Patent ID: 7117420

Claim:
An apparatus for memory error control coding comprising: a syndrome encoder circuit configured to (i) receive a read data signal and a read parity signal and (ii) generate a first syndrome signal in response to said read data signal and said read parity signal; a bypass circuit configured to (i) receive said first syndrome signal and a bypass signal and (ii) generate a second syndrome signal in response to said first syndrome signal and said bypass signal, wherein said bypass circuit comprises one or more logic gates configured to (i) receive said first syndrome signal at a first input, (ii) receive said bypass signal at a second input and (iii) present said second syndrome signal at an output; a detector circuit configured to (i) receive said second syndrome signal, (ii) detect an error when bits of said second syndrome signal are not all the same state and (iii) generate one or more single error signals when a single bit error is detected in said read data and said read parity signals, a double error signal when an error is detected in two bits of said read data and read parity signals, and an error detected signal when either one of said one or more single error signals or said double error signal are asserted in response to said second syndrome signal; a locator circuit configured to (i) receive said second syndrome signal and (ii) generate an error location signal in response to said second syndrome signal, wherein said error location signal (i) is generated in response to fewer than all of said bits of said second syndrome signal and (ii) describes a location of a single bit error detected in said read data and said read parity signals; and a corrector circuit configured to (i) receive said read data signal, said read parity signal, said error location signal and said one or more single error signals and (ii) generate a corrected representation of said read data and said read parity signals in response to said error location signal when a single bit error is detected.