Data processor with improved microprogramming

摘要

Improved means and methods are described for providing microprogramming in a microprogrammed data processor. A separate, relatively fast access Read/Write microinstruction memory is provided which operates as an index-associative cache memory with respect to the processor main memory in a manner which permits a high "hit" ratio to be obtained for requested microinstructions, while at the same time removing the burden from the programmer of having to be concerned with the loading and/or current contents of the microinstruction memory.