SDCARD slots reading in uBoot

  • Hi everyone,

    I bought 2 evaluation starter kits one for efusA9 and one for efusA7UL modules. I have started efusA9 and I had now relatively good hands on. Now I switched to test the efusA7UL module and discovered some differences when I run uboot and my question is: is it possible to see mmc slots on the evaluaion kit when efusA7UL module is connected?

    I am asking because I did the following scenario:

    I inserted one micro SDCARD and one SDCARD in the corresponding slots on the evaluation kit. If I use efusA9 module on the evaluation kit and from uboot serial console, I can find all the sdcard types even I can see the emmc on the module. I do this using

    1. mm dev 0

    then I switch to card 0, and the same for card 1 and 2.

    If I insert efusA7UL module on the evaluation kit, I can only see the emmc on slot 0 and I can not switch to the other sdcards on the evaluation kit. Which I see a little strange and I do not understand why?

    kind regards,

  • The i.MX6UL/ULL CPU that is used on the efusA7UL only has two SD ports. So the external ports must be shared with internal devices like WLAN and eMMC.

    This means

    • SD_A (Micro SD on SKIT) is only available if WLAN is not equipped
    • SD_B (normal SD on SKIT) is only available if eMMC is not equipped

    In other words, if both, WLAN and eMMC are equipped, then you do not have any external SD signals available anymore. This is due to the limit of two SD ports on the chip.

    The efusA7UL is available in different standard configurations.

    • efusA7UL-V1-LIN: i.MX6ULL 528MHz, 256 MB RAM, 256 MB NAND, 1x Ethernet, Audio
    • efusA7UL-V2-LIN: i.MX6UL 528MHz, 256 MB RAM, 256 MB NAND, 1x Ethernet, RTC
    • efusA7UL-V3-LIN: i.MX6ULL 900MHz, 256 MB RAM, 256 MB NAND, 1x Ethernet, WLAN/BT, Audio
    • efusA7UL-V4-LIN: i.MX6ULL 900MHz, 512 MB RAM, 256 MB NAND, 4 GB eMMC, 2x Ethernet, WLAN/BT, RTC, Audio

    As you said you have eMMC, then this seems to be a V4, with also WLAN on-board. So yes, on this variant no external SD is available. On V1 and V2, you would have both SD ports, on V3 you would have SD_B only.

    If you need a different configuration, then you can have this as a customer specific variant in the series, if your annual order amount (quantity) exceeds a certain limit. For single boards and Starterkits, we only have these standard versions above.

    Your F&S Support Team

    F&S Elektronik Systeme GmbH
    As this is an international forum, please try to post in English.
    Da dies ein internationales Forum ist, bitten wir darum, Beiträge möglichst in Englisch zu verfassen.

    Edited once, last by fs-support_HK ().