PWM + DMA + 100% PWM duty bug, duplicated cycle MCU: STM32F411CEU6.IDE: STM32CUBE IDE 1.5.1Timer1 config:PWM generation mode, CH1+CH2No prescaler, Period=549, Repetition counter = 8DMA: Circular mode, memory->periph, halfword, mem increase CH1+CH2PWM start code:// Ensure 32-bit alignment just in case DMA doesn't like it.
// This Works
__attribute__((aligned(4))) volatile uint16_t PWM_CH1_Data[2] = { 0, 547 };
__attribute__((aligned(4))) volatile uint16_t PWM_CH2_Data[4] = { 0, 100, 200, 547 };
// PWM Duty Higher than (PWM period - 2 ) causes the bug.
// __attribute__((aligned(4))) volatile uint16_t PWM_CH1_Data[2] = { 0, 548 };
void main(void){
// ... HAL initialization, etc
// ...
// Start PWM CH1
HAL_TIM_PWM_Start_DMA(&htim1, TIM_CHANNEL_1, (uint32_t*)&PWM_CH1_Data[0], 2);
// PWM seems to stay busy until the next DMA transfer happens (or repetition counter resets).
while (HAL_TIM_PWM_Start_DMA(&htim1, TIM_CHANNEL_2, (uint32_t*)&PWM_CH2_Data[0], 4) == HAL_BUSY){
asm("nop");
}
// Bo
