<sys64738>
yeah i have an spc56xx here for some reason (free s amples is the reason)
<jn>
NXP application note AN3283 was my starting point, it's a very nice documented and looks quite implementable, but unfortunately it's not the debug protocol that my chips speak
<jn>
(OnCE vs. COP)
<sys64738>
don't they speak Nexus? (cf AN4088) or is it different on the 83xx?
<jn>
OnCE is mentioned together with Nexus (maybe the same, maybe a different one, not sure), but on the 83xx and a few others i only see JTAG/COP in the documentation
<clever>
jn: the main points i learned from #openocd, is that the capture-{ir,dr} stage, will load the selected ir/dr into the shift register, and the update-{ir,dr} will write the shift reg back into the ir/dr, and trigger the hw to begin reacting to it
<clever>
and for arm debug specifically, the debug is built around that shift register, you write a 35bit command+data, and get a result for the previous command out of the shift register in the saem action
<clever>
if the result says WAIT, then the command isnt done yet, and it ignored the command you just sent, so you should retry
<clever>
and a smart probe can then just repeat the ignored command, until it isnt ignored
<jn>
sys64738: AN4088 mentions MPC55xx/56xx, which is also what AN3283, and the JTAG/COP protocol looks *very* different from what i've seen so far
<sys64738>
ah
<jn>
* what AN3283 is about
<jn>
i've been calling it OnCE instead of Nexus since my initial research, but documentation is so sparse that i might just be wrong in my naming