STM32L451 - eMMC CRC error at init when reading ExtCSD

[thinkerfox_seb]

Hello,

I'm working on a custom board with a STM32L451 and an emmc (THGBMNG5D1LBAIL - 4gb). At initialization (using the HAL generated init functions), I get the CID and CSD but not the ExtCSD. I get a CRC error (in polled mode as well as in DMA mode). Since it is at the initialization, I cannot change a lot of settings...(main clock is at 80Mhz but at lower clock value I get the same issue) I've seen that I need to set "half-word" in the DMA settings in order to have a same alignment as in polled mode...But obviously doesn't help since I get the same error in both cases... (with or without misalignment)

Do you have any idea on what direction I could look at?

Thanks a lot!

clock config:

SDMMC settings:

[Saket_Om]

Hello @thinkerfox_seb 

Could you please share your code and give more details about the issue. Mybe you can share register content before and after the problem occur. 

---

@thinkerfox_seb wrote:

Hello,

I'm working on a custom board with a STM32L451 and an emmc (THGBMNG5D1LBAIL - 4gb). At initialization (using the HAL generated init functions), I get the CID and CSD but not the ExtCSD. I get a CRC error (in polled mode as well as in DMA mode). Since it is at the initialization,

---

It is not clear; the issue occurs at initialisation or at polling or DMA process?