Kinetis MicrocontrollersのトピックRe: DSPI EDMA not working with external flash

DSPI EDMA not working with external flash

zahidul3 — Thu, 08 Dec 2022 18:08:09 GMT

When sending data with DSPI EDMA from external flash memory address, the display does not work properly, probably a timing issue since QSPI access is slower than internal flash/RAM.

I am using workaround where if I copy to a RAM buffer before sending to spi dma, then it works fine.

Re: DSPI EDMA not working with external flash

Pavel_Hernandez — Wed, 14 Dec 2022 16:50:07 GMT

Hello,

In order to understand, could you tell me what MCU you have?

Best regards,
Pavel

Re: DSPI EDMA not working with external flash

zahidul3 — Wed, 14 Dec 2022 19:54:50 GMT

We are using the MK82FN256 MCU.

Re: DSPI EDMA not working with external flash

Pavel_Hernandez — Mon, 19 Dec 2022 18:39:54 GMT

Hello,

thanks for the information, could you elaborate further on your issue or the steps to replay this issue?

Best regards,
Pavel

Re: DSPI EDMA not working with external flash

zahidul3 — Sat, 17 Dec 2022 00:15:56 GMT

Using the dspi_edma_b2b_transfer example as a base. If the masterXfer.txData address is from external QSPI memory, if doesn't transfer successfully.

Re: DSPI EDMA not working with external flash

Pavel_Hernandez — Wed, 21 Dec 2022 00:46:10 GMT

Hello,

I review the example and work as expected, maybe you are missing something in your configuration.

Best regards,
Pavel

Re: DSPI EDMA not working with external flash

zahidul3 — Wed, 21 Dec 2022 22:43:35 GMT

Hello,

Can you share your code snippet and what address are you using as the source of the data(txData)?

Re: DSPI EDMA not working with external flash

Pavel_Hernandez — Thu, 22 Dec 2022 02:14:24 GMT

Hello,

Sorry, I do not explain myself, I refer to the original example, the SPI is working as expected, I suggest reviewing your hardware.

Best regards,
Pavel

Re: DSPI EDMA not working with external flash

zahidul3 — Thu, 22 Dec 2022 17:53:19 GMT

The hardware is wired correctly, we believe there might be a limitation in the EDMA SPI DMA drivers that it does not support reading from external QSPI flash taking into account extra delay for reading from external memory.

Re: DSPI EDMA not working with external flash

Pavel_Hernandez — Fri, 23 Dec 2022 19:45:49 GMT

Hello,

There are some devices from NXP that use QuadSPI module, so there are some app notes available that can be useful for QuadSPI development.

Note: Some of the implementation details and features as described in the app notes will be different for K8x, so please use the K8x reference manual for full details.

AN4777, Using the QuadSPI Module on MPC564xS - Application Note (nxp.com)

Quad Serial Peripheral Interface (QuadSPI) Module Updates (nxp.com)

Using the QuadSPI Module on MPC56xxS (nxp.com)

Best regards,
Pavel