Posted on March 18, 2018 at 03:02Hi Clive, I was wondering if you managed to get the SDMMC working in DMA mode ? I'm following the ST example (uSD_DMA_Standalone) but only polling mode works for me. I'm not sure if I'm reading the datasheet right (Table 1. Bus-master-to-bus-slave interconnect) but it seems SDMMC has access to AXI SRAM only ? I thought the MDMA managed the transfer (which has access to all RAMs I think) I noticed that if I use an SRAM1 buffer I get some error (HAL_SD_ErrorCallback is called) if I use an AXI SRAM buffer instead I don't get an error, but ReadBlocks_DMA timesout (HAL_SD_TxCpltCallback is never called). Here's my code it's a bit messy, sorry for that, am I missing anything obvious ?
void HAL_SD_MspInit(SD_HandleTypeDef *hsd)
{
// MDMA controller clock enable
__HAL_RCC_MDMA_CLK_ENABLE();
// Enable SDMMC clock
__HAL_RCC_SDMMC1_CLK_ENABLE()
__HAL_RCC_SDMMC1_FORCE_RESET();
__HAL_RCC_SDMMC1_RELEASE_RESET();
// NVIC configuration for SDMMC interrupts
HAL_NVIC_SetPriority(SDMMC_IRQn, IRQ_PRI_SDMMC, IRQ_SUBPRI_SDMMC);
HAL_NVIC_EnableIRQ(SDMMC_IRQn);
// GPIOs have already been initialised by sdcard_init
}
// SD device interface configuration
sd_handle.Instance = SDMMC1;
sd_handle.Init.ClockEdge = SDMMC_CLOCK_EDGE_RISING;
sd_handle.Init.ClockPowerSave = SDMMC_CLOCK_POWER_SAVE_ENABLE;
sd_handle.Init.BusWide = SDMMC_BUS_WIDE_4B;
sd_handle.Init.HardwareFlowControl = SDMMC_HARDWARE_FLOW_CONTROL_DISABLE;
sd_handle.Init.ClockDiv = SDMMC_TRANSFER_CLK_DIV;
// init the SD interface, with retry if it's not ready yet
for (int retry = 10; HAL_SD_Init(&sd_handle) != HAL_OK; retry--) {
if (retry == 0) {
led_flash_error(1);
goto error;
}
HAL_Delay(10);
}
Later I call HAL_SD_ReadBlocks_DMA() and wait for WriteStaus == 0.. But this is never called using AXI buffer:
void HAL_SD_TxCpltCallback(SD_HandleTypeDef *hsd)
{
WriteStatus = 1;
}
And this gets called if I use SRAM1 buffer:
void HAL_SD_ErrorCallback(SD_HandleTypeDef *hsd)
{
led_flash_error(1);
}
