And secondly . . in the boundary scan when do you say that the test has failed..please provide some examples...
Boundary scan and chip testing or PCB-testing (with a bed of nails) is nothing special to PSoC. Better ask Mrs. google for more infos or find something in wikipedia.
A tutorial -
Bed of Nails refers to a grid array of spring loaded pins, where pins are
loaded into specific geometrical coordinates corresponding to test pads
on a PCB. The PCB has alignment holes, usually at corners, to facilitate
accurate registration of the pins. Thats how a tester gains connection to a
PCB. Then a test program issues various stimulus, V & I, and measurements
are made. Think of a system level test.
Boundary scan plays a role both in chip testing and board level testing, the tutorial
will cover that.
Teradyne key supplier in test equipment. Maybe they have some training videos
that will give you an overview.