| 摘要 |
<p>PURPOSE:To attain easily the partial rewrite of a memory cell array in a short time by providing a spare decoder using a nonvolatile semiconductor memory element having the capacity for write of address data and a spare memory cell to a part of the memory cell array. CONSTITUTION:In rewriting the storage content of the memory cell of a row line R0, the input of address data A0-Ai is set to 0, the input of A'0-A'i is set to a high voltage, the input of R/P'i is set to 0 and the input of R'/P1 is set to a high voltage and a program pulse of high voltage is impressed to a power supply terminal 16, then the address of A0-Ai=0 is assigned to the row line R'i, and in bringing the state to the read state by setting as A0-Ai=0, A'0-A'i=1, R/P'1=1 and R'/P1=0, then the row line R'1 is selected, a write voltage Vp is impressed to the write circuit of a space row buffer circuit 13, then an input data is written to the memory cell of the row line R'1. When the address designation of A0-Ai=0 is performed to a memory cell array 10, a spare row decoder 11 and a spare row buffer circuit 13 select automatically the row line R'1.</p> |
