Abstract:
Processors and systems having a micro tag array that reduces data cache access power. The processors and systems include a cache that has a plurality of datarams, a processor pipeline register (Fig. 4 Ref. 402), and a micro tag array (Ref. 410). The micro tag array is coupled to the cache and the processor pipeline register. The micro tag array stores base address data bits or base register data bits, offset data bits, a carry bit, and way selection data bits. When a LOAD or a STORE instruction is fetched, at least a portion of the base address and at least a portion of the offset of the instruction are compared to data stored in the micro tag array. If a micro tag array hit occurs, the micro tag array generates a cache dataram enable signal. This signal enables only a single dataram of the cache.
Abstract:
Microprocessor having a power-saving instruction cache way predictor and instruction replacement scheme. In one embodiment, the processor includes a multi-way set associative cache, a way predictor, a policy counter, and a cache refill circuit. The policy counter provides a signal to the way predictor that determines whether the way predictor operates in a first mode or a second mode. Following a cache miss, the cache refill circuit selects a way of the cache and compares a layer number associated with a dataram field of the way to a way-set-layer number. The cache refill circuit writes a block of data to the field if the layer number is not equal to the way-set-layer number. If the layer number is equal to the way-set-layer number, the cache refill circuit repeats the above steps for additional ways until the block of memory is written to the cache.