about SD card clock control

[junxliu]

sd card clock shut down

I am designing a SD host controller, I have a question about the clock control function. Dose any one known the SD clock can be shut down in the period of the data transfer? I can affirm the clock can be shut down between two block data transfer!

 

[vibhute_r_p]

No ..clock can not be shut down during data transfer.

Regards,
Ram

 

[josesmn]

No ..clock can not be shut down during data transfer.

Regards,
Ram

If you want to make the card wait for data, you can shut down the clock. For eg. your controller have only 256 byte buffer and if the data to transfer is 512 bytes, you can sent the first 256 bytes to card and then shut the clock, get next 256 byte from host driver and again start clock and sent data.