TIM1 output compare mode on STM32G070
Hi All,
I am trying to generate variable frequency using TIM1 on STM32G070.
I use TIM1 in output compare mode and PC8 as an output for channel 1. Pre-scaler is set to 0 and ARR to divider for whatever frequency I want. When checking registers I see CNT changing between 0 and ARR, as expected but nothing happens at the output. I tried to change PC8 directly to rule out electrical problem - it works fine.
I need just to toggle the PC8, nothing else, but nothing happens... I went through many examples, but very few are relevant for stm32g0 using only CMSIS. Running out of ideas what could be wrong and looking at it for too long, so there is likely something I cannot see.
If anyone has an idea where to look, that would be great
Thanks
// Enable clock for GPIOC
RCC->IOPENR |= RCC_IOPENR_GPIOCEN;
// Enable clock for TIM1
RCC->APBENR2 |= RCC_APBENR2_TIM1EN;
// Disable TIM1
TIM1->CR1 &= ~TIM_CR1_CEN;
// Configure TIM1 for Output Compare, toggle pin
TIM1->SMCR &= ~(TIM_SMCR_SMS | TIM_SMCR_ECE); // internal clock
TIM1->CNT = 0; // Reset counter
TIM1->PSC = 0; // TIM1 pre-scaler = 0;
TIM1->ARR = Get_TIM1_Reload_Val(AF_BW_DEFAULT); // Auto reload value - for default 2700Hz BW (value is 0xEC)
TIM1->CR1 &= ~TIM_CR1_DIR; // Counter direction - UP
TIM1->CR1 &= ~TIM_CR1_CKD_Msk; // Clock division 0
TIM1->CR1 &= ~TIM_CR1_CMS; // Edge aligned mode
TIM1->CR1 &= ~TIM_CR1_OPM; // One pulse mode disabled
TIM1->CR1 &= ~TIM_CR1_ARPE; // ARR preload disabled
// Set output compare mode for Channel 1
TIM1->CCER &= ~TIM_CCER_CC1E; // Disable channel 1
TIM1->CCR1 = 0; // Compare register
TIM1->CCMR1 &= ~TIM_CCMR1_CC1S; // CC1 channel is output
TIM1->CCMR1 &= ~TIM_CCMR1_OC1M_Msk; // Set Channel 1 to output compare toggle mode
TIM1->CCMR1 |= TIM_CCMR1_OC1M_0 | TIM_CCMR1_OC1M_1;
TIM1->CCER |= TIM_CCER_CC1E; // Enable OC channel 1 output
// Configure PC8 as AF2 for TIM1 CH1
GPIOC->MODER &= ~GPIO_MODER_MODE8_Msk;
GPIOC->MODER |= GPIO_MODER_MODE8_1; //pin PC8, alternate function - 10
GPIOC->AFR[1] &= ~GPIO_AFRH_AFSEL8_Msk; //pin PC8, AF2
GPIOC->AFR[1] |= GPIO_AFRH_AFSEL8_1;
GPIOC->OSPEEDR &= ~GPIO_OSPEEDR_OSPEED8; //pin8 increase speed
GPIOC->OSPEEDR |= GPIO_OSPEEDR_OSPEED8_0;
// Enable TIM1
TIM1->CR1 |= TIM_CR1_CEN;