Revision as of 07:45, 6 September 2005 edit Brouhaha (talk \| contribs) Extended confirmed users 1,394 edits Added overview section in attempt to clarify the general concept, in response to comments on the Talk page. ← Previous edit		Revision as of 16:53, 7 September 2005 edit undo Atlant (talk \| contribs) Administrators 33,304 edits Typo; expand bug-fix concept. Next edit →
Line 2: ==Overview and benefits== A microprogrammed processor is a processor whose hardware implements a different (usually simpler) [[Computer architecture\|architecture]] than that which is visible to the normal programmer; that simpler architecture (the microarchitecture) is used to ~~executes~~execute a microprogram that implements the programmer-visible architecture. ~~The~~For example, the IBM System/360 has a 32-bit architecture with 16 general-purpose registers, but most of the System/360 implementations actually used hardware implementing a much simpler underlying microarchitecture. The 360 Model 30 used an 8-bit processor with only a few hardware registers; most other models used 16-bit or 32-bit processors. Microprogramming enabled IBM to design many System/360 models with substantially different hardware and spanning a wide range of cost and performance, while making them all architecturally compatible. This dramatically reduced the amount of unique system software that had to be written for each model. Microprogramming also reduced the cost of field changes to correct defects ([[Computer bug\|bug]]s) in the processor; a bug could often be fixed by replacing a portion of the microprogram rather than by changes being made to hardware logic and wiring. ==History==

Microcode: Difference between revisions