DM814x: Warm Reset fails

Thomas Doering

Hi everyone,

We have one very strange issue: When we reboot our DM814x-based custom board via software warm reset it happens on very rare occasions, that the booting fails.

Our normal boot order is: UART, NAND-SPI, NAND. So when the board boots the "CCCC..." are coming at first. After that the device is booted via u-boot from NAND.

In the above mentioned error case, it is not booting at all, meaning even the "CCCC..." are NOT coming. Connecting via JTAG in that state also fails with a "Requested operation failed for security violation" error message in CCS (v6.1.1).

We already checked all power lines and everything seems fine. The only way to recover is power-off / power-on.

Anyone else having this issue or any hints for its reason?

Greetings,
Thomas.

over 9 years ago

0 Thomas Doering over 9 years ago

Intellectual 575 points

For testing we changed the boot order to "NAND => NANDI2C => SPI => UART" and measured the GPMC_OE signal. On normal boot we can see the ROM Boot Code accessing the NAND via GPMC. In the above described error case we cannot see that signal. So somehow the ROM Boot Code is stuck before even "booting".

Can this be some issue with the "CPU Secure Boot Initilization" mentioned in the TRM chapter 4.4.1? The JTAG message "Requested operation failed for security violation" might also point in that direction...

Unfortunately the TRM is not very detailed in that matter.

0 Kaushal Gupta8 over 9 years ago in reply to Thomas Doering

Intellectual 530 points

Hi Thomas,

Plz check the similar threads here: e2e.ti.com/.../285771
e2e.ti.com/.../186829
e2e.ti.com/.../234378

BR
-Kaushal

0 Thomas Doering over 9 years ago in reply to Kaushal Gupta8

Intellectual 575 points

Hi Kaushal,

Thanks for those thread links. Unfortunately none of these threads give a hint on how to resolve our issue.

Regards,
Thomas

0 Prabhakar Lad over 9 years ago in reply to Thomas Doering

Guru 11260 points

Hello,

Can you check if doing a reset during uboot stage has the same issue ('reset' command in uboot) ? can you check if the reset pin is muxed.

Cheers,
--Prabhakar Lad

0 BO over 9 years ago in reply to Prabhakar Lad

TI__Genius 12760 points

Dear Thomas,

let me check and come back asap.

Regards,
Bernd

0 Thomas Doering over 9 years ago in reply to Prabhakar Lad

Intellectual 575 points

Hi,

since the reset command in uboot does a "cold reset" (instead of a "warm reset") it would not be suitable for any analysis concerning this error. In our tests a "cold reset" does not show such a "misbehavior" in general.

So there are two questions now:
1. What's the actual difference between "cold" and "warm" reset?
2. Which of those differences might lead to the described scenario?

Regards,
Thomas

0 Radio-Joe over 9 years ago in reply to Thomas Doering

TI__Mastermind 37500 points

Hello,

Section 2,7 of the Technical Reference Manual, DM8127, DM814x, discusses Resets.www.ti.com/.../sprugz8g.pdf

In cases where you trigger a cold reset (hardware - PORz), warm reset(hardware - RESETZ), or software wamr reset. There are some key differences.

The Reset controller will provide a minimum RESET hold time, to make sure that the desired peripherals are reset. See section 2.7.11 for a discussion of

reset options, and what is reset.

In your warm reset scenario, you might trace the event, or consider triggering a different Warm Reset within the RESET MANAGEMENT.

Some resets trigger a device output GIO pin, you could use this to check that the desired outcome.

Regards,

Joe Quintal

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DM814x: Warm Reset fails