Hi ti:
Because in the process of HS200 pattern recognition, the timing of backward-compatible (400KHz) stage of emmc cannot meet the requirements of emmc5.1 specification.
The emmc cannot be correctly identified in HS200 mode on TDA4 system.
We have developed some countermeasures to this problem.
In hardware:on the CMD line add 12pF capacitance to ground and 33R series resistance.
In software:EMMC uses the following methods for HS200 pattern recognition:
Backward-compatible(400KHz)--HS mode(50MHz)--HS200 mode(200MHz)
Based on the above countermeasures, we performed temporal measurements to meet the protocol standard of EMMC 5.1.
Therefore, I would like to ask you whether mass production can be carried out according to your project experience based on the above countermeasures？
Are there any potential risks?
Looking forward to your reply. Thank you！