Methods and apparatus for controlling a cache memory

A method for controlling a cache (110, 110A) memory, comprising the steps of: receiving (300) an address (204) to at least one of the options of writing data to and retrieve data from the cache, including label address bits and index bits; accessing (302) one or more cache lines (200) corresponding to the cache index bits of the address; each cache line including an address label (210), a data validity flag (212A) and a flag data type (212B); determining (304) whether data in at least one of the one or more cache lines is valid based on the validity flag data; determining (312) what type of data is stored in at least one cache line based on the flag data type; and prohibit (322) overwriting floating point data in the at least one cache line when the same data are valid and the data stored in the at least one cache line are integer data.