ABSTRACT
Since the advent of the electronic computer, users have been cursing the limitations of this particular type of device. The processor needs to have access to a memory unit. The problem is that accessing memory is slow, compared to the speed at which Arithmetic Logic Shift Unit operations can be performed. A common technique used to improve the performance of the data fetches involves placing a small, specialized memory unit, called a cache unit, in the processor. The cache must be small enough so that its inclusion in the processor does not significantly degrade the performance of the processor. The cache unit is loaded with data that might be needed in the near future. The defining characteristic of direct mapped caching is that any given datum is always stored at a fixed location in the cache unit. When the processor gets an instruction to write to a memory location, it looks in the cache to determine what to do.
