Post by thread:[OT] boundary scan and JTAG

05/05/'99 Hello good people, I have some OFF TOPIC questions on JTAG and boundary scan. I have to look into the use of JTAG and boundary scan on a largish production scale for here in Australia, now here comes the crunch-> A large production run to us is in the order of 10000+ (Small in other parts of the world). I actually do question the purpose of such, as the original intonations seem for JTAG seem to be just for connectivity testing, if so then as this and component placement account for somewhere around the 90% of all production errors. These errors can be found with optical inspection. So what are the benefits of such and what is the cost? Then there is the other nice things that JTAG offers, being able to exercise the board, but one can ask the question is this beyond the need for production test, I admit that JTAG device can help test a section that is not JTAG, and create virtual test points. However what is the cost, both in time and equipment? I do understand that JTAG allows the production area to change tests without effectively altering the test jig, and does allow for more tests, and that the introduction costs seem to be small for connectivity testing. But what are the benefits and cost; especially to employ logic function tests? Dennis