• State TI Thinks Resolved
  • Locked Locked
  • Replies 4 replies
  • Answers 1 answer
  • Subscribers 100 subscribers
  • Views 1086 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

AM623: Is it possible to adjust SDIO setup time / hold time for CLK & DATA Line

Gibbs Shih
Expert 5355 points
Part Number: AM623
Other Parts Discussed in Thread: CC3300

Hi, TI Expert

Follow this thread discussion,

https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1312725/am623-how-to-set-sdio-clock-data-samping/4998515?tisearch=e2e-sitesearch&keymatch=%25252525252520user%2525252525253A533255#4998515

Customer use AM623x SDIO to connect CC3300, they found SDIO CLK/DATA hold time is too small.

Base on CC3300 spec in HS input, tIH should be 2ns

Ref Spec, p16

https://www.ti.com/lit/ds/symlink/cc3300.pdf?ts=1706922434267&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FCC3300%253FkeyMatch%253DCC3300%2526tisearch%253Dsearch-everything%2526usecase%253DGPN-ALT

But customer's chart as below : 

(blue is clock, green is data)

tIH should be 2ns at least, but customer measure is 0.32ns

so we think it have setup time / hold time risk, even data receiver correct in SW side 

My question is.

1. Does AM62 SW support SDIO setup time / hold time adjust?

2. As far as I know, we could add R&C (Resistance & capacitor) to add some delay, Is the idea possible? Any suggestion?

Many Thanks

Gibbs

  • 0
    TI__Guru 63145 points

    As mentioned in the other E2E thread, the MMCSD host will transition data on the falling edge of CLK when operating in Default Speed Mode or High Speed Mode. Your software should have the MMCSD host configured to operate in High Speed Mode to communicate with the CC3300 device. That does not appear to be the case when looking at the timing CLK to DAT timing relationship shown in the scope capture. It looks like your software has the device configured to operate in UHS-I SDR25 Mode. UHS-I SDR25 mode is only valid for UHS-I cards, not embedded SDIO devices.

    Regards,
    Paul

  • 0 in reply to peaves
    TI__Expert 5355 points

    Hi, Peaves.

    Do you have sampe code for "SDIO high speed setting", example like "linux device tree".

    because I want to double check SDIO works in "high speed mode" for CC3300.

    Many Thanks

    Gibbs

  • 0 in reply to Gibbs Shih
    TI__Guru 63145 points

    I will need to assign this question to someone on the software team.

    Regards,
    Paul

  • 0 in reply to Gibbs Shih
    TI__Guru**** 169301 points

    Hi Gibbs,

    Please refer to sdhci1 or sdhci2 node (depending on which interface the CC3300 device is attached to) in kernel device tree file k3-am62-main.dtsi. Please remove all properties 'ti,otap-del-sel-*' except ti,otap-del-sel-legacy and ti,otap-del-sel-sd-hs. This will ensure the device is only enumerated up to High Speed mode.