CIRCUIT FOR IMPROVING TEST COVERAGE AND SEMICONDUCTOR MEMORY DEVICE HAVING IMPROVED TEST COVERAGE

PURPOSE: A circuit for improving test coverage and a semiconductor memory device having an improved test coverage are provide to improve a data coverage by testing a connection of a logic circuit. CONSTITUTION: A first data input buffer(32) is connected to a test pad and outputs a write signal in a test mode. A data input multiplexer(33) is connected to a first data input buffer. When the inputted test enable signal has a first logic level, a data input multiplexer is started to output the record signal. A second data input buffer is connected to the bump pad and the data input multiplexer. If test enable signal is the second logic level, the second data input buffer is started to output a readout signal which is read out by the memory cell array. A comparator(38) is connected the first data input buffer to expand the data coverage.