CIRCUIT FOR CHANGING STRUCTURE OF MEMORY CELL BLOCK

摘要

PURPOSE: A circuit for changing a structure of a memory cell block is provided to use the remaining block after discarding a fail block when a repairing of large-sized memory is impossible by a redundancy operation, and effectively uses a memory. CONSTITUTION: A circuit for changing a structure of a memory cell block includes a first fuse(10), a second fuse(20), a second transmission gate(X2), and an address buffer(30). The first fuse(10) performs a normal addressing if all memory cell blocks are normal, performs a fuse-cut if a repairing of the memory is impossible by a redundancy, makes the addressing impossible. The second fuse(20) performs an addressing with a repairable memory when a memory cell block that is impossible to be repaired by a redundancy. The first transmission gate(X1) transmits/or cuts off an address of the first fuse(10). The second transmission gate(X2) transmits/or cuts off an address of the second fuse(20). The address buffer(30) buffers signals transmitted from the first transmission gate(X1) and the second transmission gate(X2).