Cache error code update

摘要

A system for updating an ECC code over a line in a data store when only part of the line has been updated is described. The system receives the update and its address, decodes the address to generate a first signal identifying the part of the line to be updated and a second signal identifying an un-updated part of the section. The data of the update and the first signal are used to generate a first partial error code. Data from the un-updated part of the line is read as the update is written to the store. The data from the un-updated part of the section and the second signal are used to generate a second partial error code. Finally, the first and second partial error codes are combined to generate the updated error code.