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- CISC: Manchester Baby, EDVAC, EDSAC, BINAC, UNIVAC I, IBM 704, IBM 650, IBM 305, IBM AN/FSQ-7, IBM 7090, IBM 1620, IBM 1401, DEC PDP-1, Apollo Guidance Computer, IBM System/360, UNIVAC 1107, DEC PDP-8, DECSYSTEM-10, Intel 4004, Intel 8008, Intel 8080, Zilog Z-80, Zilog Z-8000, DEC PDP-11, Data General Nova, Motorola 68000, Intel Pentium, DEC VAX
- RISC: CDC 6600, CDC 7600, Cray-1, Cray-2, Cray-3, Sparc, IBM RISC, IBM POWER, Intel i960, MIPS, Motorola 88000, DEC Alpha, PowerPC, ARM
Note: CISC was very important when memory was small and very expensive as it allowed programs to be reduced in size. It was also very important when more programming was done with assembly languages than with high order languages as it made for instructions that were easy for programmers to understand. But with declining memory costs and almost all programming being done with compilers, research showed that that most of the instructions in a CISC instruction set were redundant and not needed. Eliminating them and reducing the instruction set to just a core of essential instructions allowed for both a significant reduction in the hardware needed to build a computer and the development of simpler more powerful compilers. With less hardware in the computer optimizing its design for higher speeds became much easier. Thus the concept of RISC was formed.
The CDC machines and the Cray-1 listed above were designed before the concept of RISC formally existed, but clearly meet its definition in retrospect. Designed by Seymour Cray, his primary goal was to produce the fastest computer possible at the time, which required elimination of all unnecessary hardware that might limit the speed of the machine. He even eliminated all data synchronization latches/registers, instead using hand tuned delay lines made of loose hanging loops of twisted pair to make sure signals arrived where needed at exactly the right time.
CISC - Means Complex instruction set architecture. A CISC system has complex instructions such as direct addition between data in two memory locations. Eg.8085
- Instruction Set:large set of instruction with variable size (16 to 64)
- Addressing Modes: 12-24
- General Purpose registers: 8-24
- Clock rate: 33-50MHz in 1992
RISC - Means Reduced Instruction Set Computer. A Risc system has reduced number of instructions and more importantly it is load store architecture were pipelining can be implemented easily. Eg.ATMEL AVR
- Instruction Set:Small set of instruction with fixed size (32-bit)
- Addressing Modes: 3-5
- General Purpose registers: 32-192
- Clock rate: 50-150MHz in 1993
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Is 8085 cisc or risc?
RISC is faster than CISC
Is Pentium 4 a cisc or risc?
RISC
Is pic microcontroller a cisc or risc?
risc
Dsp architecture cisc or risc?
risc
Pentium 4 use risc or cisc?
CISC
Are Pentium 1 Risc Processors or Cisc?
Pentium I processors are CISC.
Which two categories are used to classify CPU architecture?
CISC and RISC are the two categories that are used to classify CPU architecture. CISC is an acronym for complex instruction set computer.
8086 is risc or cisc based architecture?
The 8086/8088 is a CISC based architecture.
Please can someone give me the answera) Identify any FOUR 4 drawbacks of a CISC processor compared to a RISC processor?
In CISC, the instruction set is very large that can be used for complex operations while in RISC the instruction set is reduced, and most of these instructions are very primitive. CISC computer's execution time is very high whereas RISC computer's execution time is very less. In, CISC code expansion is not a problem while in RISC code expansion may create a problem. In CISC, decoding of instructions is complex whereas, in RISC, the decoding of instructions is simple. CISC requires external memory for calculations, but RISC requires external memory for calculations. CISC has only a single register set while RISC has multiple register sets are present.
Which has less number of instruction risc or cisc?
RISC stands for Reduced Instruction Set Computer. The design strategy of a RISC processor includes limiting the number of instructions. This does not mean that ALL RISC processors have less instructions than ALL CISC processors, but in general, they do.
Is 8051 a cisc or risc?
8051 is a CISC but having less number of instruction as comared to ARM which is RISC.CISC
What do RISC and CISC stand for?
CISC: Complex Instruction Set ComputerRISC: Reduced Instruction Set Computer
