Tool/software:
Hi all,
I have an issue with AM335x CPU that runs WIN CE OS, let me explain me:
We have a custom board that is dealing with eMMC from micron manufacturer and it is perfectly working. The part number is “MTFC4GACAJCN-1M WT” and according to datasheet it is compliant with “JEDEC/MMC standard version 5.0”
Now, due to component EOL, we need to move to an other chip of an other manufacturer.
The chip chosen was “S40FC004” from Alliance manufacturer. According to datasheet it is e.MMC 5.1 Specification Compatible with backword compatibility with previous e.MMC specification
We compared the datasheet of the 2 different NAND Flash and found out that are pretty same. (They are referring to the same standard, thus they should follow the same guidance)
I'm talking about "JESD84" standard.
The only differences I found out so far are related to:
- Compliance to JEDEC/MMC standard version 5.0-compliant (JEDEC Standard No. JESD84-B50) [old nand] vs compliance to eMMC/JEDEC 5.1 industry standard [alliance nand]
- TAAC [Data Read Access Time 1] : 4h vs TACC [Data Read Access Time 1] : 27h
- DSR support
I did go into the code and found out the bootloader stops in the boot process because I think EMMC does not reply.
I think that stops on one of the first init functions called “MMCIssueIdentify” where the host tries to send the “GO TO IDLE” and then send “OP_COND” code. After that, the emmc does not reply properly, blocking the boot procedure.
Is it possible that the revision specification mismatch causes the fault on recognizing the card? Is it possible that MICRON is a special TI partner and the problem is due to brand?
Any idea?
Thanks,
Marco.
