Hi,
I'm working on an STM32F303RE project.
So far, only the UART and TIM3 are working properly.
I successfully configured TIM3 in PWM mode on 3 channels, and everything runs as expected. Project is build only on CMSIS libirary.
void clock_config(void)
{
RCC->CR |= RCC_CR_HSION;
while (!(RCC->CR & RCC_CR_HSIRDY));
// RCC->CR |= RCC_CFGR_PLLSRC
RCC->APB1ENR |= RCC_APB1ENR_PWREN;
RCC->CFGR |= RCC_CFGR_HPRE_DIV1;
RCC->CFGR|= RCC_CFGR_PPRE1_DIV2;
//PPL SOURCE MUX
// RCC->CFGR |= RCC_CFGR_PLLMUL9;
RCC->CFGR |= (0x7 << RCC_CFGR_PLLMUL_Pos);
RCC->CR |= RCC_CR_PLLON;
while (!(RCC->CR & RCC_CR_PLLRDY));
RCC->CFGR |= RCC_CFGR_SW_PLL;
while(!(RCC->CFGR & RCC_CFGR_SWS));
RCC -> AHBENR |= RCC_AHBENR_GPIOAEN;
RCC -> AHBENR |= RCC_AHBENR_GPIOBEN;
}
void TIM3_IRQHandler(void)
{
if (TIM3->SR & TIM_SR_CC1IF)
{
TIM3->SR &= ~TIM_SR_CC1IF; // Wyczyść flagę
GPIOA->ODR ^= GPIO_ODR_6; // Przełącz PA6 (D12) z
}
}
void TIM2_IRQHandler(void)
{
//PA0 a0
if (TIM2->SR & TIM_SR_CC1IF)
{
TIM2->SR &= ~TIM_SR_CC1IF; // Wyczyść flagę
GPIOA->ODR ^= GPIO_ODR_0; // Przełącz A0 y
}
}
void TIM4_IRQHandler(void)
{
if (TIM4->SR & TIM_SR_CC1IF)
{
TIM4->SR &= ~TIM_SR_CC1IF; // Wyczyść flagę
GPIOA->ODR ^= GPIO_ODR_11; // Przełącz (PA11) x
}
}
void DIRconfig_x(void)
{
GPIOB -> MODER |= GPIO_MODER_MODER6_0;
GPIOB -> MODER &= ~(GPIO_MODER_MODER6_1);
GPIOB -> OTYPER &= ~(GPIO_OTYPER_OT_6);
GPIOB -> OSPEEDR &= ~(GPIO_OSPEEDER_OSPEEDR6);
GPIOB -> PUPDR &= ~(GPIO_PUPDR_PUPDR6);
}
void configure_z_TIMER3(void)
{
//PA6:D12 CH1
RCC -> APB1ENR |= RCC_APB1ENR_TIM3EN;
TIM3->PSC = 1999; //72mghz 32??
TIM3->ARR = 19; //PA6
TIM3->CR1 |= TIM_CR1_ARPE;
GPIOA->MODER |= GPIO_MODER_MODER6_0;
TIM3->CNT=0;
TIM3->CCMR1 |= (TIM_CCMR1_OC1M_0 | TIM_CCMR1_OC1M_1); //outputcomare config
TIM3->CCER |= TIM_CCER_CC1E;
//interuptTIM3
TIM3 -> DIER |= TIM_DIER_UIE;
TIM3 -> DIER |= TIM_DIER_CC1IE;
NVIC_SetPriority(TIM3_IRQn, 1);
NVIC_EnableIRQ(TIM3_IRQn);
TIM3->CR1|= TIM_CR1_CEN;
}
void configure_y_TIMER2(void)
{
//PA0:A0 AF1
RCC -> APB1ENR |= RCC_APB1ENR_TIM2EN;
TIM2->PSC = 7199; //72mghz 32??
TIM2->ARR = 19;
TIM2->CR1 |= TIM_CR1_ARPE;
GPIOA->MODER |= GPIO_MODER_MODER0_0;
GPIOA->AFR[0] |= ((0x1 << GPIO_AFRL_AFRL0_Pos));
TIM2->CNT=0;
TIM2->CCMR1 |= (TIM_CCMR1_OC1M_0 | TIM_CCMR1_OC1M_1); //outputcomare config
TIM2->CCER |= TIM_CCER_CC1E;
//interuptTIM3
TIM2 -> DIER |= TIM_DIER_UIE;
TIM2 -> DIER |= TIM_DIER_CC1IE;
NVIC_SetPriority(TIM2_IRQn, 3);
NVIC_EnableIRQ(TIM2_IRQn);
TIM2->CR1|= TIM_CR1_CEN;
}
void configure_x_TIMER4(void)
{
//PA11:D12
RCC -> APB1ENR |= RCC_APB1ENR_TIM4EN;
TIM4->PSC = 7199; //72mghz 32??
TIM4->ARR = 19; //PA6
TIM4->CR1 |= TIM_CR1_ARPE;
GPIOA->MODER |= GPIO_MODER_MODER11_0;
TIM1->CNT=0;
TIM4->CCMR1 |= (TIM_CCMR1_OC1M_0 | TIM_CCMR1_OC1M_1); //outputcomare config
TIM4->CCER |= TIM_CCER_CC1E;
//interuptTIM3
TIM4 -> DIER |= TIM_DIER_UIE;
TIM4 -> DIER |= TIM_DIER_CC1IE;
NVIC_SetPriority(TIM4_IRQn, 2);
NVIC_EnableIRQ(TIM4_IRQn);
TIM4->CR1|= TIM_CR1_CEN;
}
int main(void)
{
clock_config();
SysTick_Config(72000000/1);
config_UART();
configure_z_TIMER3();
configure_y_TIMER2();
configure_x_TIMER4();
DIRconfig_x();
USART2->TDR = 'D';
while (!(USART2->ISR & USART_ISR_TXE)) { } // Czekaj na opróżnienie bufora
while (!(USART2->ISR & USART_ISR_TC)) { } // Czekaj na zakończenie transmisji
while(1)
{
}
}
However, when I try to configure other peripherals (for example TIM2, TIM4, or GPIOs on a different port), they do not seem to initialize properly.
When stepping through the debugger, it looks like the code just skips the configuration functions — no registers are updated, no changes take effect.
All peripherals (TIM2, TIM3, TIM4, UART2) are connected to the same APB1 bus.
Summary of symptoms:
TIM3 works correctly in PWM mode and on 3 channels.
UART works correctly.
TIM2, TIM4 configuration fails — registers stay default after supposed initialization.
GPIOs on ports other than A also cannot be configured — the debugger simply skips the initialization code.
I'm wondering if this could be a clock enable issue (RCC settings?) or something else.
But when I configure 3 channels for TIM3, I have to configure also GPIO output for portB and it configures. So I assume it can be, work because off brought clock signal.
Any help would be appreciated!
