Built-In Self-Test Trends in Motorola Microprocessors

The first built-in self-test feature in a Motorola sidered a "wart" until a RAM test application recast it as a "feature." Though the BIST approach-an idea conceived as a way to reduce production costs for the MC6805 family-did not meet its major design objective, the experience provided impetus for the development of BIST techniques for the MC6804P2, which met most of the objectives intended for the MC6805P2. The Motorola microprocessor family has come to incorporate a growing number of testability features; current devices typically employ a combination of BIST and other techniques. If present trends continue, transistor counts for microprocessor-related parts should approach 10 million within 10 years. The authors argue that structured design techniques offer the most promising prospects for solving the design and test problems resulting from this increase in complexity.