Address signal generating circuit for a memory circuit

Abstract

An address signal generating circuit for a memory circuit comprises a first latch driver for producing a signal corresponding to upper m bits of a 2m-bit address signal which is to be generated, where m is an integer, a second latch driver for producing a signal corresponding to lower m bits of the 2m-bit address signal, a circuit for dividing a 2m-bit signal which has a predetermined value into upper m bits and lower m bits and for alternately producing signals corresponding to the upper and lower m bits, a first adder for adding the value of n bits in the signal which has the predetermined value and the value of upper n bits in an output signal of the first or second latch driver and for producing an n-bit signal, where n is an integer less than m, a second adder for adding the value of m-n bits in the signal which has the predetermined value and lower m-n bits of the output signal of the first or second latch driver and for producing an (m-n)-bit signal, an adding circuit for supplying a carry signal of the first or second adder to the second or the first adder so as to add the carry signal with another input signal of the second or the first adder, and a driver control circuit for controlling the first and second latch drivers to alternately and time-divisionally produce upper m bits of the 2m-bit address signal and lower m bits of the 2m-bit address signal by alternately latching an m-bit output signal of the first and second adders in the first and second latch drivers.