Ralf Guetlein wrote:
Hello all,
recently I encountered a very strange behaviour of a MSP430F149 during JTAG
use:
When I program the controller via JTAG (and jtag.py), due to some reason,
the controller sticks in a mode which can not be left, not even with a
manual reset (pulling reset pin low). The only way to recover is
interrupting the power supply. This happens in one out of 5-10 cases. My
i have seen lockups too. but very seldom. i cannot say why that is,
neither is it regular enough to find out a reason...
a problem is when your supply goes below 0.4 .. 0.8 V and your device
has no brown out reset circuit. but that would probably mean that you
get a programming error earlier (<2.7V)...
problem is: the device is driven by a rechargeable battery mounted on the
board, and the board is fixed upside down in a can-shaped housing. This
means I have to unscrew the board, unplug the battery, shorten the supply
pins to discharge capacitors, press the reset button (just in case), connect
the battery again, mount the pcb and wait for the next time it happens. Very
uncomfortable...
next time you open it, simply solder a switch in the supply ;-)
Has anyone else seen this problem?
most of the problems with JTAG programming i've seen so far were supply
releated, it was to weak and could not drive enough current.
a second problem can be high load/capacitance on shared jtag pins.
both problems are related to programming problems, not lockups.
chris
