diff options
| -rw-r--r-- | libmaple/systick.h | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/libmaple/systick.h b/libmaple/systick.h index dfe3429..a589bc5 100644 --- a/libmaple/systick.h +++ b/libmaple/systick.h @@ -76,20 +76,33 @@ typedef struct systick_reg_map { extern volatile uint32 systick_uptime_millis; /** - * + * @brief Returns the system uptime, in milliseconds. */ static inline uint32 systick_uptime(void) { return systick_uptime_millis; } + void systick_init(uint32 reload_val); void systick_disable(); void systick_enable(); +/** + * @brief Returns the current value of the SysTick counter. + */ static inline uint32 systick_get_count(void) { return SYSTICK_BASE->CNT; } +/** + * @brief Check for underflow. + * + * This function returns 1 if the SysTick timer has counter to 0 since + * the last time it was called. However, any reads of any part of the + * SysTick Control and Status Register SYSTICK_BASE->CSR will + * interfere with this functionality. See the ARM Cortex M3 Technical + * Reference Manual for more details (e.g. Table 8-3 in revision r1p1). + */ static inline uint32 systick_check_underflow(void) { return SYSTICK_BASE->CSR & SYSTICK_CSR_COUNTFLAG; } |