Watchdog reset sequence on AM3352

Nomo

Other Parts Discussed in Thread: AM3352

Hello,

I have a question for the watchdog reset sequence on AM3352.
When the watchdog reset is occurred, which reset vector (vector address) is executed?
I put the breakpoint on 0x0000_0000 and 0xFFFF_0000 (ARM reset vector), however the breakpoint doesn't work.

Also, could you teach me what happen after watchdog reset is occurred?
I want to know how AM3352 can recover.

Best Regards.

Nomoto

over 11 years ago

0 Biser Gatchev-XID over 11 years ago

TI__Guru**** 393215 points

Hi Nomoto-san,

The Watchdog reset is an instance of Global Warm Reset. Please see AM335X TRM Rev. J section 8.1.7.4 for details. Table 8-25 shows reset characteristics for different reset sources. After reset the processor always starts up in secure mode. The ROM Code takes care of early initialization. The ROM code switches the device into public mode.

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

Guru 16800 points

Hi Biser-san,

Thank you for your reply.
After reset, is the ROM Code (0x20000) executed at first?

Best Regards.

Nomoto

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

TI__Guru**** 393215 points

Yes, this is correct.

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

Guru 16800 points

Hi Biser-san,

I'm sorry but I have one more question.
Do you know why reset vector isn't located at 0x0000_0000 or 0xFFFF_0000?
0x0000_0000 and 0xFFFF_0000 are used as reset vector for general ARM processor.

Best Regards

Nomoto

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

TI__Guru**** 393215 points

I'm not sure, but I think you will not be able to access the processor before it switches to public mode. Furthermore the public ROM code is not disclosed by TI in any circumstances. Therefore the first moment you can break the processor is at the beginning of MLO execution.

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

Guru 16800 points

Thank you for your reply.
I can understand the public ROM code is not disclosed by TI.

Best Regards

Nomoto

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Watchdog reset sequence on AM3352