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

Copy a string backwards, I can get it to copy the string but can''t get it ...

I can get it to copy the string but can''t get it to reverse it.

Nonrecursive Factorial, Write a nonrecursive version of the Factorial proce...

Write a nonrecursive version of the Factorial procedure (Section 8.3.2) that uses a loop. (A VideoNote for this exercise is posted on the Web site.) Write a short program that inte

Write an assembly program to find out largest number, Program :  Write an...

Program :  Write an assembly program to find out the largest number from a given unordered array of 8-bit numbers that stored in the locations starting from a known address. S

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

Xor-logical instruction-microprocessor, XOR: Logical Exclusive OR: The XOR...

XOR: Logical Exclusive OR: The XOR operation is again carried out in a similar way to the AND and OR operation. The constraint over operands are also similar. The XOR operation pr

PIC MCU, CAN U GIVE BRIEF THEORY

CAN U GIVE BRIEF THEORY

Counting Array Values(Programming exercises), Write an application that doe...

Write an application that does the following:(1) fill an array with 50 random integers; (2) loop through the array, displaying each value, and count the number of negative values;

Imul-arithmetic instruction-microprocessor, IMUL: Signed Multiplication: T...

IMUL: Signed Multiplication: This instruction multiplies a signed byte by a signed bit in source operand e in the register AL or signed word in source operand by signed word in th

Program which allows the user to select from menu, Write a 32-bit program w...

Write a 32-bit program which when run, allows the user to select from a menu: (1)    Enter a Binary Number (2)    Enter a Decimal Number (3)    Enter a Hexadecimal Number

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