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AM2634: emmc clock

Part Number: AM2634
Other Parts Discussed in Thread: AM2632

Dear Champs,

My customer would like to check maximum throughput of AM2634 emmc although SW driver is not released yet.

When they checked it in TRM of AM2634, they found 96Mhz clock is supported with 8 data lines for emmc as below.

But, when they checked AM2632 datasheet, they found only 25Mhz or 50Mhz can be supported for emmcsd with 4 datalines.

Can eMMC be attached to AM2634 using SD card high speed mode? I could not find any data for emmc mode described in TRM.

Please help to clarify this and if emmc can be attached to AM2634 and which mode can be used for emmc.

Thanks and Best Regards,

SI.

  • Hi SI., 

    Let me check that out for you. I agree, that looks inconsistent. 

    Thank you,

    -Randy

  • Hi SI. 

    After reviewing the SD Card standard again, I can confirm that the documented maximum clock rates in the AM263x datasheet for SD Card Default and SD Card High Speed are in line with the corresponding modes in the SD Card standard itself. 

    In all cases, users should check the device datasheet for the actually supported modes and clock/data rates supported. The TRM are in some cases written for a superset peripheral usage, but only a subset are supported in the actual device datasheet. We are working to reduce those instances so that the two match. 

    Let me check on that second part though: regarding eMMC compatibility. 

    Thank you,

    -Randy

  • Hi SI. 

    Based on the current TRM, the MMC/SD peripheral can support the MMC standard in Default and High Speed as well under MMC specification 4.3 standard and limited to 4 data line operation. For the full host controller and memory standard check out the MMC standard specification 4.3, in the JESD84-A43 specification.

    Please let me know if that answers your questions here. 

    Thank you,

    -Randy