STM32F7 QSPI Exit Memory Mapped Mode

[Bobby Hayes]

Posted on January 26, 2017 at 16:00

Hi,

The QSPI peripheral in the STM32F7 is wonderful.  Nice job ST!

One question:  Is there any way to exit memory mapped mode and go back to indirect RX/TX through the HAL driver?

Thanks!

Bobby

[Bobby Hayes]

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)

[Nesrine M_O]

Posted on January 26, 2017 at 16:57

Hi,

Refer also to this application note  

http://www.st.com/content/ccc/resource/technical/document/application_note/group0/b0/7e/46/a8/5e/c1/48/01/DM00227538/files/DM00227538.pdf/jcr:content/translations/en.DM00227538.pdf

, it may help you.

-Nesrine-

[Gln]

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

[Matteo Campese]

Posted on June 05, 2018 at 18:20

Hi Guillaume,

I have some problem with the Abort command: I'm able to use HAL Abort function only when the 'OSPI Timeout Activation' is disable and at least one read request is done on the mapped memory.

If I try to use the Abort function without the above conditions, the function hangs waiting for the Transmission Complete flag to be set:

/* Wait until the transfer complete flag is set to go back in idle state */

status = OSPI_WaitFlagStateUntilTimeout(hospi, HAL_OSPI_FLAG_TC, SET, tickstart, hospi->Timeout);

and after the Timeout (5 seconds default timeout) the function returns

HAL_ERROR

.

Many Thanks!

Matteo