Methods and apparatus are provided for supplying data to a processor in a digital processing system. The method includes holding data required by the processor in a cache memory, supplying data from the cache memory to the processor in response to processor requests, performing a cache line fill operation in response to a chache miss, supplying data from a prefetch buffer to the cache memory in response to the cache line fill operation, and speculatively loading data from a lower level memory to the prefetch buffer in response to the cache line fill operation.