STM32F107 timers problem

[freya17365]

Hi to all,

I hope this is the right place where asking to.

Anyway in my custom board I use four timers: SysTick, RTC, TIM6 (DAC) and TIM3 (PWM).

I wnted to add a new timer (I tryed TIM7 and TIM2), but it wouldn't work and I discovered that neither TIM3 and TIM6 work, but them where working time ago.

What can check and do?

Hereafter I add TIM6 (once working) and TIM7 configuration:

// TIM6

   DAC->CR &= ~(DAC_CR_DMAEN1 | DAC_CR_MAMP1 | DAC_CR_WAVE1 | DAC_CR_TSEL1 | DAC_CR_TEN1 | DAC_CR_BOFF1 | DAC_CR_EN1);      //Clear channel 1 CR register ->timer6 enabled

   DAC->CR |= DAC_CR_DMAEN1 | DAC_CR_TEN1 | DAC_CR_EN1;      //SW trigger

   if(!(RCC->APB1ENR & RCC_APB1ENR_TIM6EN)) RCC->APB1ENR |= RCC_APB1ENR_TIM6EN;      // Enable TIM6 clock

   TIM6->CR1 = 0x0000;   // Reset CR1 (Edge mode | Up counter | Continous mode)

   TIM6->CR2 = 0x0000;   // Reset CR2

   TIM6->CR2 |= TIM_CR2_MMS_1;                           // The update event is selected as a trigger output (TRGO).

   TIM6->DIER |= TIM_DIER_UIE | TIM_DIER_UDE;   //Enable interrupt | Enable DMA request

   TIM6->EGR = TIM_EGR_UG;                                 // Re-initializes the timer counter and generates an update of the registers

   TIM6->PSC = 35;                  // Prescaler

   TIM6->ARR = 1000;               // Auto reload register (frequency)

   TIM6->CNT = 0;                  // Counter (freq = SYSCLOCK/PSC/CNT)

   TIM6->SMCR &= ~7;

   TIM6->CR1 |= TIM_CR1_CEN;   // Enable TIM6

   if(!(RCC->AHBENR & RCC_AHBENR_DMA2EN)) RCC->AHBENR |= RCC_AHBENR_DMA2EN;      // Enable DMA2 clock

   DMA2_Channel3->CCR = 0x00000000;      // Reset register

//   DMA2_Channel3->CCR |= DMA_CCR_MSIZE_0 | DMA_CCR_PSIZE_0 | DMA_CCR_MINC | DMA_CCR_CIRC | DMA_CCR_DIR;      // size 16 bit both mem and periph | mem increment | circular | up

   DMA2_Channel3->CCR |= DMA_CCR_MSIZE_0 | DMA_CCR_PSIZE_0 | DMA_CCR_MINC | DMA_CCR_CIRC | DMA_CCR_DIR | DMA_CCR_TCIE;      // size 16 bit both mem and periph | mem increment | circular | up | Transfer compl int

   DMA2_Channel3->CNDTR = 70;   // Data to be transfered

   DMA2_Channel3->CPAR = (uint32_t) &(DAC->DHR12R1);   // Peripheral address

   DMA2_Channel3->CMAR = (uint32_t) &sen[0];   // Memory address

   DMA2_Channel3->CCR |= DMA_CCR_EN;      // Enable

//TIM7

   if(!(RCC->APB1ENR & RCC_APB1ENR_TIM7EN)) RCC->APB1ENR |= RCC_APB1ENR_TIM7EN;      // Enable TIM7 clock

   TIM7->CR1 = 0x0000;   // Reset CR1 (Edge mode | Up counter | Continous mode)

   TIM7->CR2 = 0x0000;   // Reset CR2

   TIM7->DIER |= TIM_DIER_UIE;   //Enable interrupt

   TIM7->EGR |= TIM_EGR_UG;                                 // Re-initializes the timer counter and generates an update of the registers

//   TIM7->EGR &= ~TIM_EGR_UG;                                 // Re-initializes the timer counter and generates an update of the registers

   TIM7->PSC = 72;                  // Prescaler

   TIM7->ARR = 100;               // Auto reload register (frequency)

   TIM7->CNT = 10;                  // (freq = SYSCLOCK/PSC/CNT)

   TIM7->CR1 |= TIM_CR1_CEN;   // Enable TIM7

Thank you

Freya

[TDK]

View the register values and ensure they're what you expect. What does "it wouldn't work" mean exactly?

>   TIM7->CNT = 10;                  // (freq = SYSCLOCK/PSC/CNT)

Not sure what this means, but the update interval is (timer clock) / (PSC + 1) / (ARR + 1). The timer tick interval is (timer clock) / (PSC + 1).

[freya17365]

"it woudn't work" means that when I coded PWM and DAC routines they worked well. Then I coded other parts of the project so I didn't check if PWM and DAC continued to work.

Now I decided toset a timer and interrupt routine to launch acquiredata() function to set a more precise timing. When I "cut and paste" timer initialization, I discovered it wouldn't work and so did the others (only SysTick and RTC continue working).

[TDK]

Read out the timer registers in the working state and compare them to the not working state.

If it's the same code in both cases, it's unlikely the code is the issue here.

[Tesla DeLorean]

Watch for the Hazard of enabling the clock and immediately touching the peripheral registers.

Enable all the clocks you want EARLY, or put in a while() loop rather than the if () you're using.

[freya17365]

Indeed I did not think there could be such a problem.

Anyway I put all clock enable in an ClockInit() function at very initialization beginning and now it seems to work properly.

Thank you

Freya