stm32f1xx_HBL/drv/stk.c
2024-04-28 22:04:10 +02:00

85 lines
1.8 KiB
C

/** @file stk.c
* Module handling the system timer (systick or STK for short)
*
* The module provides functions to configure and use the system timer embedded
* in the cortex m core
*/
//--includes--------------------------------------------------------------------
#include "stk.h"
#include "stk_regs.h"
#include "rcc.h"
//--local definitions-----------------------------------------------------------
static volatile struct STK* regs = (struct STK*)STK_BASE_ADDRESS;
//--local variables-------------------------------------------------------------
static StkCallback callback;
//--public functions------------------------------------------------------------
uint32_t stk_configure(uint32_t period_us, StkCallback cb)
{
stk_reset();
struct RccClocks clocks;
rcc_get_clocks(&clocks);
uint32_t reload = period_us * (clocks.ahb_freq / 1000000 / 8);
if (reload < 1) {
//period is too small, try using the non-prescaled clock
reload = period_us * (clocks.ahb_freq / 1000000);
if (reload < 1) {
//period is still too small
return 1;
}
reg_set(regs->CTRL, STK_CTRL_CLKSOURCE);
}
reg_write(regs->LOAD, STK_LOAD_RELOAD, reload);
reg_set(regs->CTRL, STK_CTRL_TICKINT);
callback = cb;
return 0;
}
void stk_reset(void)
{
reg_reset(regs->CTRL, STK_CTRL_ENABLE);
reg_reset(regs->CTRL, STK_CTRL_TICKINT);
reg_reset(regs->CTRL, STK_CTRL_CLKSOURCE);
reg_reset(regs->CTRL, STK_CTRL_COUNTFLAG);
reg_write(regs->LOAD, STK_LOAD_RELOAD, 0);
reg_write(regs->VAL, STK_VAL_CURRENT, 0);
}
void stk_start(void)
{
reg_set(regs->CTRL, STK_CTRL_ENABLE);
}
void stk_stop(void)
{
reg_reset(regs->CTRL, STK_CTRL_ENABLE);
}
uint32_t stk_read(void)
{
return regs->VAL.word & 0x00FFFFFF;
}
//--local functions-------------------------------------------------------------
void hdr_sys_tick(void)
{
callback();
}