AM623: primary/backup boot pins for OSPI/SPI

HS FAE Germany

Part Number: AM623

Hi,
is the constellation OSPI for primary boot and SPI for backup boot possible? In backup mode there is no boot configuration possible for SPI or does it use bit 7+8 for mode and Csel? If yes, then there is no individual configuration for OSPI primary and SPI backup boot mode pins possible and boot use the same CS.

Regards, Holger

over 2 years ago

0 HS FAE Germany over 2 years ago

TI__Mastermind 32250 points

can anybody answer my question?

0 Andreas Dannenberg over 2 years ago in reply to HS FAE Germany

TI__Guru 69707 points

Please allow until early next week for a response, thanks.

0 Andreas Dannenberg over 2 years ago in reply to Andreas Dannenberg

TI__Guru 69707 points

I just discussed with the ROM team, they confirmed what I thought that for SPI as backup boot mode on AM62x and AM64x that MODE=CSEL=0 is implied. Will file an enhancement request against TRM to have this clarified.

As for your specific scenario of...

1. Primary boot: OSPI
2. Backup boot: SPI

...this should in theory be possible if you use CSEL=1 for OSPI, so this way it won't conflict with CSEL=0 implied for SPI backup boot, which you need to connect for that device.

However since the same OSPI0_D0 / OSPI0_D1 / OSPI0_CLK signals would be used for both chips I think this poses challenges to make a proper electrical design considering signal integrity, as especially OSPI in high-speed mode will impose unique challenges here. Let me re-assign this to an expert from the HW team to comment further.

Regards, Andreas

0 peaves over 2 years ago in reply to Andreas Dannenberg

TI__Guru 63145 points

We do not support attaching multiple devices to the OSPI port.

Regards,
Paul

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AM623: primary/backup boot pins for OSPI/SPI