112VLSI Test Principles and ArchitecturesTABLE 3.1±Basic Boolean Operations for Ternary LogicAND01uORuNOTu00000u10u1u1111u0uuuu1uThe input/output relationships of the three basic Boolean operations using ternarylogic are summarized in Table 3.1. From Table 3.1, one can observe that for anAND operation, the output is determined if one of the inputs is 0. Thus, we saythat 0 is thecontrolling valueof the AND operation. Similarly, 1 is the controllingvalue of an OR operation.Simulation based on ternary logic is pessimistic; it may report that a signal isunknown when in fact its value can be uniquely determined as 0 or 1 [Breuer1972]. To illustrate the information loss caused by ternary logic, the example circuitNis redrawn in Figure 3.5. Let the input vector be
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This note was uploaded on 05/16/2011 for the course ENGINEERIN mp108 taught by Professor Elbarki during the Spring '08 term at Alexandria University.