i.MX8MM ECSPI maximum transfer size

[sreedhar_appala]

Hi,

I am working with i.MX8MM EVK and 4.19-warrior yocto distribution.

We have interfaced a slave through ECSPI2 pins of i.MX8MM EVK.

From the Reference Manual, the FIFO size of Tx and Rx are 64 words each.

Could you please let me know.

What is the maximum SPI transfer size possible without DMA in ECSPI2 of iMX8MM?

What is the maximum SPI transfer size possible with DMA in ECSPI2 of iMX8MM?

Do you have any test code for validating the transfer size?

Thank you, Sreedhar

[igorpadykov · Accepted solution]

Hi sreedhar_appala

unfortunately I am not aware of test codes for validating the transfer size, for

burst size one can look at driver sources:

https://source.codeaurora.org/external/imx/linux-imx/tree/drivers/spi/spi-imx.c?h=imx_4.19.35_1.1.0

also may be useful:

https://community.nxp.com/t5/i-MX-Processors/imx8-ecspi-Master-Mode-with-SS-CTL-Control/m-p/984674

Best regards
igor

[sreedhar_appala]

Hi igor,

Thank you, I have gone through the spi-imx.c and reference manual ecspix_conreg.

I understand the maximum SPI burst can be 4096 bits = 2^12 = 512 bytes. Same was coded in the spi-imx.c file.

Thank you once again.

Regards, Sreedhar