OMAP L137 : SPI Boot Mode with SPI ATMEL Flash AT45DB642

Vincent Latapie

According SPRAB04F document :

"SPI Flash: The SPI flash device must use 24-bit addressing, and its read command must equal 0x03.
The bootloader will look for an AIS image at offset 0x00000000."

The probem is that the standard read command 0x03 for AT45DB642 ATMEL Flash does not seem to be really standard...

My Flash Page Size is 1056 bytes and when I try with one standard read command (0x03) to read more than 1056 bytes, all returned bytes beyond 1056 are dummies (and not the content of next page..)

I have made SPI_read_bytes adaptation for both UBLs (DSP and ARM) and also for UARTFlashWriter tools (so after bytes checking I know my Flash is correctly programmed)...

But I cannot modified internal ROM Bootloader which uses standard read function (with or without sequential read option) in SPI boot mode

Doest it mean than ATMEL FLash is not supported for SPI Boot Mode????

Thanks in advance

regards

over 13 years ago

0 Rahul Prabhu over 13 years ago

TI__Guru** 116170 points

Vincent,

A similar problem was posted on the forums and seem to be resolved . Look at the following thread for clues to resolve this issue:

http://e2e.ti.com/support/dsp/omap_applications_processors/f/42/t/113074.aspx?pi24527=2

Hope this helps.

Regards,

Rahul

0 Vincent Latapie over 13 years ago in reply to Rahul Prabhu

Intellectual 265 points

Rahul,

first thank you for your answer and thank you for the link

I read the post and indeed problem seems to be besolved for AT45DB321 which allows page size configuration.

It is not the case of the AT45DB642 whose page size by default is 1056 (1024+32) (and not configurable)

According to the post, page size alignment seems to be important so I don't know what to think of this 1056 bytes

Furthermore, I suspect that ROM coded SPI Bootloader of OMA L137 uses low frequency read command (OpCode 0x03) to download DSP UBL from SPI FLash

Unfortunately, this standard command does not have expected behaviour for AT45DB642 (I'm in contact with ATMEL for this) because after 1056 the bytes returned are dummies meaning that you cannot read more than 1056 at once

Any information concerning implementation of ROM coded bootloader would be appreciable

Thx

0 Rahul Prabhu over 13 years ago in reply to Vincent Latapie

TI__Guru** 116170 points

Vincent,

All the constraints and boot configurations on SPI boot are documented in the Bootloader App Notes. SPI boot reads are configured at 923Khz.

Refer to section 6 and 9 of the bootloader App Notes and let me know if you need some more information on ROM bootloader.

http://www.ti.com/lit/an/sprab04g/sprab04g.pdf

Regards,

Rahul

0 Vincent Latapie over 13 years ago in reply to Rahul Prabhu

Intellectual 265 points

Rahul,

thanks a lot however the link seems to be broken :(

regards

Vincent

0 Rahul Prabhu over 13 years ago in reply to Vincent Latapie

TI__Guru** 116170 points

Vincent,

I have corrected the link in my earlier post.

Regards,

Rahul

0 Vincent Latapie over 13 years ago in reply to Rahul Prabhu

Intellectual 265 points

Rahul,

Thanks for the update, I knew this document but I missed information of section9 and especially this precision :

"SPI Flash: The SPI flash device must use 24-bit addressing, and its read command must equal 0x03.

The bootloader will look for an AIS image at offset 0x00000000."

And unfortunately, AT45DB642 does not support 0x03 low frequency read command meaning this flash is not compliant with OMAP L137 boot process.

Thank you very much for your effective support

regards

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OMAP L137 : SPI Boot Mode with SPI ATMEL Flash AT45DB642