Hi
We are facing a problem while trying to read data out of QSPI flash in memory mapped mode shortly after programming a page in DMA mode. We see that the read data is corrupted / unexpected altough flash hast he correct data.
Our steps to reproduce the issue :
- Update a data in one sector
- Erasing a sector (4 KBYtes) by
- Entering write mode (HAL_QSPI_Command/QSPI_CMD_WRITE_ENABLE (0x06))
- Send erase command (HAL_QSPI_Command/QSPI_BlockErase_4k (0x20))
- Wait for reading status register (HAL_QSPI_Command/QSPI_CMD_READ_STATUS_REG1 (0x05), HAL_QSPI_Receive) doesn’t have QSPI_REGISTER_WIP set (bit 0).
- Writing just a single page (256Bytes)
- HAL_QSPI_Command_IT /QSPI_CMD_PAGE_PROGRAM (0x02)
- HAL_QSPI_Transmit_DMA (data)
- On transfer complete a callback is triggered from the interrupt
- Enable memory mapped mode and read the data
- Apply Errata suggestions (STM32L471xx Errata sheet , 2.6.5 Wrong data can be read in memory-mapped after an indirect mode operation)
- Enter memory mapped mode HAL_QSPI_MemoryMapped/QSPI_CMD_FAST_READ (0x0B)
- Copy data from a memory mapped region. The red buffer contains unexpected values.
Observations :
- QUADSPI_CCR FMODE indicates indirect write mode before entering memory mapped mode (so according to errata suggestions we are resetting QUADSPI_AR to 0.
- If we add significant delay before going to memory mapped mode (~2000 NOPs), then the red data is correct
- If we don’t use DMA to write, it’s also OK
- In case of failure we see that we receive transfer complete indication before we try to switch to memory mapped mode (also protected by a mutex)
Do you have any suggestions how we can proceed and what we could check next to resolve this problem?
THX, Daniel
PS:
CPU: STM32L4A6VG
STM32L4xx HAL version: 1.8.3 (from STM32Cube_FW_L4_V1.12.0)
