AM335x Fast External Booting

Prad1

Other Parts Discussed in Thread: AM3352

Hi,

We are trying to boot AM3352 using NOR flash(Non-muxed) in "Fast External Booting" mode SYSBOOT[4:0]=11111b .
The TRM manual says "in this mode the device is connected in XIP_MUX1 configuration",
but in our case the ROM Code seems like trying to access the "XIP_MUX2" pins.

During the boot process we see changes in the LCD_DATAx pins(Pin used for XIP_MUX2 mode)
instead of changes in GPMC_Ax pins as in XIP_MUX1 mode.
Please let me know is there is any settings to be considered with Fast External Booting.

Best Regards
Prad

over 11 years ago

0 Biser Gatchev-XID over 11 years ago

TI__Guru**** 393215 points

Hi Prad,

Can you give all SYSBOOT[15:0] pin settings?

0 Prad1 over 11 years ago in reply to Biser Gatchev-XID

Genius 3825 points

Hi Biser,

Thank you. I need to check with the customer, I will come back with the details.

0 Prad1 over 11 years ago in reply to Prad1

Genius 3825 points

Hi Biser,

Below is the SYSBOOT[15:0] pin setting.
0100 0001 0101 1111

It works properly if we change the Boot Sequence to "XIP_MUX1"
with SYSBOOT[4:0] :10000b.
But it doesn't work properly in case of "Fast External Boot" settings.

Regards.
Prad

0 Biser Gatchev-XID over 11 years ago in reply to Prad1

TI__Guru**** 393215 points

Hi Prad,

This sounds strange indeed. I will ask the factory team to check if there isn't an error in the TRM. Is there any special reason the customer wants exactly fast external boot?

0 Prad1 over 11 years ago in reply to Biser Gatchev-XID

Genius 3825 points

Hi Biser,

Thank you.
I believe there is no special reason but our customer wants this
board to support bith USB and Fast Eternal boot.

Regards.
Prad

0 Prad1 over 11 years ago in reply to Prad1

Genius 3825 points

Please let me know if there are any updates or suggestions on this topic.

0 Biser Gatchev-XID over 11 years ago in reply to Prad1

TI__Guru**** 393215 points

This has been escalated internally. The factory team are investigating, but it may take some time.

0 Biser Gatchev-XID over 11 years ago in reply to Biser Gatchev-XID

TI__Guru**** 393215 points

Hi Prad,

The factory team have confirmed that this is an error in the AM335X TRM. Section 26.1.6.1 should be corrected to read:

"Addr/Data muxed device or a non-muxed (selected using SYSBOOT[11:10]) device in connected in XIP_MUX2 configuration"

This will be corrected in the next revision of the TRM.

0 Prad1 over 11 years ago in reply to Biser Gatchev-XID

Genius 3825 points

Thank you so much for the confirmation.I shall inform this to our customer.

0 Chris Kessell over 11 years ago in reply to Biser Gatchev-XID

Intellectual 260 points

Hi,

If I'm reading the TRM's description of the XIP_MUX2 pin usage correctly, the GPMC_CSN2 pin is active during fast external boot. If so then the CSN2 pin must be avoided as a chip select output since it would lead to bus contention during the boot process.

Could you clarify if that interpretation is correct?

Thanks.

0 Biser Gatchev-XID over 11 years ago in reply to Chris Kessell

TI__Guru**** 393215 points

Yes, this is correct.

Processors

Processors forum

AM335x Fast External Booting