TIM3_CH3 on STM32G030

[AKise]

Hello, I try to setup 3 PWM channels on STM32G030K6 MCU, I've selected PA6, PA7 and PB0 as TIM3_CH1, TIM3_CH2 and TIM3_CH3 pins.

Code is generated with STM32Cube and seems to work. Channels 1 and 2 can generate PWM signals. But Channel 3 doesn't generate anything. I have already checked all the settings twice, they are identical. I know that PB0 is shared with PB1, PB2 and PA8, i don't use these pins and have additionally configured them in my code as inputs.

Pin PB0 is functionally Ok, I have tried to configure it as output and it worked.

Does TIM3_CH3 work with this MCU? There is no information about any restrictions in the datasheet.

[Tesla DeLorean]

How is it shared? The K6 is the QFN32 not the SOIC20 part.

PB0 AF1 TIM3_CH3

Show the code

Show the peripheral registers, ie RCC, GPIO and TIM3 related to it

[AKise]

Sorry, it is STM32G030F6 not K6.

Here is the initialisation of TIM3:

static void MX_TIM3_Init(void)
{

  /* USER CODE BEGIN TIM3_Init 0 */

  /* USER CODE END TIM3_Init 0 */

  LL_TIM_InitTypeDef TIM_InitStruct = {0};
  LL_TIM_OC_InitTypeDef TIM_OC_InitStruct = {0};

  LL_GPIO_InitTypeDef GPIO_InitStruct = {0};

  /* Peripheral clock enable */
  LL_APB1_GRP1_EnableClock(LL_APB1_GRP1_PERIPH_TIM3);

  /* USER CODE BEGIN TIM3_Init 1 */

  /* USER CODE END TIM3_Init 1 */
  TIM_InitStruct.Prescaler = 64;
  TIM_InitStruct.CounterMode = LL_TIM_COUNTERMODE_UP;
  TIM_InitStruct.Autoreload = 999;
  TIM_InitStruct.ClockDivision = LL_TIM_CLOCKDIVISION_DIV1;
  LL_TIM_Init(TIM3, &TIM_InitStruct);
  LL_TIM_DisableARRPreload(TIM3);
  LL_TIM_SetClockSource(TIM3, LL_TIM_CLOCKSOURCE_INTERNAL);
  LL_TIM_OC_EnablePreload(TIM3, LL_TIM_CHANNEL_CH1);
  TIM_OC_InitStruct.OCMode = LL_TIM_OCMODE_PWM1;
  TIM_OC_InitStruct.OCState = LL_TIM_OCSTATE_DISABLE;
  TIM_OC_InitStruct.OCNState = LL_TIM_OCSTATE_DISABLE;
  TIM_OC_InitStruct.CompareValue = 0;
  TIM_OC_InitStruct.OCPolarity = LL_TIM_OCPOLARITY_HIGH;
  LL_TIM_OC_Init(TIM3, LL_TIM_CHANNEL_CH1, &TIM_OC_InitStruct);
  LL_TIM_OC_DisableFast(TIM3, LL_TIM_CHANNEL_CH1);
  LL_TIM_OC_EnablePreload(TIM3, LL_TIM_CHANNEL_CH2);
  LL_TIM_OC_Init(TIM3, LL_TIM_CHANNEL_CH2, &TIM_OC_InitStruct);
  LL_TIM_OC_DisableFast(TIM3, LL_TIM_CHANNEL_CH2);
  LL_TIM_OC_EnablePreload(TIM3, LL_TIM_CHANNEL_CH3);
  LL_TIM_OC_Init(TIM3, LL_TIM_CHANNEL_CH3, &TIM_OC_InitStruct);
  LL_TIM_OC_DisableFast(TIM3, LL_TIM_CHANNEL_CH3);
  LL_TIM_SetTriggerOutput(TIM3, LL_TIM_TRGO_RESET);
  LL_TIM_DisableMasterSlaveMode(TIM3);
  /* USER CODE BEGIN TIM3_Init 2 */

  /* USER CODE END TIM3_Init 2 */
  LL_IOP_GRP1_EnableClock(LL_IOP_GRP1_PERIPH_GPIOA);
  LL_IOP_GRP1_EnableClock(LL_IOP_GRP1_PERIPH_GPIOB);
  /**TIM3 GPIO Configuration
  PA6   ------> TIM3_CH1
  PA7   ------> TIM3_CH2
  PB0   ------> TIM3_CH3
  */
  GPIO_InitStruct.Pin = LL_GPIO_PIN_6;
  GPIO_InitStruct.Mode = LL_GPIO_MODE_ALTERNATE;
  GPIO_InitStruct.Speed = LL_GPIO_SPEED_FREQ_LOW;
  GPIO_InitStruct.OutputType = LL_GPIO_OUTPUT_PUSHPULL;
  GPIO_InitStruct.Pull = LL_GPIO_PULL_NO;
  GPIO_InitStruct.Alternate = LL_GPIO_AF_1;
  LL_GPIO_Init(GPIOA, &GPIO_InitStruct);

  GPIO_InitStruct.Pin = LL_GPIO_PIN_7;
  GPIO_InitStruct.Mode = LL_GPIO_MODE_ALTERNATE;
  GPIO_InitStruct.Speed = LL_GPIO_SPEED_FREQ_LOW;
  GPIO_InitStruct.OutputType = LL_GPIO_OUTPUT_PUSHPULL;
  GPIO_InitStruct.Pull = LL_GPIO_PULL_NO;
  GPIO_InitStruct.Alternate = LL_GPIO_AF_1;
  LL_GPIO_Init(GPIOA, &GPIO_InitStruct);

