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

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

Cmps-string manipulation instruction-microprocessor, CMPS : Compare String...

CMPS : Compare String Byte or String Word:-The CMPS instruction may be utilized to compare two strings of Words or byte. The length of the string ought to be stored in the CX. If

Arithmetic instruction-microprocessor , Arithmetic Instruction :           ...

Arithmetic Instruction :               These instructions are usually perform the arithmetic operations, like subtraction ,multiplication, addition, and division along with th

8086 assembly language, write and run a programme using 8086 assembly langu...

write and run a programme using 8086 assembly language that interchange the lower four bits of AL registered with upper four bits.

Code, How to print strings in Right Triangle form?

How to print strings in Right Triangle form?

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

Memory interface-microprocessor, Memory Interface              ...

Memory Interface                                                                  Figure: Memory Modulation design The memory of a computer contain of number of memo

PIC MCU, CAN U GIVE BRIEF THEORY

CAN U GIVE BRIEF THEORY

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