CISC
E637384
CISC (Complex Instruction Set Computer) is a type of computer architecture characterized by a large, rich set of instructions that can execute complex operations in a single command, often used to enhance code density and ease of programming.
Statements (48)
| Predicate | Object |
|---|---|
| instanceOf |
computer architecture
ⓘ
instruction set architecture ⓘ |
| aimsTo |
improve code density
ⓘ
reduce number of instructions per program ⓘ simplify assembly language programming ⓘ |
| canProvide |
better code density than RISC
ⓘ
shorter programs in assembly ⓘ |
| characterizedBy |
complex instructions
ⓘ
high code density ⓘ instructions that perform multi-step operations ⓘ large instruction set ⓘ microcoded control ⓘ support for complex addressing modes ⓘ variable-length instructions ⓘ |
| comparedTo | Reduced Instruction Set Computer NERFINISHED ⓘ |
| contrastedWith | RISC NERFINISHED ⓘ |
| designPhilosophy |
fewer instructions per program
ⓘ
hardware handles complex operations ⓘ |
| emergedIn | 1970s ⓘ |
| exampleArchitecture |
Motorola 68000
NERFINISHED
ⓘ
System/360 NERFINISHED ⓘ |
| exampleArchitecture |
VAX
NERFINISHED
ⓘ
x86 NERFINISHED ⓘ |
| fullName | Complex Instruction Set Computer NERFINISHED ⓘ |
| hasAcronym | CISC NERFINISHED ⓘ |
| historicallyUsedIn |
early microprocessors
ⓘ
mainframe computers ⓘ minicomputers ⓘ |
| influencedBy | microprogramming techniques ⓘ |
| mayInclude |
complex arithmetic instructions
ⓘ
instructions for procedure calls ⓘ stack-oriented instructions ⓘ string manipulation instructions ⓘ |
| oftenImplements | instructions via microcode ⓘ |
| optimizationFocus |
minimizing memory usage
ⓘ
supporting rich instruction semantics ⓘ |
| supports |
complex memory access patterns
ⓘ
high-level language constructs in hardware ⓘ |
| tradeOff |
more complex hardware
ⓘ
more complex instruction decoding logic ⓘ potentially lower clock speeds in early designs ⓘ |
| typicallyHas |
complex instruction decoding
ⓘ
instructions with multiple cycles ⓘ many addressing modes ⓘ |
| usedFor |
desktop processors
ⓘ
general-purpose computing ⓘ server processors ⓘ |
| wasDominantIn | 1980s ⓘ |
Referenced by (4)
Full triples — surface form annotated when it differs from this entity's canonical label.