In this case, the reason can not be determined. All the algorithms of EMMC are universal and can not work through ISP. In general, it is reason of the main board.
power on the motherboard, and check the RST_ N of EMMC Whether RST_N pin is high level, if RST_ N is 0. It is necessary to pull up the pin, otherwise EMMC will not work. 作者: STALKER_71 时间: 2020-11-29 17:36
I solder directly to the emmc chip. But it not detect. I tried on three single chips. I will try to pull up RST_n to high level.作者: admin 时间: 2020-12-1 17:00
回复 3#STALKER_71 it maybe VCCQ Problem . if this chip not supported by VCCQ=3.3V. you must use VCCQ=1.8V. and you need an external 1.8V power. 作者: STALKER_71 时间: 2020-12-1 21:22
Yes I applied 1.8 with external power. Pull Up RST_n dont change anything. Chip dont detect. When i add pull up resistors 22k to cmd and dat0. Chip detect, but with wrong csd and sid, and dont read and erase. I cant test it with adapter BGA221 because i cant find it to buy.作者: STALKER_71 时间: 2020-12-17 22:58
I tested many samsung and hynix chip bga221 EMMC v5.1 and all have detect problem. Only EMMC v5.1 have this problem. All lower version detect and read normal. Maybe this bug of programmer software.作者: admin 时间: 2020-12-19 11:25