8251 programmable/communication interface-microprocessor, Assembly Language

Assignment Help:

8251 Programmable/Communication Interface

As an instance of a serial interface device let us suppose Intel's 8251 A programmable communication interfaces. The 8251A is diagrammed in given figure. It is capable of being programmed for synchronous / asynchronous communication.  The data that is in buffer and data-out buffer registers share the similar port address. For input, the serial bit stream is arriving on the R x D pin is shifted into the receiver shift register and then the data bits are transferred to the data-in buffer register, where they might be input by the CPU. On the other hand on output the data bits put in the data-out buffer register by the CPU are transferred to the transmitter shift register and, along with the essential synchronization bits, are shifted out through the T x D pin. Among other things the contents of the mode register, which are begin by the executing program, determine whether the 8251A is in synchronous mode or asynchronous mode and the format of the characters being received and transmitted. The control register, which is set by the program, controls the operation of the interface, and the status register makes sure information available to the executing program. Obviously, the sync character registers are for storing the sync characters required for synchronous communication.

1142_8251.jpg

Even though all 7 of the registers on the left side of Figure 4.7 may be accessed by the processor, the 8251A is associated with only 2 port addresses. The C/D pin is linked to the address line AO and AO differentiates the 2 port addresses. The 8251A internally interprets the C/D, RD, and WR signals as follows:

1611_8251 signals.jpg


Related Discussions:- 8251 programmable/communication interface-microprocessor

Program, write a program assembly language for adding two 3*3 matrix

write a program assembly language for adding two 3*3 matrix

Programming with an assembler-microprocessor, Programming with an assembler...

Programming with an assembler The procedure of hand-coding 8086 programs is somewhat tiresome; hence generally a programmer may find it hard to get a correct listing of the mac

Embeded programming, i want to develop traffic light system so which kind o...

i want to develop traffic light system so which kind of software is needed to develop this project?

Sequence of interrupts, As an instance of the normal priority mode, imagine...

As an instance of the normal priority mode, imagine that initially AEOI is equal to 0 and all the ISR and IMR bits are clear. Also consider that, as shown in given figure, requests

8086, Write a program to mask bits D3D2D1D0 and to set bits D5D4 and to inv...

Write a program to mask bits D3D2D1D0 and to set bits D5D4 and to invert bits D7D6 of ax register

Write policy-microprocessor, Write Policy A write policy determines how...

Write Policy A write policy determines how the cache deals with a write cycle. The 2 common write policies areWrite-Throughand Write-Back. In Write-Back policy, the cache behav

Efficient assembly language program, (1) Write a program that will: (a) dis...

(1) Write a program that will: (a) display "Enter Your Name:" (b) convert the entered name to Capital letters (if small), If any other character is entered, the program wil

Formulate the linear programming model , Print Media Advertising (PMA) has ...

Print Media Advertising (PMA) has been providing a contract to market Buzz Cola via newspaper ads in a main southern newspaper. Full-page ads in the weekday editions (Monday throug

Aaa-arithmetic instruction-microprocessor, AAA: ASCII Adjust after Additio...

AAA: ASCII Adjust after Addition operation the AAA instruction is executed after an ADD instruction that adds 2 ASCII coded operands to give a byte of outcome in the AL. The AAA i

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