The LT1280 for Through-the-Pins Testing of the Thermal Conduction Module

Testing the thermal conduction module (TCM), the high-density field-replaceable unit (FRU) used in the IBM 3081 processor models, and diagnosing the faults encountered to a minimal repairable set of entities posed a new problem for the IBM engineers. The requirement and the economic necessity of thoroughly exercising the entire TCM logic and random access memory (RAM) array structure through the input/output pins of the TCM are discussed. This is followed by a description of the test system alternatives and the LT1280 [logic tester having 1280 input/output (I/O) pins] as the selected TCM manufacturing test system. The TCM logic density and high I/O count required new concepts of test system organization, size, and complexity to achieve a test and diagnostic system with high flexibility and high throughput capability.