Method and apparatus for generating an echo clock in a memory

Abstract

A method and apparatus for generating an echo clock is described. An echo clock is an output strobe signal that selectively follows an input clock signal in a synchronous memory system and indicates when valid output data is available. The same clock signals used to change the state of an echo clock are used to output data from a memory buffer. The data buffer and echo clock buffer/generator are substantially identical in construction and operation, thereby ensuring a close correlation between a change in state of the echo clock and the availability of valid data. Such a memory provides matching of the echo clock transitions with that of the data signals on the data lines of the memory for any frequency range.