One of my designs uses the msp430f5341 using the Spi by Wire debugging interface and I'm encountering an odd problem I'm having trouble figuring out. My code is toggling a pin from high to low then back to high. When debugging, CCS5 will stop responding and I will get a "Problem halting cpu" error as soon as I step into the instruction that sets the pin to low.
I suspected that it may have something to do with a pullup resistor (sinking too much current) or noise getting transferred into the SBW lines. I checked the continuity in the circuit and did not notice anything wrong.
When I put a probe (1MOhm|10pF) on the line I am toggling, the debugging interface works fine. Another interesting thing is that when I put a probe on the SBWTCK line while debugging it works as well.
My programming circuit looks just like the one in figure 7 from: http://www.elprotronic.com/files/JTAG-BSL-Pinout.pdf
I've seen no problems with programming or debugging so far, other than this one.
If anyone has any thoughts, I would appreciate some input.