Summary: This paper proposes a new test mode circuit which enables the massively parallel test of DRAMs with a standard LSI tester with little chip area penalty. It is useful to enhance the test throughput that can't be improved by the conventional multi-bit test mode. And a new redundancy circuit that detects and repairs the short circuit failures in the memory cell array is also proposed. It greatly improves the yield of super low power 256 Mbit DRAMs.