A new array architecture for parallel testing in VLSI memories

Abstract

The authors describe a novel array architecture and its application to a 16-Mb DRAM (dynamic random-access memory) suitable for the line mode test (LMT) with test circuits consisting of a multipurpose register (MPR) and a comparator. The LMT can test all memory cells connected to a word line simultaneously. Testing with random patterns along a word line is easily realized by using the MPR as a pattern register after setting random test data in the MPR. Test time is reduced to approximately 1/1000. Owing to the MPR, the present LMT can achieve flexible testing with high fault coverage. The excess area penalty due to the circuits for the LMT is suppressed within 0.5% in application to the 16-Mb DRAM.<>