  GPIO_InitStruct.Pin = LL_GPIO_PIN_0;
  GPIO_InitStruct.Mode = LL_GPIO_MODE_ALTERNATE;
  GPIO_InitStruct.Speed = LL_GPIO_SPEED_FREQ_LOW;
  GPIO_InitStruct.OutputType = LL_GPIO_OUTPUT_PUSHPULL;
  GPIO_InitStruct.Pull = LL_GPIO_PULL_NO;
  GPIO_InitStruct.Alternate = LL_GPIO_AF_1;
  LL_GPIO_Init(GPIOB, &GPIO_InitStruct);
}

Here is the initialisation of GPIO:

static void MX_GPIO_Init(void)
{
  LL_GPIO_InitTypeDef GPIO_InitStruct = {0};
/* USER CODE BEGIN MX_GPIO_Init_1 */
/* USER CODE END MX_GPIO_Init_1 */

  /* GPIO Ports Clock Enable */
  LL_IOP_GRP1_EnableClock(LL_IOP_GRP1_PERIPH_GPIOB);
  LL_IOP_GRP1_EnableClock(LL_IOP_GRP1_PERIPH_GPIOA);

  /**/
  LL_GPIO_ResetOutputPin(GPIOA, LL_GPIO_PIN_1);

  /**/
  LL_GPIO_ResetOutputPin(GPIOA, LL_GPIO_PIN_2);

  /**/
  GPIO_InitStruct.Pin = LL_GPIO_PIN_1;
  GPIO_InitStruct.Mode = LL_GPIO_MODE_OUTPUT;
  GPIO_InitStruct.Speed = LL_GPIO_SPEED_FREQ_LOW;
  GPIO_InitStruct.OutputType = LL_GPIO_OUTPUT_PUSHPULL;
  GPIO_InitStruct.Pull = LL_GPIO_PULL_NO;
  LL_GPIO_Init(GPIOA, &GPIO_InitStruct);

  /**/
  GPIO_InitStruct.Pin = LL_GPIO_PIN_2;
  GPIO_InitStruct.Mode = LL_GPIO_MODE_OUTPUT;
  GPIO_InitStruct.Speed = LL_GPIO_SPEED_FREQ_LOW;
  GPIO_InitStruct.OutputType = LL_GPIO_OUTPUT_PUSHPULL;
  GPIO_InitStruct.Pull = LL_GPIO_PULL_NO;
  LL_GPIO_Init(GPIOA, &GPIO_InitStruct);

  /**/
  GPIO_InitStruct.Pin = LL_GPIO_PIN_5;
  GPIO_InitStruct.Mode = LL_GPIO_MODE_INPUT;
  GPIO_InitStruct.Pull = LL_GPIO_PULL_NO;
  LL_GPIO_Init(GPIOA, &GPIO_InitStruct);

/* USER CODE BEGIN MX_GPIO_Init_2 */
  GPIO_InitStruct.Pin = LL_GPIO_PIN_1;
  GPIO_InitStruct.Mode = LL_GPIO_MODE_INPUT;
  GPIO_InitStruct.Pull = LL_GPIO_PULL_NO;
  LL_GPIO_Init(GPIOB, &GPIO_InitStruct);
  GPIO_InitStruct.Pin = LL_GPIO_PIN_2;
  LL_GPIO_Init(GPIOB, &GPIO_InitStruct);
  GPIO_InitStruct.Pin = LL_GPIO_PIN_8;
  LL_GPIO_Init(GPIOA, &GPIO_InitStruct);
/* USER CODE END MX_GPIO_Init_2 */
}

I added all shared pins for PB0 as inputs.

Then I add this to switch PWM outputs on:

LL_TIM_CC_EnableChannel(TIM3, LL_TIM_CHANNEL_CH1);
LL_TIM_CC_EnableChannel(TIM3, LL_TIM_CHANNEL_CH2);
LL_TIM_CC_EnableChannel(TIM3, LL_TIM_CHANNEL_CH3);

And use this one to set PWM value:

LL_TIM_OC_SetCompareCH1(TIM3, xx);
// or
LL_TIM_OC_SetCompareCH2(TIM3, xx);
// or
LL_TIM_OC_SetCompareCH3(TIM3, xx);

I also use PA11 and PA12 for I2C2, PA1 and PA2 as GPIO outputs, PA5 as GPIO input, PB6 and PB7 as USART1, PA0, PA3 and PA4 as SPI2.

RCC->IOPENR = 0x00000003

GPIOA->MODER = 0xEABCA296

GPIOB->MODER = 0xFFFFAFC2

[waclawek.jan · Accepted solution]

Read out and check also GPIOB_AFR[0] and the timer registers.

JW

[AKise]

I've found it. CC3E in TIM3_CCER is not set. I will inverstigate and report it here later.

[AKise]

LL library is just fine for TIM3, there was an error in my source code, I was handling LL_TIM_CHANNEL_CH1, LL_TIM_CHANNEL_CH2 and LL_TIM_CHANNEL_CH3 as uint8, but LL_TIM_CHANNEL_CH3 is 0x100