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MAIN MEMORY

Main Memory The main memory acts as the central storage unit in a computer system. It is a relatively large and fast memory which is used to store programs and data during the run time operations. The primary technology used for the main memory is based on semiconductor integrated circuits. The integrated circuits for the main memory are classified into two major units. RAM (Random Access Memory) integrated circuit chips ROM (Read Only Memory) integrated circuit chips RAM integrated circuit chips The RAM integrated circuit chips are further classified into two possible operating modes,  static  and  dynamic . The primary compositions of a static RAM are flip-flops that store the binary information. The nature of the stored information is volatile, i.e. it remains valid as long as power is applied to the system. The static RAM is easy to use and takes less time performing read and write operations as compared to dynamic RAM. The dynamic RAM exhibits...

Memory Hierarchy

Memory Hierarchy A memory unit is an essential component in any digital computer since it is needed for storing programs and data. Typically, a memory unit can be classified into two categories: The memory unit that establishes direct communication with the CPU is called  Main Memory . The main memory is often referred to as RAM (Random Access Memory). The memory units that provide backup storage are called  Auxiliary Memory . For instance, magnetic disks and magnetic tapes are the most commonly used auxiliary memories. Apart from the basic classifications of a memory unit, the memory hierarchy consists all of the storage devices available in a computer system ranging from the slow but high-capacity auxiliary memory to relatively faster main memory. The following image illustrates the components in a typical memory hierarchy. Auxiliary Memory Auxiliary memory is known as the lowest-cost, highest-capacity and slowest-access storage in a computer system....

CISC AND RISC PROCESSOR

RISC and CISC Processors RISC stands for  Reduced Instruction Set Computer and CISC stands for  Complex Instruction Set Computer . There are two approaches of the design of the control unit of a microprocessor i.e.- Hardware approach and Software approach. RISC Processors:-  To execute an instruction, a number of steps are required. By the control unit of the processor, a number of control signals are generated for each step. To execute each instruction, if there is a separate electronic circuitry in the control unit, which produces all the necessary signals, this approach of the design of the control section of the processor is called  RISC  design. It is hardware approach. It is also called hard-wired approach. Examples of RISC processors are: DEC's Alpha 21064, 21164 and 21264 processors; SUN's SPARC and ULTRA SPARC; PowerPC processors etc. CISC Processors:-  If the control unit contains a number of micro electronic circuitry to ge...