The Effects - of Emerging Technology and Emulation ; ERequirements orn Microprogramming

The structure of microprogrammed processors is largely determined by the state of (semiconductor) technology and the requirements of the task of emulation. We discuss the impact of LSI components on microprogrammable processors and in particular, the effect of large memory arrays, LSI microprocessors (bit-slices), programmable logic arrays, and high-speed shifters. A secondary theme of this article is that microprogramming differs very little from "regular" programming. We argue that the right approach to understanding microprogranning is to recognize that it is primarily applied to the task of emulation. We review the requirements of the emulation (interpretation) task and indicate what capabilities a microprogrammable processor needs to have in order to make the process of emulation efficient. We conclude with a taxonomy of microprogrammable processors.