Semiconductor device

摘要

A semiconductor device for comprising electrically alterable read-only memories formed in and on the same silicon substrate is disclosed. The read-only memories are driven by both a first voltage having one polarity and a second voltage having the opposite polarity. The first voltage is supplied from an external unipolar voltage source, but the second voltage is generated by a bipolar voltage generator which is located on the same silicon substrate and is driven by said external unipolar voltage source.