Dear Champs,
There are boot fail occurred in my customer's custom board at some time, and we found there was no progress in NAND communication when boot fail occurred.
When boot fail was occurred, booting was successful after reset or power recycling.
We have checked power rails, but could not find any issues in power rails, but found strange things in GMPC_D0 connected with NAND.
customer's boot mode is NAND boot mode(SYSBOOT[4:0] - 10011b)
When boot fail was occurred and checked GPMC_D0 using Oscilloscope, there was no more data communication with NAND after 1st communication as below.
Could you please let me know your idea how we can debug this issue further?
The NAND flash is Micron's MT29F1G08ABAEAWP.
In below picture :
Z1(yellow) - GPMC_D0,
Z2(red) - GPMC_ALE,
Z3(blue) - GPMC_WAIT0,
Z4(green) - GPMC_CLE
* normal case(booting success):
* boot fail:
The time duration are same between first high and low, and it is 164ms.
e.g.
Thanks and Best Regards,
SI.