Working of read-only memory, Computer Engineering

Assignment Help:

Q. Working of Read-Only Memory?

A ROM is fundamentally a memory or storage device in which a fixed set of binary information is stored. A block diagram of ROM is as displayed in Figure. It comprises n input lines and m output lines. Every bit combination of input variables is known as an address. Every bit combination which comes out of output lines is known as a word. Total number of bits per word is equal to number of output lines m. Number of distinct addresses possible with n input variables is 2n.

79_Working of Read-Only Memory.png

Figure: ROM

A ROM is characterised by number of words (2n ) and number of bits (m) per word. For illustration a 32 × 8 ROM that can be written as 25 × 8 comprises 32 words of 8 bit each that means there are 8 output lines and 32 distinct words stored in unit. There are only 5 input lines since 32 = 25and with 5 binary variables we can specify 32 addresses.  

A ROM is fundamentally a combinational circuit and can be constructed as displayed in Figure below. On applying an Input I1 = 0, I2 = 0 the 00 line of decoder is selected and we will get O1 = 0 and O2 = 1 on applying I1 = 0 and I2 = 1 we will obtain O1 = 1 AND O2 = 0. This same logic can be used for creating larger ROMs.


Related Discussions:- Working of read-only memory

Benefits of having densely packed integrated circuits, What are benefits of...

What are benefits of having densely packed Integrated Circuits? These are stated below: Reliability: The integrated circuit interconnections are in fact more reliable

The 2''s complement of the decimal number, What is the 2's complement of th...

What is the 2's complement of the number 1101101 ? Ans. 0010011 is the 2's complement of the number 1101101. As 1's complement of the number 1101101 is 0010010 and 2's comple

Opcode field of an instruction, For this machine there can be two more poss...

For this machine there can be two more possible addressing modes in addition to direct andimmediate.   Opcode field of an instruction is a group of bits which define various pro

Program, Write a program to find the area under the curve y = f(x) between ...

Write a program to find the area under the curve y = f(x) between x = a and x = b, integrate y = f(x) between the limits of a and b. The area under a curve between two points can b

RISC performance using optimizing compilers, Q. RISC Performance using opti...

Q. RISC Performance using optimizing compilers? Performance using optimizing compilers: As instructions are simple compilers can be developed for efficient code organization a

Efficiency of vector processing over scalar processing, Efficiency of Vecto...

Efficiency of Vector Processing over Scalar Processing: We know that, a sequential computer processes scalar operands one at a time. Thus, if we have to process a vector of len

Problems for decision tree learning, A ppropriate Problems for Decision Tr...

A ppropriate Problems for Decision Tree Learning - Artificial intelligence It is a expert job in AI to select accurately the right learning representation for a particular lea

TIME COMPLEXITY, calculate the time complexity of a=(b/c) operation in stac...

calculate the time complexity of a=(b/c) operation in stack

Design an or to and gates combinational network, Q. Design an OR to AND gat...

Q. Design an OR to AND gates combinational network for the following Boolean expression:   ABCD + A'BC'D + A'BC'D' + A'BCD + (A'B'C'D' + AB'CD) Two terms in parenthesis are Don

What are the disadvantages of bespoke software, What are the disadvantages ...

What are the disadvantages of Bespoke Software -  Very dependent on suppliers of the software; if they go out of business there would be little or no support if problems occ

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd