Programmable microcode unit for mapping plural instances of an instruction in plural concurrently executed instruction streams to plural microcode sequences in plural memory partitions

摘要

A method and circuit arrangement utilize a programmable microcode unit that is capable of being programmed via software to modify the instruction sequences output by the microcode unit in response to microcode instructions issued to the microcode unit. Multiple instruction sequences may be stored in different partitions defined in one or more rewriteable memories such that different instruction sequences may be output for different instances of a microcode instruction executing in different, concurrently-executing instruction streams.