PURPOSE: To provide a variable memory length device whose mounting area is relieved.

CONSTITUTION: This programmable variable memory length device is constituted of n×m memory cells 1a to 1n to ma to mn forming a matrix so as to optionally connect/disconnect respective passes in n columns × m lines by dividing a memory device into n×m parts and arraying the divided parts in n columns ×m rows, an address forming part 20 for forming a prescribed address by an address for addition control and an address corresponding to the n-th array memory cell and plural adders 22a to 22n to 2ma to 2mn for forming addresses corresponding to the variable memory lengths of n×m memory cells.