Explain the operation of 8279, Electrical Engineering

Assignment Help:

Explain the operation of 8279.  Explain the following terms:

(i)  N key Roll over.

(ii)  Key board debounce.

(iii)  FIFO RAM.

Ans

The 8279 microprocessor is a programmable keyboard and display interfacing component which scans and encodes up to a 64-key keyboard and controls up to a 16-digit numerical display. This keyboard interface has built in first-in first-out buffer which allows this store up to eight keystrokes before the microprocessor should retrieve a character. There display section controls up to 16 numeric displays by an internal 16 X 8 RAM which stores the coded display information.

The keyboard sections contain eight lines which can be connected to eight columns of a keyboard, and also two additional lines with to shift and CNTL/STB keys. These key pressed are automatically debounced and the keyboard can function in two modes two key lock out or n-key rollover. When two keys in the two -key lock out mode are pressed concurrently, only first key is identified. In the N-key roll over mode, concurrent key are recognized and their codes are stored into the internal buffer.


Related Discussions:- Explain the operation of 8279

Comparison of rs232c and rs422a standards, Explain explanatory notes on com...

Explain explanatory notes on comparison of RS232C and RS422A standards. Comparison of RS232C and RS422A standards: RS232C 1. Standard explained for asynchronous commu

Evaluate the four parameters of the hybrid model, Q. Show that any amplifie...

Q. Show that any amplifier represented by the model of Figure of the text can also be represented by themore general hybridmodel of Figure. Evaluate the four parameters of the hybr

Briefly explain about wheatstone bridge, Q. Briefly explain about Wheatston...

Q. Briefly explain about Wheatstone Bridge? Null measurements are made with bridge circuits and related configurations. They differ from direct measurements in that the quantit

Bode plot phase ad gain margin, Using Bode plot calculate (a) Phase margin ...

Using Bode plot calculate (a) Phase margin (b) Gain margin (c) Stability of closed loop system. The open transfer function of the system is t=30/(s+2)/(s+3)Using Bode plot calcula

Determine the electric force on each charge, Q Point charges, each of √4πε0...

Q Point charges, each of √4πε0 C, are located at the vertices of an equilateral triangle of side a. Determine the electric force on each charge.

Define sampling below the nyquist rate, Define Sampling below the Nyquist R...

Define Sampling below the Nyquist Rate? A further reduction of the sampling frequency will reason one sample to be taken each period. The Case 3 plot depicts the effect of this

Show effects of saliency and saturation, Q. Show Effects of Saliency and Sa...

Q. Show Effects of Saliency and Saturation? Because of saliency, the reactancemeasured at the terminals of a salient-pole synchronousmachine as opposed to a cylindrical-rotor m

Probability assignment, how probability help in the field of electrical tel...

how probability help in the field of electrical telecommunication engineering?

Explain the operation as a buffer, Q. An interesting application of the SRF...

Q. An interesting application of the SRFF is as a buffer in overcoming contact bounce in mechanical switches. These switches, of the toggle type, may be used to change the logic st

Find the current and voltage at input terminals of the line, Q. A source of...

Q. A source of impedance ¯ Z S = R S = 100  has an open-circuit voltage v S (t) = 12.5 cos ωot and drives a 75- transmission line terminated with a 75- load. Find the current

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