Cache control apparatus and cache system control method

A cache control apparatus includes a data unit configured to store data on an index-specific basis, a tag unit configured to store, on the index-specific basis, a tag and a flag indicating whether the data has an uncorrectable error, and a control unit configured to refer to the flag, upon detecting a tag hit by performing a read access to the tag unit, to determine whether an uncorrectable error exists in the data corresponding to the tag hit, wherein the control unit performs process scheduling such that the read access to the tag unit and another access to the tag unit are performed simultaneously.