RE: SPI-NOR FS512S incorrect CR3NV[1] value

[Yong Qin <Yong.Qin@xxxxxxxxxxx>]

Hi Boris,

Thanks for pointing this out.

Confirmed with our product team, this is the part of datasheet discrepancy. Since FS512S only has 256KB sector size option, CR3NV[1] is don't care in FS512S and default value is set as 0 in factory.

Column 3 (CR3NV[1]) of table 70 in datasheet will be removed.

For software implementation, if identified the device is FS512S, then checking the combination of CR3NV[3]  & CR1NV[2] is sufficient to decide if the device has top/bottom 4KB sectors, or uniform 256KB sectors.

Thanks,
Yong

-----Original Message-----
From: Boris Brezillon <boris.brezillon@xxxxxxxxxxx>
Sent: Tuesday, December 4, 2018 4:04 AM
To: Yong Qin <Yong.Qin@xxxxxxxxxxx>
Cc: Yogesh Narayan Gaur <yogeshnarayan.gaur@xxxxxxx>; Tudor Ambarus <tudor.ambarus@xxxxxxxxxxxxx>; cyrille.pitchen@xxxxxxxxxx; James Tomasetta <James.Tomasetta@xxxxxxxxxxx>; Jimmy Zhao <jimmy.zhao@xxxxxxx>; linux-mtd@xxxxxxxxxxxxxxxxxxx
Subject: Re: SPI-NOR FS512S incorrect CR3NV[1] value

Hi Yong,

On Tue, 4 Dec 2018 01:37:14 +0000
Yong Qin <Yong.Qin@xxxxxxxxxxx> wrote:

> Hi Boris,
>
> Do you mean the SFDP table?

Sorry, I meant the SMPT (Sector Map Parameter Table) section of the SFDP table. See page 130 of this datasheet [1].

> Can you please share me more detail of what is wrong, i.e., which
> parameter, what is expect value and what you get?

See "Table 70. Sector Map Parameter", CR3NV[1] is always set to one, and when we retrieve this value at runtime we get a 0. Which means we won't find a matching mapid when iterating over the map table, hence the bug reported by Yogesh.

If CR3NV[1] is always 0, then the SMPT should be fixed accordingly:

CR3NV[3]  CR1NV[2]  CR3NV[1]  Index  Value Description
0         0         0         00h    4 kB sectors at bottom with remainder 256 kB sectors
0         1         0         02h    4 kB sectors at top with remainder 256 kB sectors
1         0         0         04h    Uniform 256 kB sectors

Regards,

Boris

[1]http://www.cypress.com/file/216376/download

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