Grant Edwards schrieb:
Can anybody confirm that the JTAG applications work when there
are other devices besides the MSP430 in the TJAG chain?
i can't. ;-)
as i understand, even disabled devices in the change add one cycle delay
when shifting data through the registers of the JTAG. so the JTAG code
talking to the MSP430 would need to know that additional delay when reading.
the mspgcc jtag library doesn't do that currently. but maybe you're able
to find out what needs to be changed.
for example on startup. an ID is read out by shifting the 8 bit wide
JTAG instruction register out. which might be a good starting point to
debug as its always the same value.
the MSP403 JTAG allows to source the MCLK from TDI in one certain state
of the JTAG machinery. this probably explains why the MSP430 must be the
first device in the chain. the slau149 application note has some details.
According the the TI datasheets, it's supposed to work as long
as the MSP430 is the first device in the chain (which it is),
but I can't seem to talk to the MSP430.
with msp430-jtag --backend=mspggc, did you try to specify a number of -D
options? it should report quite detailed where it fails.
chris
