What is JTAG and where is it used and how to program it???

[amnandu]

Hello friends,


What actually is JTAG?? what does it do??Where do we use it?? How to program it?? any good tutorials to learn from the scratch???

Thanks

 

[bassa]

Start from here
Joint Test Action Group - Wikipedia, the free encyclopedia

 

[amnandu]

Thanks for the link but i really want to know how???

Let us suppose i have a PCB with a Xilinx chip on it... how am i going to write a code for it to check for the boundary scan?? and what all does this scan??

 

[bassa]

1. Read datasheet of particular Xilinx chip.
2. Connect TDI, TDO, TCK and TMS pins to your programmer.
3. Load Xilinx iMPACT
4. Perform Boundary Scan

read more about

 

[haykp]

JTAG is a mechanize which allows o test the chip/PCB for faults. You can imagine JTAG as a state machine which can load data in PCB and get the data out from that PCB.