Write-in voltage source incorporated in electrically erasable programmable read only memory device with redundant memory cell array

Abstract

A write-in voltage source is incorporated in an electrically erasable read only memory device for supplying a write-in voltage level to memory circuits of a redundant unit as well as a data storage, and comprises a first control circuit responsive to a first instruction signal indicative of a power voltage level or a write-in voltage level and producing first and second control signals complementary to each other, a second control circuit responsive to a second instruction signal indicative of a ground voltage level and producing third and fourth control signals complementary to each other, a first level-shifting circuit responsive to the first to third control signals and producing one of the write-in voltage level, the power voltage level and the ground voltage level, and a second level-shifting circuit responsive to the first, second, and fourth control signals and producing one of the write-in voltage level, the power voltage level and the ground voltage level so that the first and second level-shifting circuits independently supply the designated voltage levels to the memory circuits and the data storage.

Dependencies are inferred from the claim text.