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Gru
Level 1
Level 1
5 sign-ins First like given First reply posted

Hello, 

I am working with Aurix TC234 with external watchdog TLF35584. 

I am facing an issue that the PORST pin is not pulled LOW when a Hard reset(service 11 01) is issued.

(see scope attached)

We have another software stream and a hard reset always brings the PORST LOW and back HIGH indicating a power-on reset.

In the new software stream, the hard reset returns a positive response and performs a software reset, but the PORST remains HIGH. We did a code review and nothing has changed with respect to the TLF configuration or PORST. We have added a few start-up tests in the new software. We are seeing other issues, as the PORST is not behaving as expected. 

Are there any constraints for the Hard reset to perform a proper power-on reset?

Thank you,

Gru

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1 Solution
cwunder
Employee
Employee
5 likes given 50 likes received 50 solutions authored

The /PORST pin is not activated by the device when you issue a "software reset".  A power-on-reset can be either warm or cold. With a "warm power-on-reset" the /PORST is pulled low and released while all the power rails remain in their minimal operational range. A "cold power-on-reset" is when the /PORST is activated when one of the power rails is below its operational range.  A "system reset" can be generated by software if the RSTCON.SW=1.

cwunder_0-1697549406780.png

If you have not changed the default behavior of /ESR0 then this pin is activated upon all resets.

 

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5 Replies
Nambi
Moderator
Moderator
Moderator
5 likes given 100 solutions authored 250 replies posted

Hi,

Checking the different program flows of the Software streams would be the best way to resolve this.

Can you check the action performed in either of the software streams when Hard reset(service 11 01) request is received?

At your end, I assume that PORST pin is input of Aurix and output of TLF device. So the TLF device is expected to assert the PORST pin for Hard reset. Is this understanding correct?

Aurix device can only trigger a soft reset using register writes.

You can follow the same procedure of how you are initiating the Hard reset in the software stream where it works as expected.

Best Regards.

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Gru
Level 1
Level 1
5 sign-ins First like given First reply posted

Hi ,

The hard reset from diagnostics (11 01) triggers a reset using 

SCU_SWRSTCON.B.SWRSTREQ = TRUE;
 
In the software, a software requested reset is configured to trigger a system reset(warm power-on reset).
The ROT pin from the TLF is connected to the PORST pin of Aurix.  
 
This HW/SW configuration above is same in both the project streams. 
 
I hope my understanding is correct that I expect the PORST to be pulled low and then high, when a system reset is triggered from software?
 
Thank you. 
 
 
 
 
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cwunder
Employee
Employee
5 likes given 50 likes received 50 solutions authored

"I hope my understanding is correct that I expect the PORST to be pulled low and then high, when a system reset is triggered from software?"

No this is not correct, a software reset from the AURIX does not activate the /PORST pin. If this is needed you need to generate a "Soft Reset" on the TLF35584 to have it pulse the ROT pin assuming this is connected to the /PORST pin.

Gru
Level 1
Level 1
5 sign-ins First like given First reply posted

Hello,

Thank you for your response. As mentioned, we have configured a "system reset" for a software requested reset. As per aurix manual, system reset is a warm power-on reset.

I understand power-on reset is Aurix going from powered->unpowered->powered? 

Which of the power pins on Aurix is pulled low during a system reset, if not the PORST? 

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cwunder
Employee
Employee
5 likes given 50 likes received 50 solutions authored

The /PORST pin is not activated by the device when you issue a "software reset".  A power-on-reset can be either warm or cold. With a "warm power-on-reset" the /PORST is pulled low and released while all the power rails remain in their minimal operational range. A "cold power-on-reset" is when the /PORST is activated when one of the power rails is below its operational range.  A "system reset" can be generated by software if the RSTCON.SW=1.

cwunder_0-1697549406780.png

If you have not changed the default behavior of /ESR0 then this pin is activated upon all resets.