Posted on August 02, 2014 at 10:01Hi All,
New to the STM32 so please bare with me....
I have setup timer4 to generate a sinewave modulated PWM using double buffered DMA and that works very well, I can see my waveform on the pin and it contains the correct data from each of the two buffers.
However, I am trying to update the buffers via the half completed interrupt and I don't seem to be getting any action at all ...
The code that sets up the DMA and the interrupt and the interrupt routine itself follows:
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void DMA_Configuration(void)
{
DMA_InitTypeDef DMA_InitStruct;
NVIC_InitTypeDef NVIC_InitStructure;
// TIM4_UP - DMA1, Channel 2, Stream 6
DMA_InitStruct.DMA_Channel = DMA_Channel_2;
DMA_InitStruct.DMA_BufferSize = PWM_ELEMENTS;
DMA_InitStruct.DMA_DIR = DMA_DIR_MemoryToPeripheral;
DMA_InitStruct.DMA_Mode = DMA_Mode_Circular;
DMA_InitStruct.DMA_FIFOMode = DMA_FIFOMode_Disable;
DMA_InitStruct.DMA_FIFOThreshold = DMA_FIFOThreshold_HalfFull;
DMA_InitStruct.DMA_Memory0BaseAddr = (uint32_t)&PWM_Buffer[0];
DMA_InitStruct.DMA_MemoryBurst = DMA_MemoryBurst_Single;
DMA_InitStruct.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;
DMA_InitStruct.DMA_MemoryInc = DMA_MemoryInc_Enable;
DMA_InitStruct.DMA_PeripheralBaseAddr = (uint32_t)&TIM4->CCR1;
DMA_InitStruct.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;
DMA_InitStruct.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
DMA_InitStruct.DMA_Priority = DMA_Priority_Medium;
DMA_Init(DMA1_Stream6, &DMA_InitStruct);
// Disable stream
DMA_Cmd(DMA1_Stream6, DISABLE);
// Configure double DMA mode.
// This function can be called only when the DMA Stream is disabled.
DMA_DoubleBufferModeConfig(DMA1_Stream6,(uint32_t)&PWM_Buffer2[0],DMA_Memory_0);
// Enable DMA double mode. This function can be called only when the DMA Stream is disabled.
DMA_DoubleBufferModeCmd(DMA1_Stream6, ENABLE);
//!Enable DMA transfer complete interrupt
DMA_ITConfig(DMA1_Stream6, DMA_IT_TC, ENABLE);
NVIC_InitStructure.NVIC_IRQChannel = DMA1_Stream6_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
NVIC_EnableIRQ(DMA1_Stream6_IRQn);
// turning DMA on
DMA_Cmd(DMA1_Stream6, ENABLE);
}
// Interrupt handler for dma transfer 1/2 finished, i.e after one buffer done.
void DMA1_Stream6_IRQHandler(void) {
// Stream6 transfer complete interrupt?
if(DMA_GetITStatus(DMA1_Stream6, DMA_IT_TCIF6)) { // Transfer Complete event
// clear pending interrupt
DMA_ClearITPendingBit(DMA1_Stream6, DMA_IT_TCIF6);
if(DMA_GetCurrentMemoryTarget(DMA1_Stream6)) {
}
else{
}
}
}
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Can anyone help?
EDIT: This is on a STM32F4Discovery Board
