MSP430 Reset pin Issue

Ayush Jain1

Other Parts Discussed in Thread: MSP430G2553, LM8365

Hello guyz,

One of our pcb with msp430g2553 controller was put on test. During testing, the board suddenly stopped working. On detailed analysis it was found that controller was getting proper 3.3V voltage. The reset pin had strange waveform on it, which can be seen in the image attached. Following is some additional information:-

1. We had tested this board for 2 days but suddenly problem surfaced.

2. The firmware and similar boards have tested several times and there have never been any problem.

3. RST pin is pulled up with 47 k ohm and 1nF.

4. When we applied 3.3 V direcly to RST pin, the board became function. [It means that program in flash was intact]

5. Then I tried reprogramming the board and strangely the problem got resolved and board is functional now.

Guyz need your suggestions to identify and solve this strange issue.

Thanks.

over 9 years ago

0 Charles Oladimeji over 9 years ago

TI__Mastermind 33805 points

Hello,

This is the first of such problem.

When you remove direct 3.3V connection does the waveform show up on the reset pin again?
Also can you send a snapshot of that part of the schematic diagram showing what else is connected to the reset pin?

Thanks,
Charles

0 Ayush Jain1 over 9 years ago in reply to Charles Oladimeji

Prodigy 250 points

Dear Charles,

Thanks for the reply, No, after programming waveform was normal.Please find attached schematic.

When problem occurred we even tried removing SVS but problem still persisted.

0 Charles Oladimeji over 9 years ago in reply to Ayush Jain1

TI__Mastermind 33805 points

Hi,

I don't see anything that stands out here at first glance.
you might be experiencing some kind of reset. Best guess right now is the watchdog timer reset.

I will check in the lab what this reset looks like on the reset pin and get back to you

Thanks,
Charles

0 Ayush Jain1 over 9 years ago in reply to Charles Oladimeji

Prodigy 250 points

Dear Charles,

I will be waiting for your reply.

Thanks.

0 Brian Boorman over 9 years ago in reply to Ayush Jain1

Guru 25210 points

The 47K/1nF RC combination is recommended for the RST input pin on the MSP430. However, you are driving this pin with the supervisor chip as well. Could the problem actually be with the LM8365 chip?

0 Ayush Jain1 over 9 years ago in reply to Brian Boorman

Prodigy 250 points

Dear Brian,

Thanks for the reply. Even after removing LM8365, the problem persisted & it got solved after programming. So problem doesn't seem to be with supervisory IC.

Thanks.

0 Charles Oladimeji over 9 years ago in reply to Ayush Jain1

TI__Mastermind 33805 points

Hello,

Sorry for the long wait. I have not been able to recreate this waveform on the reset pin using the Launchpad. However, I expect that if its a software issue then all other things been equal it should happen again.
After testing the board for another ~2day period, did the same problem occur again?
Are you experiencing any other issue with that particular board?

You might still want to check to make sure the watchdog is disabled just to be sure.

Regards,
Charles

0 Ayush Jain1 over 9 years ago in reply to Charles Oladimeji

Prodigy 250 points

Hi Charles,

Thanks for the reply.

The problem occurred in a particular board out of 20 boards so It seems to be hardware problem.

Watchdog timer is disabled and there is no other issue with the board.

I will again put board on testing and let you know the results in 3-4 days.

0 Charles Oladimeji over 9 years ago in reply to Ayush Jain1

TI__Mastermind 33805 points

Hi,

DId this problem happen again after the rerun?

Regards,
Charles O

0 Ayush Jain1 over 9 years ago in reply to Charles Oladimeji

Prodigy 250 points

Dear Charles,

Problem did not occur again. Letz wait for few more days.

Thanks.

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MSP430 Reset pin Issue