NON- VOLATILE SEMICONDUCTOR MEMORY FOR VOLATILEY AND NON-VOLATILEY STORING INFORMATION AND WRITING METHOD THEREOF

A nonvolatile memory has integrated memory cells each operative to carry out writing and reading of information on a random-access basis and each having an electric charge storage structure effective to memorize the information in a nonvolatile state. The information is temporarily written into each memory cell in a volatile state, and thereafter the temporarily written information is written at once into a respective electric charge storage structure of each memory cell, thereby effecting high speed writing of nonvolatile information into the respective memory cells.