Hi,
Does some one know the SDHC spec. of i.MX31?
There are input setup/hold time of SDHC in data sheet. However, it specify max value of setup/hold time like below.
SDHC input setup MAX 18.5nS, SDHC input hold MAX -11.5nS.
Usually, setup/hold time should be minimum value not MAX.
Could you teach min value of setup/hold time?
Best Regards,
Sugiyama
Hello,
Parameters SD7 and SD8 are defined in the i.MX31 specs with regard to the failing CLK.
SD specs assume rising ones; so min values of SD7 and SD8 are calculated as
CLK period / 2 - SD7/8.
Have a great day,
Yuri
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Hi, Yuri,
Thank you for quick reply.
If it is CLK period/2 - SD7/8, it depend on frequency, but I think setup/hold timing are fixed value.
Does it aware only 25MHz clock and use that value for other frequency?
I calculated them at 25MHz, 40nS cycle
Does it mean setup is 1.5nS min and hold is 8.5nS min?
Does this use for all frequency?
Best Regards,
Sugiyama
Generally You are right: setup is 1.5nS min, hold is 8.5nS min for all frequencies.
~Yuri.