STM32H2723-DMA DAC仅适用于const

Question

在STM32G4中，我能够设置DAC DMA，以便可以使用常规变量(即uint8_t阵列(。然而，当我尝试将代码移植到H723时，DAC DMA将无法工作，除非它使用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补救？我被常数变量卡住了吗？非常感谢。

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, 0);
HAL_NVIC_EnableIRQ(DMA1_Stream5_IRQn);
/* DMAMUX1_OVR_IRQn interrupt configuration */
HAL_NVIC_SetPriority(DMAMUX1_OVR_IRQn, 0, 0);
HAL_NVIC_EnableIRQ(DMAMUX1_OVR_IRQn);
}

在主要功能中：

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);
}

这种设置不起作用，但只要将dac_data1初始化为const uint8_t并预定义它，DMA就可以起作用。

Answer 1

好的，感谢Tom V对不同内存库的深入了解。在我的案例中，dac_data1放在RAM上，在参考手册中也称为DTCMRAM。DTCMRAM对DMA不可访问，但被选择为H7上运行时操作的默认内存位置。需要修改链接器文件(在我的情况下，同时修改…_FLASH.ld和…_RAM.ld(。我更改了.bss、.data和_从CCD_ 9到CCD_ 10的user_heap_。这是直接取自：https://community.st.com/s/article/FAQ-DMA-is-not-working-on-STM32H7-devices