MSP430F5324: JTAG Programmer Issue

Hey Laura,

I'm trying to understand what has changed.  Is it s new programmer, or has something on the board changed.  Have you used this exact programmer on your previous boards?  

Thanks,

JD

Yes, this same programmer is used in existing production testers and thousands of devices have been built. This issue has not been previously reported.

The troubleshooting that I did used the same programmer to capture the “good board/bad board” images from the new design. I’ve also captured the programming sequence of the old design using the same programmer and it looks identical to the “good board” captures.

There were no component changes related to the MSP430 circuitry or JTAG. The changes related to this new design involve a 4G modem on the board which is not powered up during this programming.

Hello Laura,

So, the programmer and the programming circuitry is the same?  

If that's all the same, my best guess is the issue then is related to the power rail.  What does the power rail look like?  Is there noise or drooping?    Is it supplied from the programmer or externally?     

Thanks,

JD

I see no noise or droop. I have powered the device both from 3.3V supplied by the PCBA and the power supplied by the Programmer. I’ve tried adding additional bypass (bulk and HF filtering).  When powering from the Programmer I tried a range of Vcc voltages from 2.5V to 3.4V (programmable through the command line) but none of these things worked on a bad board.

I also found that the MSP430 will actually program OK on a good board without any internal or external power, apparently power bleeding through the JTAG pins provides enough power back to Vcc to program the device (I think I was seeing about 1.5V). So while I agree that the power is a logical place to look I did not see anything of concern on a bad board and a good board programs OK over a wide range of voltages.

Hey Laura,

It's not clear to me what the issue is.  I'm going to quickly summarize my understanding:

• Failure is being seen on 25% of new boards.  
• Using the same MSP-FET on both previous boards and new boards.  
• The Programming circuit is identical on both boards.  Continuity has been checked.    
• The JTAG interface has been scoped and starts identical on good and bad boards, but eventually fails on bad boards. 
• Different power configurations have been tested and additional filtering applied.

The boards that fail programming, do they always fail?

Maybe the devices have been damaged somehow? 

On this new design, The next test might be to light the chips off the "Bad" boards, and move them to a "working" board.  That way we can see if the issue follows the device or the board.   Is this possible?  

Thanks

JD

Your summary is correct.

If a board fails it always fails.

We have done some chip swapping and found that the problem followed the board and not the chip. I’m going to try to do some more parts swapping just to make sure that conclusion is correct. I may try to wire directly to a chip and program and if that works incrementally tie pins back to the board to see what causes the failure. I will keep you posted.

Are there any other programming software packages or programmers that support the MSP430F5324?

Hey Laura,

Very interesting issue.  Maybe also check the capacitance of the lines and see if there is anything different?  I assume if it was enough to cause communication failures, you would see it when you captured the communication. 

As for programmers, MSP-FET is the latest programmer released by TI and is the best to use here.  There are some other options, such as the MSP-GANG, mainly for production programming.  Then there are a couple 3rd party vendors out there. 

Let me know if your testing turns anything else up. 

Thanks,

JD