Dear all,
Our customer uses eMMC5.0 device. ( IMX6D , android 5.0 , sandisk emmc sdin9dw4-16g )
we already modified android source ( mmc.c file : card->ext_csd.rev )
first sample is ok , mfgtool downloading is ok , android boot is ok
our customer made almost 1k board
1st : 360 ea board : 27 ea board has problem
2nd : 300 ea board : 6 ea board has problem , customer changed SMT factory
3rd : 500 ea board : around 10 ea
board didn't boot ( uboot message is not shown ) , not always can't boot , sometime board can boot ok
approximately 1 time can't boot ( total 10 times tried ) , but boot fail is not regular ( randomly )
1 bad cpu reball to normal board --> not boot
2 new cpu swapped on problem board -> OK boot
booting process
my Question
is there any compatibility with emmc 5.0 device ? they use sandisk .
scope picture
1 is POR , 2 is SD4_DATA0
abnormal boot
normal boot
May I have advice?
Best Regards,
Hi Allen
emmc5.0 should work fine as boot ROM will fall back to the eMMC4.4
standard when a emmc5.0 capable device is detected. Please try to extend POR
up to 0.8-sec, considering ERR009678
http://cache.freescale.com/files/32bit/doc/errata/IMX6DQCE.pdf
Also one can check why in abnormal boot case there is toggling SD4_DATA0 before POR
release - this may be power-up issue or bad power for eMMC (check its reset) or from
some external attached device. Check power supplies with oscilloscope, paying attention
to XX_CAP voltages. Use guidelines from i.MX6 System Development User’s Guide (rev.2, 10/2016)
http://cache.freescale.com/files/32bit/doc/user_guide/IMX6DQ6SDLHDG.pdf
Best regards
igor
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