David, I have had similar experience with a couple of msp430f149 targets. Like you, I've had to unsolder and replace a couple of parts that even CSPY would not talk to. I know in one case that I had inadvertently written code that disabled the system clock shortly after startup, and I could not get in with the JTAG interface, until I started mucking about with a test lead connected to the reset line. It seemed that the noise introduced while I was doing this somehow let the JTAG interface get control so that I could program new code. Interestingly however, when I put the same bad code in a socketed part installed in a TI msp-ts430pm64 evaluation board, I had no difficulty using the JTAG interface. I sure wish that I knew why.
If you continue to have these problems, you might want to have your code enter a tight loop on startup when an otherwise unused input is held in a particular state (say 0). Tie the input hi for normal operation, and if your target starts misbehaving again, force the input low and see if that helps. Walt Spicker ----- Original Message ----- From: "David Brown" <[email protected]> To: <[email protected]> Sent: Monday, January 06, 2003 12:21 PM Subject: [Mspgcc-users] Problems with jtag - could not find device > Has anyone else had problems with an msp430 that works fine for a while, and > then suddenly will not respond to the jtag interface any more? This has > happened to me on a number of occasions - the processor works fine, then > suddenly all I get from rproxy is "Could not find device", and from pyjtag > "Could not reset target (no connection?)". The jtag interface works > perfectly on another card (I've got two cards working together), and I've > also tried C-Spy on the now-broken processor without any luck. On previous > occasions the only thing I have been able to do is replace the processor if > I need to reprogram it (the processor runs fine - it is just the jtag > interface that doesn't work). If anyone has any clues as to why this might > happen, or what can be done about it, I'd be very grateful to hear them. > > mvh. > > David Brown > Norway > > > > > > ------------------------------------------------------- > This sf.net email is sponsored by:ThinkGeek > Welcome to geek heaven. > http://thinkgeek.com/sf > _______________________________________________ > Mspgcc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/mspgcc-users >
