Definition of RISC and CISC

 RISC: RISC stands for Reduce instruction set computer, it has a very few instructions set with few addressing modes, use to reduce the set instruction.

 It executes much faster with in the CPU without use of memory.

 Characteristics

•  few instructions set
•  few addressing modes
•  fixed length of instructions set
•  does not support array
•  hardwired
•  single cycle instructions set

 Advantage of RISC

•  it helps in reducing instruction set
•  offers extensive addressing capability for memory management

 Disadvantage of RISC

•  due to continuously reprogrammed in hardware of chip its memory cache is large

 CISC: CISC stands for Critical instructions set computer, it is very large in instructions set with large addressing modes.

 Characteristics

•  larger instructions set
•  large addressing modes
•  variable length instructions format
•  support array
•  it has instructions that manipulate operands in memory

 Advantage of CISC

•  easy to add new command in the chip
•  this architecture allows you to do effective use of the main memory

 Disadvantage of CISC

•  performance of machine slow-down.
•  It requires more transistors.

 Difference between RISC and CISC

RISC and CISC are the part of reduced computer, it is very important part of computer architecture.

 In this topic we understand the designing of the instructions set of the processor, the instructions set choose for the particular computer determines the way by which the machine language programs are constructed.

 RISC Architecture

 Its Architecture contains: Hardwired control, Main Memory, Instruction cache, Data path, Data cache.

 Due to the separate setup of Data path and Data cache, the computer system run faster, and the performance speed is also very good.

 And using Hardwired control, it is easy to control and maintain the control unit of the chip.

 CISC Architecture

 Its Architecture contains: Control unit, Microprogrammed control unit, Instruction and Data path, cache memory, Main Memory.

 RISC Approach

 It is needed single instruction or command for executing the task like: ADD, SUB.

 CISC Approach

 It requires the suitable data and the instruction to perform the task at desired data and data location.

 Application of RISC

 RISC is used in high-end applications like: video processing, telecommunications, and image processing.

 Application of CISC

 CISC is used in low-end applications like: security, home automation.

 Note: CISC design is very complex, due to its complexity it is very secure and not easy to crack the security level, but RISC is not much secure as compare to CISC, RISC satisfied the user real requirement of program.

 RISC pipe lining does function correctly, whereas CISC pipe lining does not function correctly,

 RISC decoding is very simple, whereas the CISC decoding is very complex.

 RISC calculation is very fast and precise, whereas CISC calculation take time, and it is not very accurate.

 That is the complete explanation about reduced computer types that is RISC and CISC.

 In next article we understand about top 3 categories of instructions that are use in computer system for the processing of the data and also understanding the Addressing Mode.