eMMC init stalls during boot

[HP]

Hi all,

I have a strange issue that I can't wrap my head around.

I have an eMMC chip connected to a STM32U5G9

The .IOC file is all standard:

with the clock config as follows:

However, when I start a debugging session I get stuck in the init function like so:

It looks almost like the sysTick is not being updated at this point so the whole init just stalls.

If I comment-out the MX_SDMMC1_MMC_Init() the whole system runs as intended (having a touchGFX application that boots right after the inits)

I am running FreeRTOS right now where I think the whole thing should move to ThreadX but the init function should still function as intended, right? For now I am fine with just verifying if the eMMC can initialize.

This is my first time setting up an eMMC so I might have overlooked something basic. Anyone out there with some good insights on this? 

[TDK]

Look at the code where it's paused and why it's stuck there, in HAL_MMC_InitCard. The issue is probably not HAL_Delay directly but rather *why* it's waiting. The generated code probably expects an MMC card as opposed to an eMMC chip. There are subtle differences.

[Saket_Om]

Hello @HP 

Is the MX_SDMMC1_MMC_Init() work fine without FreeRTOS ? 

Are you using the Systick timer as HAL time base?

[HP]

Hello @Saket_Om 

Thanks for your reply - I am using TIM1 as the timebase.

I have created a separate project with just the eMMC and have been running tests on that.

I have removed TouchGFX and FreeRTOS and got the init function to work with first 1-bit MMC and later 8-bit wide MMC. adjusting the clock division to 12 helped.

However, the full system is still not working - Should I change to ThreadX for better support?

[Saket_Om · Accepted solution]

Hello @HP 

You can add FreeRTOS to your test project and check again. The issue may be related to interrupt priorities.

[HP]

Hello @Saket_Om 

I've added the FreeRTOS wit just a simple blink statement. That works just fine. Any suggestions to the interrupt priorities I should try out?

This is the working project:

[HP]

Hellow @Saket_Om 

Thank you for the suggestion!

I changed the priority of the TIM1 to 0 and now the MMC initializes, the RTOS is running and TouchGFX is showing images :)

Thanks!