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

Merge Sort, Write a program to merge two sorted arrays to create a third so...

Write a program to merge two sorted arrays to create a third sorted array containing all values from the two original arrays. Merge is a key component to the mergesort algorithm.

Segment registers-microprocessor, Segment Registers The 8086 addresses ...

Segment Registers The 8086 addresses a segmented memory unlike 8085. The complete 1 megabyte memory, which 8086 is capable to address is divided into 16 logical segments.Thusea

Program that will compute and output tuition cost, Write an assembly progra...

Write an assembly program that will compute and output tuition cost: a. accept keyboard input of the number of credit hours taken b. accept keyboard input of the type of classes 1

16f877 7seg display, do you have experts that know 4 digit 7_Seg dispaly

do you have experts that know 4 digit 7_Seg dispaly

FIRE ALARM PROGRAMMING, PLEASE MAY YOU ASSIST ME WITH SAMPLE CODES FOR PROG...

PLEASE MAY YOU ASSIST ME WITH SAMPLE CODES FOR PROGRAMING A FIRE ALARM MINI PROJECT

External system bus architecture-microprocessor, External System Bus Archit...

External System Bus Architecture : This is a 16 bit processor with 40 pins. It has twenty address pins and out of which sixteen are utilized as data pins. This concept of by us

Intel 8259 interrupt controller-microprocessor, Intel 8259 interrupt contro...

Intel 8259 interrupt controller :  The 8088 processor has only two interrupt control inputs, and interrupt request (INTR) and non mask able interrupt (NMI). NMI are interrupts t

Instructions, Difference between div and idiv

Difference between div and idiv

ISBN CHECK, How do i convert a asci number to numerals?

How do i convert a asci number to numerals?

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