I have a board that connect a Marvell 88WM8686 (WIFI module) to AM3715 through the MMC2 interface in SDIO mode. When the AM3715 MMC controller issues a CMD5 to the WIFI module, it always returns with a timeout (the CTO bit of the status register always set). From the AM3715 datasheet, it states as below:
When I capture the waveform by a logic analyzer, I found that the wifi module generates a response exactly at the 5th clock and ends at 53th clock after the end bit of CMD5. Does it mean this will result in timeout? If yes, the repsonse must be received from 6 clocks to 64 clocks or the timeout error will be generated.
If this is the case, is there any suggestion to fix the problem?
Regards,
Colman
