1. A system for caching data comprising: a cache memory for storing a copy of a portion of data stored in a system memory; a cache load circuit capable of retrieving the portion of data from the system memory and of storing a copy of the retrieved portion of data in a cache memory; a pre-fetch memory for storing a value; and a monitoring component for monitoring when a value has been written to the pre-fetch memory, wherein the system is arranged such that when the monitoring component for monitoring determines that a value has been written to the pre-fetch memory, the cache load circuit retrieves the portion of data stored in the system memory at a memory address defined by the written value, and stores the retrieved portion of data in the cache memory.