| ISA: Types | ||||||||||||||
| Types of architectures | ||||||||||||||
| CISC: complex instruction set computer | ||||||||||||||
| Traditional computer architecture | ||||||||||||||
| Unique instructions for as many operations as possible | ||||||||||||||
| Advantages | ||||||||||||||
| Each instruction can do more work | ||||||||||||||
| Programs use less memory | ||||||||||||||
| Easier to program directly or to write compilers | ||||||||||||||
| Disadvantages | ||||||||||||||
| More complex hardware circuits | ||||||||||||||
| More expensive to develop and build | ||||||||||||||
| Usually slower | ||||||||||||||
| RISC: reduced instruction set computer | ||||||||||||||
| Developed from research in late '70's/early '80's at IBM, Stanford, and UC-Berkeley | ||||||||||||||
| Look at actual instruction use, focus on most frequent ones | ||||||||||||||
| Advantages | ||||||||||||||
| Easier to learn | ||||||||||||||
| Simpler circuits | ||||||||||||||
| Cheaper and more reliable to design and build | ||||||||||||||
| Faster | ||||||||||||||
| Disadvantages | ||||||||||||||
| Larger, more complex programs | ||||||||||||||
| Harder to program | ||||||||||||||
| Depends on compiler for optimization | ||||||||||||||