Gray code counter with error detector in a memory system

摘要

An improved dynamic memory system including through-checking and error detection of the refresh counter is described. A refresh counter that provides parity of the refresh count for through-checking, of refresh addresses is shown. Error detecting circuitry is utilized in conjunction with the refresh counter and the parity generating circuitry to detect errors in functionality of the refresh counter. The refresh counter is a Gray code counter constructed of a double rank of latches operable with code generating logic circuits for determining the sequence of generation of Gray code groupings.