In FLEXSPI_TransferHandleIRQ(), FLEXSPI_WriteBlocking(), and FLEXSPI_ReadBlocking() input/output from/to RFDR/TFDR is 1 word more than caller specifies in 'size' parameter in some cases

[stephenschwartz]

In FLEXSPI_TransferHandleIRQ(), FLEXSPI_WriteBlocking(), and FLEXSPI_ReadBlocking() input/output from/to RFDR/TFDR is  1 word more than caller specifies in 'size' parameter in certain cases

In attached image, you can see how 'size' parameter, which specifies transfer size in bytes is divided by 4 then increased by 1.

So if caller specifies:

a) Write 2 bytes : 1 word is copied into caller's buffer (Ok, as long as caller allocates in word multiples)

b) Write 3 bytes : 1 word is copied into caller's buffer (Ok, as long as caller allocates in word multiples)

c) Write 4 bytes : 2 words are copied into caller's buffer! (Buffer overflow!)

d) Write 5 bytes : 2 words are copied into caller's buffer! (Ok, as long as caller allocates in word multiples)

Does anyone know why this code does not account for case (c)? 

[kerryzhou]

Hi Stephen,

   Please tell me what the chip, board and sample code you are using?  This is useful to analysis the problem.

Waiting for your reply!

Have a great day,
Kerry

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[stephenschwartz]

Sorry, here is the information:

MIMXRT1052xxxxB  NEW

Build Date: 2018-07-17, Device: MIMXRT1052xxxxB

OS: Windows, Toolchain: MCUXpresso IDE

Components: (None)

SDK Version: KSDK 2.4.1 (2018-06-18)

Sample code is:

uint32_t dest[4];

flexspi_transfer_t flashXfer;

flashXfer.deviceAddress = address;
flashXfer.port = kFLEXSPI_PortA1;
flashXfer.cmdType = kFLEXSPI_Read;
flashXfer.SeqNumber = 1u;
flashXfer.seqIndex = SEQ_IDX_READ_FAST_QUAD;
flashXfer.data = (uint32_t *)dest;
flashXfer.dataSize = sizeof(dest);

FLEXSPI_TransferBlocking(FLEXSPI, &flashXfer)

[kerryzhou]

Hi Stephen，

    I am the LPC and kinetis engineer.

    If you have the I.MX technical issue, please create the question in the I.MX area:

i.MX Processors 

  There will have have the according engineer to help you.

  Besides, next time, when you create the question post, please add the chip part number,  thank you!

Have a great day,
Kerry

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Note: If this post answers your question, please click the Correct Answer button. Thank you!
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