topic FLEXSPI eDMA read issue: half data loss in i.MX RT Crossover MCUs

FLEXSPI eDMA read issue: half data loss

aleksejshch — Mon, 27 Mar 2023 10:13:45 GMT

Hi,

I'm debugging QSPI between R1166 (Master) and FPGA (Slave).

I use MCUXpresso IDE with SDK: SDK_2_13_0_MIMXRT1160-EVK (board - MIMXRT1160-EVK).

I use modified example (SDK_2_13_0_MIMXRT1160-EVK/boards/evkmimxrt1160/driver_examples/flexspi/nor/edma_transfer/cm7/). Modifications: changed FLEXSPI1 to FLEXSPI2, created my own LUT.

Transactions: write buffer (128 bytes), then read buffer (128 bytes). Using logic analyzer, I can see that data is correct. Also, reading via AHB bus works properly. But call of function flexspi_nor_read_data() returns broken data. Data should be an increment from 0 to 0x7F, but really looks like 8 bytes added to buffer, 8 lost, 8 added, 8 lost, etc. So, second half of buffer is trash.

Below is a screenshot from log, where 1-st buffer is data received from flexspi_nor_read_data(), and 2-nd - reading via AHB (copy from FlexSPI2_AMBA_BASE):

s_fpga_read_buffer is located in non-cacheble section.

Could you please help me where I can search bug? Is it DMA side or FLEXSPI?

Re: FLEXSPI eDMA read issue: half data loss

aleksejshch — Mon, 27 Mar 2023 12:58:38 GMT

In SDK file fsl_flexspi_edma.c in function FLEXSPI_TransferEDMA() I found that for case "else if (xfer->cmdType == kFLEXSPI_Read)"

I see next call:

EDMA_SetModulo(handle->txDmaHandle->base, handle->txDmaHandle->channel, (edma_modulo_t)power,
kEDMA_ModuloDisable);

But I think it should be:

EDMA_SetModulo(handle->rxDmaHandle->base, handle->rxDmaHandle->channel, (edma_modulo_t)power,
kEDMA_ModuloDisable);

At least when I changed it, I can see expected values in receive buffer.

Is it correct? Is it SDK mistake?

Re: FLEXSPI eDMA read issue: half data loss

Hui_Ma — Tue, 04 Apr 2023 08:17:55 GMT

Hi,

Thank you for the help.

I will report this SDK software driver bug to SDK software team. Thanks again.

best regards,

Mike