Question
Use DMAR to update CCR1~4 registers
I now need to update the CCR1~CCR3 register at the same time with DMA with DMAR register, I use STM32F103C8T6, I use STM32F10x_StdPeriph_Lib_V3.6.0\Project\STM32F10x_StdPeriph_Examples\TIM\DMABurst example, in the example DMA is Normal mode, I need to keep updating the CCRx registers, so I changed the DMA to Circular mode, but the CCRx registers are not updated as I expected, they are misaligned
#define TIM1_DMAR_ADDRESS ((uint32_t)0x40012C4C) /* TIM ARR (Auto Reload Register) address */
/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
GPIO_InitTypeDef GPIO_InitStructure;
DMA_InitTypeDef DMA_InitStructure;
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_OCInitTypeDef TIM_OCInitStructure;
uint16_t SRC_Buffer[6] = {0x1234, 0x5678, 0xABCD};
int main(void)
{
/* TIM1 and GPIOA clock enable */
RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1 | RCC_APB2Periph_GPIOA, ENABLE);
/* DMA clock enable */
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);
/* GPIOA Configuration: Channel 1 as alternate function push-pull */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);
/* TIM1 DeInit */
TIM_DeInit(TIM1);
/* DMA1 Channel5 Config */
DMA_DeInit(DMA1_Channel5);
DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)TIM1_DMAR_ADDRESS;
DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)SRC_Buffer;
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralDST;
DMA_InitStructure.DMA_BufferSize = 3;
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;
DMA_InitStructure.DMA_Mode = DMA_Mode_Circular;
DMA_InitStructure.DMA_Priority = DMA_Priority_High;
DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;
DMA_Init(DMA1_Channel5, &DMA_InitStructure);
TIM_TimeBaseStructure.TIM_Period = 0xFFFF;
TIM_TimeBaseStructure.TIM_Prescaler = (uint16_t) (SystemCoreClock / 24000000) - 1;
TIM_TimeBaseStructure.TIM_ClockDivision = 0x0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure);
/* TIM Configuration in PWM Mode */
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = 0xFFF;
TIM_OC1Init(TIM1, &TIM_OCInitStructure);
/* TIM1 DMAR Base register and DMA Burst Length Config */
TIM_DMAConfig(TIM1, TIM_DMABase_CCR1, TIM_DMABurstLength_3Transfers);
/* TIM1 DMA Update enable */
TIM_DMACmd(TIM1, TIM_DMA_Update, ENABLE);
/* TIM1 enable */
TIM_Cmd(TIM1, ENABLE);
/* TIM1 PWM Outputs Enable */
TIM_CtrlPWMOutputs(TIM1, ENABLE);
/* DMA1 Channel5 enable */
DMA_Cmd(DMA1_Channel5, ENABLE);
/* Wait until DMA1 Channel5 end of Transfer */
while (!DMA_GetFlagStatus(DMA1_FLAG_TC5))
{
}
/* Infinite loop */
while(1)
{
}
}