What does the term "JTAG" stand for ?

Question

I keep seeing this term in the computer magazine "Circuit Cellar" and I never can seem to find the answer!

Answer 1

http://en.wikipedia.org/wiki/JTAG

It refers to a system incorporated into larger microcircuits of all kinds, whereby engineers/designers can test pins (sometimes 1100 plus pins) on an integrated circuit -- for functionality and connections to the printed circuit board -- and if 2 JTAG chips are on-board, then the engineer can check from IC to IC as well.

JTAG ports can also serve as serial ports for programming some kinds of FPGAs (programmable logic).

To me, JTAG is a godsend.

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Answer 2

Joint Test Action Group
JTAG as used when related to electronics (particularly hacking Digital Satellite terminals and wireless routers) is an serialized interface used to making programing changes to a device on the fly after assembly. Basically its a hard wired connection that is used to flash new data into memory circuits inside a device, or access chips in it to get information out of it.

Answer 3

"Joint Test Action Group (JTAG) is the usual name used for the IEEE 1149.1 standard entitled Standard Test Access Port and Boundary-Scan Architecture for test access ports used for testing printed circuit boards using boundary scan."

See this Wikipedia article for more details: http://en.wikipedia.org/wiki/Jtag