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psoc1 hanging | Cypress Semiconductor

psoc1 hanging

Summary: 3 Replies, Latest post by danaaknight on 22 Aug 2012 06:01 AM PDT
Verified Answers: 0
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Gee's picture
9 posts

I am using the cy8c20546-24pvxi for touch sensing on my keyboard. even after implementing a Watchdog my psoc is hanging at unpredictable times. Kindly leme know asap what the issue can be. Is thr any possibility that the watchdog timer also hangs if the internal ILO/IMO hangs? It is urgent. Expecting a reply asap.


Arvind Krishnan's picture
Cypress Employee
143 posts



I'm not sure how the ILO/IMO can "hang". Perhaps you can elaborate on the problem or if possible attach the project.

It will help us understand the issue better.





user_14586677's picture
7646 posts

Unexpected behaviour can come from a number of sources -


1) Code based.

2) Transient voltages outside specification limits.

3) External clock hiccups.

4) System noise.


Tracking down -


1) For code based errors, disable specific modules of code, one at a time, and see if problem

disappears. Plant a heartbeat monitor in sections of code, a pulsing led, and look for any module

that stays active after the hang, knowing whats running can also be a clue.


2) Set a scope up, DC trigger, and look for pin violations interfaced to externals. Same with

Vdd. If you get a trigger, say set for 6V on Vdd, or - 1 V on a pin, find the source and cure.


3) Using a scope, if external clock, set scope trigger for runt pulse detection. Also use scope

on xtal pins (FET probe) and look for voltage violations as discussed earlier.


4) Use a scope on infinite persistence and look at external pins, Vdd, Vss, for excessive



Just some suggestions, regards, Dana.

user_14586677's picture
7646 posts

Of course a keyboard is a classic static problem environment.


Scope again set to trigger on V or T violations a big help. Note scopes can also be triggered

on pattern violations for multi channel scopes.


Regards, Dana.

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