Clocking scheme for independently reading and writing multiple width words from a memory array

Abstract

The present invention provides a circuit for writing a particular sized data word from a common input to a number of individual memory cells in a memory array and reading a particular sized data word from the individual memory cells to a common output. The size of the word written to the memory cells can be larger, smaller or the same as the size of the word read from the memory array. The present invention uses a multi-bit write counter to distribute a write timing signal to a number of multiplexer blocks and a multi-bit read counter to distribute a read timing signal to a number of sense amplifier blocks. Each of the multiplexer blocks receives both a data input signal from the common input and the write timing signal continuously when the circuit is in operation. Each of the sense amplifier blocks receives data from the memory array and a read timing signal at all times. When a particular read timing signal is present at a sense amplifier, the output signal containing a fixed width data word is received from one or more of the corresponding memory arrays and is presented to the common output. The present invention reduces the number of internal signal lines necessary to implement the control function and allows for easy modification to both read and write multiple width words to and from the memory array.