READDONLY MEMORY WRITE UNIT

摘要

PURPOSE:To reduce write errors by providing CPU with the function of counting and deciding on information written in ROM. CONSTITUTION:This unit consists of an I/O control which reads information to be stored, RAM stored with information, CPU with a counting decision circuit equipped with the function which counts the number of bits of each ligical value by reading information from RAM, decides on a logical value with more bits, and makes this logical value correspond to that stored previously in the memory before write operation, and a driver circuit which writes needed information in the memory according to the coordinate. Consequently, write errors of ROM can be minimized.