A complex instruction set computer (CISC, pronounced like "sisk") is a computer instruction set architecture (ISA) in which each instruction can execute several low-level operations, such as a load from memory, an arithmetic operation, and a memory store, all in a single instruction. The term was retroactively coined in contrast to reduced instruction set computer (RISC).
Examples of CISC processor families are System/360, PDP-11, VAX, 68000, and...
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A complex instruction set computer (CISC, pronounced like "sisk") is a computer instruction set architecture (ISA) in which each instruction can execute several low-level operations, such as a load from memory, an arithmetic operation, and a memory store, all in a single instruction. The term was retroactively coined in contrast to reduced instruction set computer (RISC).
Examples of CISC processor families are System/360, PDP-11, VAX, 68000, and x86.
Before the RISC philosophy became prominent, many computer architects tried to bridge the so called semantic gap, i.e. to design instruction sets that directly supported high-level programming constructs such as procedure calls, loop control, and complex addressing modes, allowing data structure and array accesses to be combined into single instructions. Instructions are also typically highly encoded in order to further enhance the code density. The compact nature of such instruction sets results in smaller program sizes and fewer (slow)...
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