US Patent 7640397 Adaptive comparison control in a memory

A memory has multiple memory rows 32 storing respective stored values. The stored values are divided into portions which may be shared by all stored values within the memory rows concerned. When such portions are so shared, then the comparison between an input value and the plurality of stored values can be performed using a base value stored within a base value register 30 rather than by reading the relevant portions of the memory rows. Thus, those relevant portions of the memory rows can be disabled and power saved.