问题描述
在 STM32G4 中,我能够设置 DAC DMA,以便我可以使用常规变量(即 uint8_t
数组)。但是,当我尝试将代码移植到 H723 时,DAC DMA 将无法工作,除非它具有在运行时之前设置的常量变量(即 const uint8_t
数组)。我的应用程序需要对数组进行运行时更改。数组的指针初始化似乎不起作用。我想知道是否有办法解决这个问题?我是否坚持使用常量变量?谢谢!
EDIT1:DAC DMA 和 TIMER 的当前设置
static void MX_DAC1_Init(void){
DAC_ChannelConfTypeDef sConfig = {0};
hdac1.Instance = DAC1;
if (HAL_DAC_Init(&hdac1) != HAL_OK){
Error_Handler();
}
sConfig.DAC_SampleAndHold = DAC_SAMPLEANDHOLD_disABLE;
sConfig.DAC_Trigger = DAC_TRIGGER_T15_TRGO;
sConfig.DAC_OutputBuffer = DAC_OUTPUTBUFFER_disABLE;
sConfig.DAC_ConnectOnChipPeripheral = DAC_CHIPCONNECT_ENABLE;
sConfig.DAC_UserTrimming = DAC_TRIMMING_FACTORY;
if (HAL_DAC_ConfigChannel(&hdac1,&sConfig,DAC_CHANNEL_2) != HAL_OK)
{
Error_Handler();
}
}
Timer15 配置:
static void MX_TIM15_Init(void)
{ TIM_ClockConfigTypeDef sClockSourceConfig = {0};
TIM_MasterConfigTypeDef sMasterConfig = {0};
htim15.Instance = TIM15;
htim15.Init.Prescaler = 55-1;
htim15.Init.CounterMode = TIM_COUNTERMODE_UP;
htim15.Init.Period = 10-1;
htim15.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
htim15.Init.RepetitionCounter = 0;
htim15.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_ENABLE;
if (HAL_TIM_Base_Init(&htim15) != HAL_OK)
{
Error_Handler();
}
sClockSourceConfig.ClockSource = TIM_CLOCKSOURCE_INTERNAL;
if (HAL_TIM_ConfigClockSource(&htim15,&sClockSourceConfig) != HAL_OK)
{
Error_Handler();
}
sMasterConfig.MasterOutputTrigger = TIM_TRGO_UPDATE;
sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_disABLE;
if (HAL_TIMEx_MasterConfigSynchronization(&htim15,&sMasterConfig) != HAL_OK)
{
Error_Handler();
}
}
DMA 配置:
static void MX_DMA_Init(void){
__HAL_RCC_DMA1_CLK_ENABLE();
HAL_NVIC_SetPriority(DMA1_Stream5_IRQn,0);
HAL_NVIC_EnableIRQ(DMA1_Stream5_IRQn);
/* DMAMUX1_OVR_IRQn interrupt configuration */
HAL_NVIC_SetPriority(DMAMUX1_OVR_IRQn,0);
HAL_NVIC_EnableIRQ(DMAMUX1_OVR_IRQn);
}
在主函数中:
int main(void){
MX_DAC1_Init();
MX_TIM15_Init();
MX_OPAMP2_Init();
/* USER CODE BEGIN 2 */
set_sine(dac_data1,NUM_DAC_POINTS) //Set a max amplitude uniformly over number of points,dac_data is initialized as uint8_t dac_data1[NUM_DAC_POINTS];
HAL_TIM_Base_Start(&htim15); //Start the timer for DAC DMA Transfer
HAL_DAC_Init(&hdac1);
(HAL_DAC_Start_DMA(&hdac1,DAC_CHANNEL_2,(uint32_t *)dac_data1,NUM_DAC_POINTS,DAC_ALIGN_8B_R);
}
此设置不起作用,但只需将 dac_data1
初始化为 const uint8_t
并对其进行预定义,DMA 即可工作。
解决方法
好的,感谢 Tom V 对不同内存库的洞察。就我而言,dac_data1
放在 RAM
上,在参考手册中也称为 DTCMRAM
。 DTCMRAM
不能被 DMA 访问,但被选为 H7 上运行时操作的默认内存位置。需要修改链接器文件(就我而言,..._FLASH.ld 和..._RAM.ld)。我将 .bss、.data 和 ._user_heap_stack 内存位置从 RAM
更改为 RAM_D1
。这是直接取自:https://community.st.com/s/article/FAQ-DMA-is-not-working-on-STM32H7-devices