + if (++ao_adc_count == ao_adc_interval) { + ao_adc_count = 0; + ao_adc_poll(); + } + ao_wakeup(DATA_TO_XDATA(&ao_tick_count)); +} + +void +ao_timer_set_adc_interval(uint8_t interval) __critical +{ + ao_adc_interval = interval; + ao_adc_count = 0; +} + +void +ao_timer_init(void) +{ + /* NOTE: This uses a timer only present on cc1111 architecture. */ + + /* disable timer 1 */ + T1CTL = 0; + + /* set the sample rate */ + T1CC0H = T1_SAMPLE_TIME >> 8; + T1CC0L = (uint8_t) T1_SAMPLE_TIME; + + T1CCTL0 = T1CCTL_MODE_COMPARE; + T1CCTL1 = 0; + T1CCTL2 = 0; + + /* clear timer value */ + T1CNTL = 0; + + /* enable overflow interrupt */ + OVFIM = 1; + /* enable timer 1 interrupt */ + T1IE = 1; + + /* enable timer 1 in module mode, dividing by 8 */ + T1CTL = T1CTL_MODE_MODULO | T1CTL_DIV_8; +} |