Home made JTAG interface

As part of getting the Jtag-Arm9 program going I had to create a simple JTAG interface. This interface is just a simple buffer between the PC's parallel port and the JTAG pins on the processor.

Modeled around the same pin out as the Macriagor Wiggler (to enable the use of either with Jtag-Arm9), it is extremely simple. The circuit diagram can be found here (png or txt ).

Building the board is a simple proceedure, I have use SMD devices as they were available through work and size wise they work quite nicely. There is no reason why you can't use a large through hole devices, in fact it doesn't even have to be a '244

The unused pins of the '244 where removed to allow the device to be soldered down to 0.1" veroboard without them shorting out. The device is also fitted at a slight angle to allow 'tracked out'.

Bare Board

picture of bare circuit board


picture of front of board


picture of reverse of board

Hope you guys have fun....
Simon Wood. (c) July 2001