A re-fetching cache memory improves efficiency of a system, for example by advantageously sharing the cache memory and/or by increasing performance. When some or all of the cache memory is temporarily used for another purpose, some or all of a data portion of the cache memory is flushed, and some or all of a tag portion is saved in an archive. In some embodiments, some or all of the tag portion operates “in-place” as the archive, and in further embodiments, is placed in a reduced-power mode. When the temporary use completes, optionally and/or selectively, at least some of the tag portion is repopulated from the archive, and the data portion is re-fetched according to the repopulated tag portion. According to various embodiments, processor access to the cache is enabled during one or more of: the saving; the repopulating; and the re-fetching.