Semiconductor storage device

Abstract

Abstract PURPOSE:To easily detect a memory cell which has become a failure, by a user, by providing a switching circuit for outputting one of an output voltage of a step-up circuit and an output voltage of a step-down circuit. CONSTITUTION:The titled device is constituted of a switching circuit 15 of a write/erasion voltage for inputting the VPP outputted from a step-up circuit 8, a write/erasion control circuit 16 for inputting the write/erasion voltage output from said circuit, and a memory cell 17. Also, a register 1 of the s witching circuit 15 stores a data related to what kind of voltage is supplied to the memory cell 17, and when this output is 'H', a holding failure of the data of the memory cell is tested, and at the time of 'L', usual write and erasion are executed. In such a way, by executing a write/erasion test by a lower voltage than a voltage at the time of usual write and erasion, a memory cell in which a holding failure of data has occurred can be detected easily in an early stage by a user side.

Inventors

• 👤 Katsutoshi Yokoyama

Bibliographic Details