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

Cmp-arithmetic instruction-microprocessor, CMP: Compare: - This instructio...

CMP: Compare: - This instruction compares the source operand, which can be a register or memory location an immediate data with a destination operand that might be a register or a

Aas-arithmetic instruction-microprocessor, AAS: ASCII Adjust AL After Subt...

AAS: ASCII Adjust AL After Subtraction AAS instruction correct the result in the AL register after subtracting operation of two unpacked ASCII operands. The result is in unpacked

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

DIV subroutine, I need a division subroutine. Asks for two inputs, then dis...

I need a division subroutine. Asks for two inputs, then displays the inputs and shows the answer with a remainder. Mine isnt displaying the inputs correctly.

Write an 8086 assembly program, Project Description: Write an 80x86 asse...

Project Description: Write an 80x86 assembly program that performs the following functions: Reads a set of integers from a file into an array. The data file name is to be

Name-offset-assemblers directive-microprocessor, NAME : Logical Name of...

NAME : Logical Name of a Module: The NAME directive which is used to assign a name to an assembly language program module. The modulecan now be mention to by its declared name.

Register organization of 8086-microprocessor, Register Organization of 8086...

Register Organization of 8086 8086  has  a great  set  of registers  containing  special  purpose and general  purpose  registers.  All the 8086 resisters are 16-bit registers.

Relocate program and data, ) What is the difference between re-locatable pr...

) What is the difference between re-locatable program and re-locatable data?

Al registre, check the al-register for palindromic number

check the al-register for palindromic number

Write program that will generate array of ten random number, 1. Write a pro...

1. Write a program that will generate an array of ten random 32-bit integers, and that will  display on the monitor the numbers followed by either the words " has the fourth bit se

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