Advantages of CISC architecture
- Microprogramming is easy assembly language to implement, and less expensive than hard wiring a control unit.
- The ease of microcoding new instructions allowed designers to make CISC machines upwardly compatible:
- As each instruction became more accomplished, fewer instructions could be used to implement a given task.
Disadvantages of CISC architecture
- The performance of the machine slows down due to the amount of clock time taken by different instructions will be dissimilar
- Only 20% of the existing instructions is used in a typical programming event, even though there are various specialized instructions in reality which are not even used frequently
- The conditional codes are set by the CISC instructions as a side effect of each instruction which takes time for this setting – and, as the subsequent instruction changes the condition code bits – so, the compiler has to examine the condition code bits before this happens
