diff options
Diffstat (limited to 'src/lib/systick.c')
-rw-r--r-- | src/lib/systick.c | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/src/lib/systick.c b/src/lib/systick.c new file mode 100644 index 0000000..f328ae0 --- /dev/null +++ b/src/lib/systick.c @@ -0,0 +1,30 @@ +#include "systick.h" + +#define MILLIS_INC 1 + +volatile uint32_t systick_timer_overflow_count = 0; +volatile uint32_t systick_timer_millis = 0; +static uint8_t systick_timer_fract = 0; + +void systick_init(void) { + /* Set the reload counter to tick every 1ms */ + SYSTICK_RELOAD = MAPLE_RELOAD_VAL; + + /* Clock the system timer with the core clock + * and turn it on, interrrupt every 1ms to keep track of millis()*/ + SYSTICK_CSR = SYSTICK_SRC_HCLK | + SYSTICK_ENABLE | + SYSTICK_TICKINT; +} + +void SysTickHandler(void) +{ + uint32_t m = systick_timer_millis; + uint8_t f = systick_timer_fract; + + m += MILLIS_INC; + systick_timer_millis = m; + systick_timer_overflow_count++; +} + + |