A Modified Test Pattern Generation Architecture for Fault Detection in BIST

Abstract

Multiple test patterns varying in a single bit position is generated for built-in-self-test (BIST). The test patterns generated using Johnson Counter and Seed Vector lacks in fault coverage. So Seed vector block is eliminated and patterns varying in single bit position is generated using 8 bit Johnson Counter has been proposed to have the required fault coverage with reduced test length. The generated test patterns have an advantage of minimum transition sequence. The methodology for producing the test vectors for BIST is coded using VHDL and simulations were performed with ModelSim 10.0b. The Area utilization and the power report were manipulated with the help of Xilinx ISE 9.1 software. The area reduction of 58% and power reduction of 9% is achieved while generating test patterns using Johnson counter.