Data cache with modified bit array

A method for accessing a cache memory system, the method comprising:

• storing a cache line in each storage element of a first array of storage elements;
• storing into each storage element of a second array of storage elements corresponding to the first array of storage elements a first partial status of the cache line in the corresponding storage element of the first array;
• storing into each storage element of a third array of storage elements corresponding to the first array of storage elements a second partial status of the cache line in the corresponding storage element of the first array, wherein the second partial status indicates whether or not the cache line has been modified;
• in response to modifying the cache line within a storage element of the first array, writing only the second partial status in the corresponding storage element of the third array to indicate that the cache line has been modified, but refraining from writing the first partial status in the corresponding storage element of the second array;
• determining the full status of the cache line by reading both the first partial status and the second partial status of the cache line from corresponding storage elements of the second array and the third array, respectively.

A computer program product for use with a computing device, the computer program product comprising:

• a computer usable storage medium, having computer readable program code embodied in said medium, for specifying cache memory system, the computer readable program code comprising:
• first program code for specifying a first array of storage elements, each configured to store a cache line;
• second program code for specifying a second array of storage elements corresponding to the first array of storage elements, each configured to store a first partial status of the cache line in the corresponding storage element of the first array;
• and
• third program code for specifying a third array of storage elements corresponding to the first array of storage elements, each configured to store a second partial status of the cache line in the corresponding storage element of the first array, wherein the second partial status indicates whether or not the cache line has been modified;
• wherein when the cache memory system modifies the cache line within a storage element of the first array, the cache memory system writes only the second partial status in the corresponding storage element of the third array to indicate that the cache line has been modified but refrains from writing the first partial status in the corresponding storage element of the second array;
• wherein the cache memory system reads both the first partial status and the second partial status of the cache line from corresponding storage elements of the second array and the third array, respectively, to determine the full status of the cache line.