Abstract: An arrangement that will provide multiple communication paths for the simultaneously testing of a plurality of un-diced chips on a semiconductor wafer that will simultaneously permit each such communication path to service more than one chip while using a minimum number of tester contacts. These and other objects, features and advantages of the present invention are accomplished in a semiconductor wafer having thereon a number of kerf isolated integrated chips, each of said chips being coupled to at least two different ones of strategically placed administration circuits via two different stimulus buses; each chip being coupled to each administration circuit via selection control circuits laid down in the kerf area between the chips. It is this redundancy that significantly reduces the possibility of failure associated administration or selection control circuits.

Abstract: An arrangement that will provide multiple communication paths for the simultaneously testing of a plurality of un-diced chips on a semiconductor wafer that will simultaneously permit each such communication path to service more than one chip while using a minimum number of tester contacts. These and other objects, features and advantages of the present invention are accomplished in a semiconductor wafer having thereon a number of kerf isolated integrated chips, each of said chips being coupled to at least two different ones of strategically placed administration circuits via two different stimulus buses; each chip being coupled to each administration circuit via selection control circuits laid down in the kerf area between the chips. It is this redundancy that significantly reduces the possibility of failure associated administration or selection control circuits.

Abstract: A method an apparatus for testing logic circuits containing a set of scan chains, each set of scan chains comprising a multiplicity of scan chains. The apparatus comprising: a scan input; a scan output; an input shift register coupled between the scan input and the set of scan chains, each first stage of different scan chains of the set of scan chains coupled to a different stage of the input shift register; and an output shift register coupled between the scan output and the set of scan chains, each last stage of different scan chains coupled to a different stage of the output shift register.

Abstract: In a level sensitive scan design (LSSD) circuit embodiment for testing the behavior of logic circuits, a mechanism is provided for generating a skewed load of data into a set of shift register scan string latches. The nature of the input scan string assures that a certain number of 0 to 1 or 1 to 0 transitions occurs as an input to the block of logic being tested. Furthermore, a mechanism for delaying by one system clock cycle time the capture of information from the logic block in a second shift register scan string provides a mechanism for testing for the occurrence of short paths and long paths while preserving testability for stuck-at faults. Furthermore, all of these advantages are achieved without impacting the traditional stuck-fault test capabilities of the level sensitive scan design methodology.

Abstract: A hybrid random pattern self-test approach is employed in an on-chip fashion to provide desired test signals to circuits on the chip. A simplified weighting circuit is shown to be effective even when only a single bit from a linear feedback shift register is employed for random signal generation. The reduction in linear feedback shift register size and associated weighting circuitry enables the apparatus to be much more readily usable in an on-product configuration thus resulting in significant initial and subsequent test circuit advantages.

Abstract: A memory embedded in a integrated processor chip is dynamically stressed tested by repeatedly writing a test pattern to the data locations of the memory in which a high percentage of the memory cells are sequentially written with complementary data in order to create a high stress on the memory devices. The test pattern is generated as a function of the number of address locations of the memory and the number of data bits of a memory data word. The test pattern is rotated each time the memory is addressed. The test pattern preferably has a contiguous group of digits with the number of digits in the contiguous group being a function of the number of address locations and the number of data bits in the memory word. The memory data input register is configured as a recirculating loop and additional dummy bits are added to provide recirculating loops longer than the data input register.