STM32F7 QSPI Exit Memory Mapped Mode

Posted on January 26, 2017 at 16:20

I tried just re-initializing the peripheral, which worked with the additional step of clearing out FMODE before the re-init.  The code below seems to work:  

/* Stop memory mapped mode */

QUADSPI->CCR &= (~(QUADSPI_CCR_FMODE));

/* ReInitialize QuadSPI ------------------------------------------------------ */

HAL_QSPI_DeInit(&hqspi);

/* ClockPrescaler set to 2, so QSPI clock = 216MHz / (2+1) = 72MHz */

hqspi.Init.ClockPrescaler = 2;

hqspi.Init.FifoThreshold = 4;

hqspi.Init.SampleShifting = QSPI_SAMPLE_SHIFTING_HALFCYCLE;

hqspi.Init.FlashSize = POSITION_VAL(0x1000000) - 1;

hqspi.Init.ChipSelectHighTime = QSPI_CS_HIGH_TIME_2_CYCLE;

hqspi.Init.ClockMode = QSPI_CLOCK_MODE_0;

hqspi.Init.FlashID = QSPI_FLASH_ID_1;

hqspi.Init.DualFlash = QSPI_DUALFLASH_DISABLE;

if (HAL_QSPI_Init(&hqspi) != HAL_OK)

Posted on June 08, 2017 at 18:47

Hi Bobby,

There is no need to completely re-initilize the QSPI preipheral. The memory-mapped mode can be deactivated by changing the FMODE bits in the QUADSPI_CCR register when BUSY is cleared. In Memory-mapped mode, BUSY goes high as soon as the first memory-mapped access occurs. Because of the prefetch operations, BUSY does not fall until there is a timeout, there is an abort, or the peripheral is disabled.

Using the an abort and the HAL library, you can exit out of QSPI memory-mapped mode using the following code:

if

(HAL_QSPI_MemoryMapped(&QSPIHandle, &sCommand, &sMemMappedCfg) != HAL_OK)

{

  Error_Handler();

}

/* ... QSPI in memory-mapped mode ... */

/* Clear busy bit */

HAL_QSPI_Abort(&QSPIHandle);

/* WARNING: Do not make any other memory-mapped access (even using debugger) */

/* Go back to indirect mode */

if (HAL_QSPI_Command(&QSPIHandle, &sCommand, HAL_QPSI_TIMEOUT_DEFAULT_VALUE) != HAL_OK){

  Error_Handler();

}

if

(HAL_QSPI_Receive(&QSPIHandle, aRxBuffer, 1000) != HAL_OK)

{

  Error_Handler();

}

Guillaume