TDA4VM-Q1: Why is SD 3V3 to first CMD 5 seconds before initializing SD card?

Hi Cloud,

I have assigned the corresponding expert regarding this issue.

Regards

Gokul

Thanks a lot, please alao confirm below question ASAP.

• If card busy happen, why will SD 3V3 power reset 3 cycles then turn off during SD initialization ??

Hi Cloud,

Cloud Peng said:

Please help to explain why CMD ready to send must be 5 seconds.

Can we shorten this timing 5 to 3 seconds?

Please share where you find the requirement for CMD ready to send in 5s. Also what is the reasoning for wanting to shorten timing to 3s?

This will help to better explain why we have the requirements and if they can be changed or not.

Best Regards,

Matt

Hi Matt:

We measure 5 seconds in SDK8.0 Linux system.

Can you explain why original setting is 5 seconds? Is it must?

Now SW RD optimize to fast bootup in UI within 8 seconds. EE measure timing 5 seconds will shorten to 3 seconds, will it have side-effect in self-initialization of SD card?

HI Cloud,

Cloud Peng said:

We measure 5 seconds in SDK8.0 Linux system.

Sorry for the late reply.

Can you attach the code/line where you found the 5 seconds delay ?

Regards

Gokul