Memory fault diagnosis by syndrome compression

In this paper we present a data compression technique that can be used to speed up the transmission of diagnosis data from the embedded RAM with built-in self-diagnosis (BISD) support. The proposed approach compresses the faulty-cell address and March syndrome to about 28% of the original size under the March-17N diagnostic test algorithm. The key component of the compressor is a novel syndrome-accumulation circuit, which can be realized by a content-addressable memory. Experimental results show that the area overhead is about 0.9% for a 1Mb SRAM with 164 faults. The proposed compression technique reduces the time for diagnostic test, as well as the tester storage capacity requirement.