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JTAG : quick'n'dirty style

Posted: Thu Apr 12, 2012 8:36 pm
by beatfreak
Hi,

for all those who are some kind of inhibited regarding JTAGging their Flashs...

I made some successful attempts with JTAG on some bintec Routers with the following Setup

Ubuntu 8.04 hardy (better 10.04 or newer)

urjtag (available in ubuntu repositories since lucid)

old PC with parallel Port (in BIOS set to ECP / EPP or both) (in my case 75MHz 40MB RAM, needs 28 hours for 8MB Flash to read, more power strongly recommended ;D )

and a short <= 20cm jtag cable consisting of 1 db25 male connector, 4 (5) 100 Ohm Resistors (330 Ohm will work also) and a connector for the headers on pcb, wiring like Xilinx DLC5 Parallel Cable III unbuffered

then you only need to find the 5 pins TDI, TDO, TMS, TCK and GND. Data pins are usually 3,6V against GND