STM32GO controller PWM Generation issue

[Denial1]

Hello All

Current Device setup:-

NUCLEO-G071RB Eval board

STM32CubeMX settings please find the attached screenshots.

• I'm trying to generate PWM signal using [ TIM3 channel 3] in NUCLEO-G071RB Eval board.

• Time period is 28 microseconds and width are 3 microseconds.

• As you can see in the below [image 1 ]only the first pulse is different or corrupted, which gives 32 microseconds time period and width are 7 microseconds .

• From the second pulse , we are able to get the expected pulse as shown below [image 2] Time period is 28 microseconds and width are 3 microseconds.

• Same behaviour is observed in STM32Cube_FW_G0_V1.6.0 package code, given by STM32 Timer PWM output example code.

Please provide the solution to resolve this issue.

Image 1:-

Image 2:-

[Sarra.S · Accepted solution]

Hello @waclawek.jan, @Denial1, @TDK, 

This behavior is now noted in Readme files of all HAL TIM examples calling HAL_TIM_PWM_ConfigChannel() with the output channel configured in PWM1 mode:

TIM_6Steps, 

TIM_Asymetric, 

TIM_CascadeSynchro,

TIM_Combined,

TIM_ComplementarySignals,

TIM_Dithering,

TIM_DMA,

TIM_DMABurst,

TIM_ParallelSynchro,

TIM_PrescalerSelection,

TIM_PWMOutput.

The note is the following: 

In this examples, the output channel is configured in PWM1 mode meaning that in up-counting mode, channel 1 is active as long as TIMx_CNT < TIMx_CCR1. As, in the function HAL_TIM_PWM_Start* function, the output channel is enabled prior enabling the timer's counter a timing difference might be observed on the first generated PWM. This difference corresponds to the delay - in term of number of CPU cycles - between the channel enable and the counter enable in the HAL_TIM_PWM_Start* function.

Thank you!