Using Unused SEMC Pins as GPIO

[sanjana291]

Dear NXP Community,

In my application, I am not using the following SEMC (SDRAM) pins:

• IOMUXC_GPIO_EMC_B1_40_SEMC_RDY
• IOMUXC_GPIO_EMC_B1_41_SEMC_CSX00
• IOMUXC_GPIO_EMC_B2_18_SEMC_DQS4

Due to limited GPIO availability on my board, I would like to repurpose these unused SEMC pins as general-purpose I/O (both input and output).

Question:
Is it permissible to configure these SEMC pins as GPIO if the SEMC interface is not in use? Could you confirm whether this approach is valid and will not interfere with system operation?

Thank you for your guidance.

Best regards,
Sanjana S.

[EdwinHz]

Hi @sanjana291,

If the SEMC module is completely unused, then you can use those pins as GPIO with no issues.

[sanjana291]

I’m using SDRAM with the SEMC module enabled in my application. In this case, can I still use the following SEMC pins as GPIO (both input and output), since some other GPIO pins are not available?

[EdwinHz]

Hi @sanjana291,

If SEMC is already being used for an SDRAM, all SEMC pins should be connected to it as mentioned on the MIMXRT1170HDUG. This is because some SEMC pins cannot be used as GPIO if SEMC is enabled.