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

Explain about floating point representation, Q. Explain about Floating Poin...

Q. Explain about Floating Point Representation? Floating-point number representation includes two parts. The first part of number is a signed fixed-point number which is called

Need of the assembly language, Q. Need of the assembly language ? Machi...

Q. Need of the assembly language ? Machine language code comprises the 0-1 combinations which computer decodes directly.  Though the machine language has the following problems

Sorting algorithms, Two way merge sort for 84,83,78,90,23,123,98,159,8,200

Two way merge sort for 84,83,78,90,23,123,98,159,8,200

Critical capabilities for superior firm performance, What are the critical ...

What are the critical capabilities for superior firm performance in e-commerce? Three firm capabilities which are critical for superior firm performance within e-commerce are:

Briefly define the term isotype, Question: (a) (i) Briefly define the t...

Question: (a) (i) Briefly define the term "Isotype". (ii) With the help of diagrams, describe the rules of "Isotype". (b) Elaborate on your understanding of internationa

Two independent mechanisms for controlling interrupt request, What are the ...

What are the two independent mechanisms for controlling interrupt request? At the device end, an interrupt enable bit in a control register verifies whether the device is permi

SGML, Write short note of SGML

Write short note of SGML

Why is xml such an important development, It takes away two constraints whi...

It takes away two constraints which were holding back Web developments: 1. Dependence on a one, inflexible document type (HTML) which was being much abused for tasks it was neve

Software, S oftware In 1970s less than 1 percent of the public could h...

S oftware In 1970s less than 1 percent of the public could have intelligently explained what "computer software " means. Nowadays most professionals and various member of the

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