imxRT1060 USDHC2 CMD pin configuration issue

[ajoao_sousa]

Hi,

My team is developing a board with imxrt1060 and are using the USDHC2 to interface eMMC chip.

At this moment the problem is when we try to set pinx mux for SD_B1_05_USDHC2_CMD pin. The code gets stuck.

After a long time of research, i saw that even in Eval kit, if we call IOMUXC_SetPinMux() for pin IOMUXC_GPIO_SD_B1_05_USDHC2_CMD , the code get stuck.

You try it in using any sample code from SDK.

As an example, you can use hello_world example and in pin_mux.c file, add the following lines:

IOMUXC_SetPinMux(
IOMUXC_GPIO_SD_B1_05_USDHC2_CMD, 
0U); 

IOMUXC_SetPinConfig(
IOMUXC_GPIO_SD_B1_05_USDHC2_CMD, 
0x017089u); 

After executing the first line, code gets stuck.

In Eval kit, that GPIO (GPIO_SD_B1_05) is not connected (0 ohm resistor is not place in HyperFlash interface).

I also attached the hello_world example with this change for MCUXPresso IDE.

[jeremyzhou · Accepted solution]

Hi António Sousa ,

Thank you for your interest in NXP Semiconductor products and
for the opportunity to serve you.
For QSPI Flash as XIP function, to achieve the highest performance, it is recommended to left FLEXSPI_A_DQS（GPIO_SD_B1_05）pin floating and config-sample clock source as 01-loopback from DQS pad mode to achieve max 133MHz Flexspi_clk. Definitely, it's also forbidden to modify the function of GPIO_SD_B1_05.

Hope this is clear.

Have a great day,
TIC

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[ajoao_sousa]

Thank you jeremyzhou.

You are right, are analysing carefully, pin SD_B1_05 is used for FlexSPI_A_DQS pin, so it is not possible to configured that pin for other functionality.

In Evaluation Kit and in our board, DQS is not connected to QSPI Flash.

What I did to use the pin SD_B1_05 for USDHC_CMD was to disable FlexSPI DQS functionality.

In evkmimxrt1060_flexspi_nor_config.c i replaced:

..readSampleClkSrc = kFlexSPIReadSampleClk_LoopbackFromDqsPad

by

.readSampleClkSrc = kFlexSPIReadSampleClk_LoopbackInternally

With this, FlexSPI_A do not use DQS functionality and we can configure SD_B1_05 for other functionalities.

[jeremyzhou]

Hi António Sousa,

Thanks for your reply.
Yes, it's possible to do it, however, the i.MX RT1060 can't run as fast as before. It can only up to 133MHz in SDR Mode, 66MHz in DDR Mode with internal DQS loopback mode.
In my opinion, we don't suggest the developer try this.

Have a great day,
TIC

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[Rick_Bourgeois1]

where can I find this information in documentation?
I based my design on the RT1020 EVAL BOARD.
It has optional combo sensor that is not stuffed.
I assumed it was OK to use pin 26.
Do I re-spin or take Antonio's advice?