AM4378: NAND flash compatibility check - ISSI IS34MW04G084

faartBOB

Part Number: AM4378

Using the GPMC interface, do you foresee any trouble using this NAND device? ISSI IS34MW04G084

Its specs all look compatible to me, but it is not an ONFI device (to the best of my knowledge).

Reading through the manufacturer's ID definition table and comparing with the AM437x Tech Ref Manual, I see some ID bits that don't quite match up between the two.

The chip's ID codes are (in hex):

Maker code: C8h

Device code: DCh

3rd byte: 90h

4th: 95h

5th: 54h

6th-8th: 7Fh

Thanks in advance

over 6 years ago

0 Biser Gatchev-XID over 6 years ago

TI__Guru**** 393215 points

From the ID codes, this is a 4Gbit memory with x8 organization, 2048kB page size, and 128kB block size. This is consistent with what the memory datasheet states. Note that it has an OOB size of 64bytes, meaning you will need to flash it using BCH8 ECC.

0 faartBOB over 6 years ago in reply to Biser Gatchev-XID

Prodigy 30 points

2051508_IS34ML04G084-TLI_ISSI.pdfThank you, Bisser. Your response gives me confidence.

Your comment about ECC raises another issue, though. the ISSI chip says this in the (attached) datasheet specs:

"ECC Requirement: X8 - 4bit/512Byte" (512B ==sector size)

The AM437x Tech Manual says this:

"The default ECC correction applied is BCH 8 bits per sector using the GPMC and ELM hardware."

It does not appear that AM437x can do ECC at less than 8 bits/sector. Does this discrepancy imply that ECC is not going to work with this ISSI chip?

0 Biser Gatchev-XID over 6 years ago in reply to faartBOB

TI__Guru**** 393215 points

Don't worry, it will work. See Figure 5-15 and Figure 5-16 in the AM437x TRM Rev. H.

0 faartBOB over 6 years ago in reply to Biser Gatchev-XID

Prodigy 30 points

Looking at those figures, It isn't clear to me (because I know next to nothing) that the 4-bit ECC Flash will work with the 8-bit ECC. That said, I'm thankful for your confirmation that they will actually work. Cheers!

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AM4378: NAND flash compatibility check - ISSI IS34MW04G084