Q.1. What is CISC Microprocessor?
Ans.: CISC stands for complex instruction set computer. It was developed by Intel. CISC is a type of design for the computers. CISC based computer will have shorter programs which are made up of symbolic machine language. The number of instructions on a CISC processor is more.
Q.2. What is RISC Microprocessor?
Ans.: RISC stands for reduced instruction set computer architecture. The properties of this design are :
(i) A large number of general purpose registers and use of computers to optimize register usage.
(ii) A limited & simple instruction set.
(iii) An emphasis on optimizing the instruction pyre line.
Q.3. What are the different types of Memory?
Ans.: The memory in a computer is made up of semi-conductions. Semi-conduction memories are of two types :
(1) RAM : Random Access Memory
(2) ROM : Read Only Memory
(1) RAM : The Read and write (R/W) memory of a computer is called RAM. The User can write information to it and read information from it. In Random Access, any memory location can be accessed in a random memory without going through any other memory location. The RAM is a volatile memory, it means information written to it can be accessed as long as power is on. As soon as the power is off, it can not be accessed.
There are two basic types of RAM :
(i) Static RAM
(ii) Dynamic Ram
(i) S-RAM retains stored information only as long as the power supply is on. Static RAM‟s are costlier and consume more power. They have higher speed than D-RAMs. They store information in Hip-Hope.
(ii) D-RAM loses its stored information in a very short time (for milli sec.) even when power supply is on. In a DRAM, a binary static is stored on the gate to source stray capacitor of a transfer the presence of charge on the stray capacitor shows 1 & absence 0.
D-RAM‟s are cheaper & lower.
Some other RAMS are :
(a) EDO (Extended Data Output) RAM : In an EDO RAMs, any memory location can be accessed. Stores 256 bytes of data information into latches. The latches hold next 256 bytes of information so that in most programs, which are sequentially executed, the data are available without wait states.
(b) SDRAM (Synchronous DRAMS), SGRAMs (Synchronous Graphic RAMs) : These RAM chips use the same clock rate as CPU uses. They transfer data when the CPU expects them to be ready.
(c) DDR-SDRAM (Double Data Rate – SDRAM) : This RAM transfers data on both edges of the clock. Therefore the transfer rate of the data becomes doubles.
(2) ROM : Read only memory: Its non volatile memory, ie, the information stored in it, is not lost even if the power supply goes off. It‟s used for the permanent storage of information. It also posses random access property. Information can not be written into a ROM by the users/programmers. In other words the contents of ROMs are decided by the manufactures.
The following types of ROMs an listed below :
(i) PROM : It‟s programmable ROM. Its contents are decided by the user. The user can store permanent programs, data etc in a PROM. The data is fed into it using a PROM programs.
(ii) EPROM : An EPROM is an erasable PROM. The stored data in EPROM‟s can be erased by exposing it to UV light for about 20 min. It‟s not easy to erase it because the EPROM IC has to be removed from the computer and exposed to UV light. The entire data is erased and not selected portions by the user. EPROM‟s are cheap and reliable.
(iii) EEPROM (Electrically Erasable PROM) : The chip can be erased & reprogrammed on the board easily byte by byte. It can be erased with in a few milliseconds. There is a limit on the number of times the EEPROM‟s can be reprogrammed, i.e.; usually around 10,000 times.
Flash Memory : Its an electrically erasable & programmable permanent type memory. It uses one transistor memory all resulting in high packing density, low power consumption, lower cost & higher reliability.
It‟s used in all power, digital cameras, MP3 players etc.