Testing
The boundary scan architecture provides a means to test interconnects and clusters of logic, memories etc. without using physical test probes. It adds one or more so called 'test cells' connected to each pin of the device that can selectively override the functionality of that pin. These cells can be programmed via the JTAG scan chain to drive a signal onto a pin and across an individual trace on the board. The cell at the destination of the board trace can then be programmed to read the value at the pin, verifying the board trace properly connects the two pins. If the trace is shorted to another signal or if the trace has been cut, the correct signal value will not show up at the destination pin, and the board will be observed to have a fault.
Read more about this topic: Boundary Scan
Famous quotes containing the word testing:
“Traditional scientific method has always been at the very best 20-20 hindsight. It’s good for seeing where you’ve been. It’s good for testing the truth of what you think you know, but it can’t tell you where you ought to go.”
—Robert M. Pirsig (b. 1928)
“Bourbon’s the only drink. You can take all that champagne stuff and pour it down the English Channel. Well, why wait 80 years before you can drink the stuff? Great vineyards, huge barrels aging forever, poor little old monks running around testing it, just so some woman in Tulsa, Oklahoma can say it tickles her nose.”
—John Michael Hayes (b.1919)
“No testing has overtaken you that is not common to everyone. God is faithful, and he will not let you be tested beyond your strength, but with the testing he will also provide the way out so that you may be able to endure it.”
—Bible: New Testament, 1 Corinthians 10:13.