Grant Edwards wrote:
...
It never has any problem entering JTAG mode. The problem is
that after the program operation completes, there are almost
always a few bits that didn't get programmed -- they're 1's
when they should be 0's.
I can run msp430-jtag --upload all day long and it'll work
every time. Same with a program operation, the program
operation itself always succeeds.
The problem is that the verify fails: a couple bits (random
locations as far as I can tell) just don't get programmed from
1->0.
I've tried varying Vdd from 2.5 up to 5V -- no difference.
From an outsider's viewpoint, without any understanding of the details
of the interface, that sounds like a timing problem - everything starts
as a 1 and if you don't give a Flash Write enough time, it stays 1. Are
there some write-frequency dependencies in the JTAG code?