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Blackcat unable to communicate with BCM6358

pedro

Member
I have been doing tests and more tests with Blackcat , and it looks that it is not compatible with Broadcom 6358 chipset over a jtag port .
I am just posting in case anone else had success with this Chipset in blackcat then could reply here , and at same time i am posting for Blackcat software programmers maybe in future implement this processor on blackcat compatible device .
Anyway , i just ordered another jtag programmer FTDI to try with openocd in linux and make sure that it is compatible or not .
I am leaving some pictures i just took , one from the program and another from blackcat connected .

image.jpg


Dscf1883.jpg


In case anyone here had success with blackcat on this CPU , then leave a reply .
 
Well the JTAG engine should work with ALL JTAG ports. It may or not support the Flash memory, but JTAG is universal. So my only though is that the JTAG port you are using is either damaged, or not wired correctly.
 
No , it is not that .
I read on zjtag sourceforge that some cpus need ntrst activated to enable jtag port , and in my case i did not had ntrst connected because the manufacturer removed one resistor from the board .
 
it dont work that way , if i bridge that resistor what will happen is that that pole will be connected directly to the GND .
If you look into the picture , and if i am not mistaken right now , is single pole on one of the rows (Down) , if you look correctly , you will see on the PCB (R35) , and that R35 connects ntrst to the GND .
So what happens is if i bridge it , then when blackcat sends an positive signal thru that pin it will be discharged on the on that bridge before it gets to the CPU (some sort of short circuit) .
so , a resistor is put there to avoid that .
My doubt is what type of resistor should be (value) , a very low resistor will be almost the same thing as a short circuit , but an higher value it could not send enough GND power to the CPU .
i read on other models that they use a 100ohm resistor , but i am not sure about that on this router model .
And to complicate even more , these new routers uses SMD technology , witch it turns more difficult the soldering and even putting a normal resistor there due the lack of space .
 
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