EC200UCNAC: eMMC mount/fdisk failure

Technical Subjects Driver
1

Dear Quectel Support Team,

I am working on an EC200-based design using an external eMMC (Phison MEM5-S series, eMMC 5.1 pSLC).

Hardware details:
Module: EC200
eMMC: Phison MEM5-S (pSLC, eMMC 5.1)
Bus width: 4-bit
eMMC reset connected to GPIO30
Pin number details:
SDIO1_DATA3 28
SDIO1_DATA2 29
SDIO1_DATA1 30
SDIO1_DATA0 31
SDIO1_CLK 32
SDIO1_CMD 33
MODE_FUNC 0

Software details:
Using Quectel SDMMC APIs
Filesystem mode (FAT), not raw block access
Calling ql_sdmmc_set_dev_cfg() with eMMC-only, 4-bit, with default settings
Registered power/reset callback using ql_sdmmc_register_power_reset_cb() to toggle GPIO30

Issue:
ql_sdmmc_mount() fails fails with QL_SDMMC_CREATE_ERR
ql_sdmmc_fdisk_ex() fails with QL_SDMMC_CREATE_ERR

How can I successfully mount ?

Thank You.

2

Dear @Roopa,

If ql_sdmmc_mount() and ql_sdmmc_fdisk_ex() both fail with QL_SDMMC_CREATE_ERR, this usually indicates the SDMMC device instance is not being created/enumerated (pinmux/power/reset/bus/clock) rather than a FAT issue.

Please verify the SDIO1 pins are correctly muxed to SDMMC function and ensure CMD/DAT pull-ups and VCC/VCCQ levels match your eMMC. Also confirm the eMMC reset (GPIO30) sequence: hold reset low after power is stable, release, wait a few ms, then run SDMMC init.
For isolation, please test with 1-bit + low clock first; if 1-bit works but 4-bit fails, it points to DAT1–DAT3 wiring/signal/pull-ups.

After successful enumeration, the expected order is: fdisk_ex() → format (mkfs) → mount().

To pinpoint the root cause, please share the return codes/logs for ql_sdmmc_set_dev_cfg(), ql_sdmmc_register_power_reset_cb(), and any SDMMC init/open API, plus any SDMMC debug logs during initialization.

Best Regards,
Aghelan