|
|
CISC Processors
(Complex Instruction Set Computing)
This class of microprocessors have characteristics that fit most early
microprocessor designs. As such their characteristics consisted of
practical design choices for the time that they were invented (around the
1970's). For some applications, the rate at which data can
be fetched from memory is a limiting factor to the performance of the application.
These types of applications are still well suited to the design guide lines
of CISC processors. Two common design choices that reduce High
Memory Overhead are:
Another common attribute to CISC processors is support for some programming
sequences that:
-
Hinder a processor's performance
-
Occur rarely
-
Could have been initialy defined as producing unpredictable results
Frequently this support occur because we didn't know the preformance implications
the sequence would have on future design choices. One of the significant
examples of this is support for Self Modifying
Code.
|
|
