Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Q. What is Random Access Memory?
We will discuss RAM as an example of sequential circuit. A memory unit is a collection of storage cells or flip flops along with associated circuits needed to transfer information in and out of device. The access time and cycle time it takes are constant and independent of location therefore the name random access memory.
Figure: Binary Cell
RAMs are arranged (logically) as words of fixed length. Memory communicates with other devices by data input and output lines and address selection lines and control lines which specify direction of transfer.
Now let's try to understand how data is stored in memory. The internal construction of a RAM of 'm' words and 'n' bits per word comprises m ×n binary cells and connected circuits for detecting particular words. Figure below displays logic diagram and block diagram of a binary cell.
The input is fed to AND gate 'a' in complemented form. Read operation is denoted by 1 on read/write signal. Thus during read operation only 'AND' gate 'c' becomes active. If cell has been selected then output will become equivalent to state of flip flop it implies that data value stored in flip flop is read. In write operation 'a' & 'b' gates become active and they set or clear J-K flip flop relying upon input value. Please note in case input is 0 then flip flop will go to reflected in state of flip-flop. So we say that input data has been stored in flip-flop or binary cell.
Figure below is extension of this binary cell to an IC RAM circuit where a 2×4 decoder is used to select one of the four words. (For 4 words we require 2 address lines) Please note that every decoder output is connected to a 4 bit word and read/write signal is given to every binary cell. Once decoder selects word, read/write input tells operation. This is derived using an OR gate since all non-selected cells will generate a zero output. When memory select input to decoder is 0 none of words is selected and contents of cell are unchanged irrespective of read/write input.
Figure: 4 × 4 RAM
Scoreboards- Constrained-Random Verification Methodology Scoreboards are used to verify that data has successfully reached its destination whereas monitors snoop the interfaces
i need algorithm for padovan string
What are the Objectives of UML trace development of UML; recognize and describe notations for object modelling using UML; describe a variety of structural and be
Boolean algebra. Boolean algebra mathematical method based on human reasoning. In Boolean algebra only two states exist; true and false which are written as 1 (true) and 0 (fa
Q. Main drawbacks of CD-ROMs? The main drawbacks of CD-ROMs are: It is read only thus can't be updated Access time is longer than that of magnetic disks. Very
How call processing takes place? Fundamental Call Procedure: Fig. demonstrates a simplification diagram exemplifying how two telephone sets (as subscribers) are interconnecte
Before we take a detailed look about the Motorola 68HC11 series of micro controllers it is useful to define what is meant by a micro controller. As the name suggests a micro contro
What are universal gates. Construct a logic circuit using NAND gates only for the expression x = A . (B + C). Ans. Universal Gates: NAND and NOR Gates both are t
Q. Explain Microcode and VLSI Technology? It is considered that CU of a computer be assembled using two ways; create micro-program which execute micro-instructions or construct
Disc shapes and diameters: A Mini-CD is 8 centimeters in diameter. The digital data on a CD start at the center of the disc and proceeds toward the edge, whi
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!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd