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ricercar
10-07-03, 11:33 PM
The Inquirer points out a "mysterious J5" connector on a X/Pine brand GeForce FX 5600 they review today. Article link (http://www.theinquirer.net/?article=11981). This is the white connector in the upper left.

http://www.theinquirer.net/images/articles/xfx1.jpg

My FX 5900 Ultra engineering sample/reference card has this same "J5" connector, and there are J5 pads on the Gainward 5600 consumer PCB, too.

http://www.theinquirer.net/images/articles/gainly.jpg

WTF? Is this for JTAG testing? Anyone have a clue?

StealthHawk
10-07-03, 11:36 PM
What is JTAG testing :confused:

The Baron
10-07-03, 11:37 PM
note to self: get your ass to college and get an EE degree already

ricercar
10-07-03, 11:47 PM
JTAG is some kind of Boundary-Scan testing from IEEE 1149.14. Please note that I'm already spewing words that I don't really ken.

IIRC there only four JTAG signals (TCK, TMS, TDI, TDO), so I'm not convinced that this J5 is for JTAG.

The Baron
10-07-03, 11:49 PM
Originally posted by ricercar
JTAG is some kind of Boundary-Scan testing from IEEE 1149.14.

Please note that I'm already spewing words that I don't really ken.
Yeah, I knew that from Google, you tool ;)

Descombobulator
10-08-03, 03:58 AM
Originally posted by StealthHawk
What is JTAG testing :confused:

In short, it is a technique/technology for performing in-situ testing of chips. By sending suitable commands on the serial interface, one can check that the interconnectivity on the board is functioning. It can also be used to exercise the test functions built in to the chips themselves.

Manufacturers use this function for fault finding and fault location during card production.

StealthHawk
10-08-03, 05:02 AM
Originally posted by Descombobulator
In short, it is a technique/technology for performing in-situ testing of chips. By sending suitable commands on the serial interface, one can check that the interconnectivity on the board is functioning. It can also be used to exercise the test functions built in to the chips themselves.

Manufacturers use this function for fault finding and fault location during card production.

Soooo, is the J5 connector used for JTAG testing? Or is it unrelated? Or is it possibly related? etc :p

theultimo
10-09-03, 09:27 PM
Hmm...we can hack this connector and do Tests? Maybe program this chip?

Descombobulator
10-10-03, 06:45 PM
Originally posted by theultimo
Hmm...we can hack this connector and do Tests? Maybe program this chip?

Absolutely not! Debugging the JTAG test program usually results in at least a few GPU to doorstop conversions. I don't know if it is a JTAG connector or not, but my advice is to leave well alone.

Unless you're short of a doorstop.:scarey:

(love that smiley.)