iwdg.c

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#include "bsp/iwdg.h"
 
#ifndef HOST_TEST
#include "stm32h7xx.h"
 
#define IWDG_KEY_ENABLE   0xCCCCu
#define IWDG_KEY_REFRESH  0xAAAAu
#define IWDG_KEY_UNLOCK   0x5555u
 
void IWDG_Init(uint8_t prescaler, uint16_t reload) {
    if (prescaler > IWDG_PRESCALER_256) {
        prescaler = IWDG_PRESCALER_256;
    }
    if (reload == 0u) {
        reload = 1u;
    } else if (reload > 0x0FFFu) {
        reload = 0x0FFFu;
    }
 
    /* Unlock PR/RLR for writing. */
    IWDG1->KR = IWDG_KEY_UNLOCK;
 
    /* Wait until any pending write to PR has propagated, then program. */
    while ((IWDG1->SR & IWDG_SR_PVU) != 0u) { }
    IWDG1->PR = prescaler;
 
    /* Same for RLR. */
    while ((IWDG1->SR & IWDG_SR_RVU) != 0u) { }
    IWDG1->RLR = reload;
 
    /* Reload + enable. The first KR=0xAAAA also locks PR/RLR back. */
    IWDG1->KR = IWDG_KEY_REFRESH;
    IWDG1->KR = IWDG_KEY_ENABLE;
}
 
void IWDG_Refresh(void) {
    IWDG1->KR = IWDG_KEY_REFRESH;
}
 
bool IWDG_WasReset(void) {
    return (RCC->RSR & RCC_RSR_IWDG1RSTF) != 0u;
}
 
void IWDG_ClearResetFlag(void) {
    /* RMVF: writing 1 clears all reset reason flags in RCC->RSR. */
    RCC->RSR |= RCC_RSR_RMVF;
}
 
#else /* HOST_TEST — software model so unit tests can exercise the API */
 
#include <stdint.h>
 
static uint8_t  g_iwdg_started;
static uint32_t g_iwdg_refresh_count;
static bool     g_iwdg_was_reset;
 
void IWDG_Init(uint8_t prescaler, uint16_t reload) {
    (void)prescaler;
    (void)reload;
    g_iwdg_started       = 1u;
    g_iwdg_refresh_count = 0u;
}
 
void IWDG_Refresh(void) {
    if (g_iwdg_started != 0u) {
        g_iwdg_refresh_count++;
    }
}
 
bool IWDG_WasReset(void) {
    return g_iwdg_was_reset;
}
 
void IWDG_ClearResetFlag(void) {
    g_iwdg_was_reset = false;
}
 
/* ---- Test-only host hooks (not in iwdg.h; declared in test files) ----- */
 
uint32_t __iwdg_host_refresh_count(void) {
    return g_iwdg_refresh_count;
}
 
void __iwdg_host_set_reset_flag(bool value) {
    g_iwdg_was_reset = value;
}
 
uint8_t __iwdg_host_started(void) {
    return g_iwdg_started;
}
 
void __iwdg_host_reset_state(void) {
    g_iwdg_started       = 0u;
    g_iwdg_refresh_count = 0u;
    g_iwdg_was_reset     = false;
}
 
#endif /* HOST_TEST */