[DM36x] how to support new nand device

Hayden Kim

Genius 15580 points

There is a new nand device from Samsung, "K9F1G08D0D".

It is next generation of "K9F1G08X0C".

With "K9F1G08X0C"(C-type), DM368 working with no issue.

But change to "K9F1G08D0D"(D-type), data cannot be read, only "bad block" error messages are shown.

I attached both C-type and D-type data sheet. Please check how to use "D-type" nand device.

over 13 years ago

0 Renjith Thomas over 13 years ago

Guru 31670 points

Kim,

Did you do a nand scrub? Is it giving bad blocks error for all the pages? or just a few of them? Is there any difference in behavior after scrub?

0 Hayden Kim over 13 years ago in reply to Renjith Thomas

TI__Genius 15580 points

After uboot, all nand commands are failed.

Also cannot do "nand scrub" because of error.

0 Patrick Chau over 13 years ago in reply to Hayden Kim

Intellectual 280 points

Hi:

Is it the same issue as:

http://e2e.ti.com/support/dsp/davinci_digital_media_processors/f/100/t/118755.aspx

Patrick

0 Renjith Thomas over 13 years ago in reply to Patrick Chau

Guru 31670 points

Kim,

There are timing difference in the NAND. Refer to the AC timing characteristics. This you can try by changing the timing parameters. But I think the timing parameters may not help you directly. I feel that the busy pin has to be used properly. I'm not really sure in your u-boot its implemented properly. I have seen issues before in busy/wait pin support in u-boot.

0 Hayden Kim over 13 years ago in reply to Renjith Thomas

TI__Genius 15580 points

With uboot of latest PSP 3.21.00.04, checked that the "D" nand works ok.

0 Renjith Thomas over 13 years ago in reply to Hayden Kim

Guru 31670 points

Good to know that its working. Did you explore the timings part?

0 Hayden Kim over 13 years ago in reply to Renjith Thomas

TI__Genius 15580 points

With testing using recent uboot, no modification is done.

Thomas, can you inform us where is the code of uboot which implement the "busy / wait" support?

Thank you.

0 Renjith Thomas over 13 years ago in reply to Hayden Kim

Guru 31670 points

I'm not sure about your u-boot code. But most likely it should be there in drivers/mtd/nand_base.c, and another platform specific file inside the same directory.

0 Hayden Kim over 13 years ago in reply to Renjith Thomas

TI__Genius 15580 points

Can you explain the exact point of the busy wait support?

There is too many difference so it is difficult to know the point by file compare.

You may explain the point with the latest uboot of PSP3.21.00.04.

0 Renjith Thomas over 13 years ago in reply to Hayden Kim

Guru 31670 points

Kim,

I haven't gone through the u-boot PSP3.21.00.04. But I can explain in terms of general logic used in u-boot. There is a BUSY/WAIT pin from NAND which is fed to the EMIF/GPMC of the host. Whenever there is any transaction or command issued to the device, the BUSY pin will get toggled till the command is over. You have to read the status of the pin to check whether the command is completed or not.

I have seen in u-boot that instead of using the busy/wait pin they put an arbitrary delay of some duration (eg, ndelay(100);) This will work in most cases where the processing time is less than this. If the device needs more time in processing the command, the delay has to be increased. So you've to increase this delay to get it working in such cases.

The right approach is to use the busy/wait pin which will work always. I'm not sure why this is not implemented properly. I'm not sure whether the same is applicable in your case as well.

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[DM36x] how to support new nand device