Method for correcting single bit hard errors

A method for correcting single bit hard errors in a stored digital data word of “n” bits, where n is a selected integer, comprising the steps of:

• I) storing an n-bit digital data word in a memory in response to a write command from a system including said memory, wherein storing said n-bit digital data word includes:
• a) generating a parity bit for said n-bit digital data word according to a predetermined algorithm prior to storing said n-bit digital data word;
• b) writing said n-bit digital data word in a selected storage location in said memory;
• and
• c) writing only said parity bit for each n-bit digital data word in said memory in addition to said n-bit digital data word;
• wherein only said n-bit digital data word and said parity bit are stored in said operation of storing said n-bit digital data word;
• II) retrieving said n-bit digital data word from said memory subsequent to completion of said storing and in response to a read command from said system, wherein retrieving said n-bit digital data word includes:
• d) reading said stored n-bit digital data word from said selected storage location in said memory;
• e) reading the stored parity bit for said n-bit digital data word;
• f) generating a new parity bit for said read n-bit digital data word according to said predetermined algorithm;
• g) comparing said new parity bit with said read parity bit;
• and
• h) error correcting said read n-bit digital data word only when,,said parity bits are different by
• i) inverting said read n-bit digital data word;
• ii) writing said inverted n-bit digital data word at said selected location in said memory;
• iii) reading said n-bit digital data word from said selected storage location in said memory;
• and
• iv) inverting said n-bit digital data word read from said selected location in said memory to obtain said n-bit digital data word without an error.