Conditional branch instruction-microprocessor, Assembly Language

Conditional branch Instruction

When these type of instructions are executed, they transfer control of execution to the address mention relatively in the instruction, provided the condition implicit in the op code is satisfied, or else, the execution continues in sequence. Here, the conditions mean the status of condition code flags. These types of instructions remain unaffected from any flag. The address has to be mention in the instruction relatively in the terms of displacement which ought to be lie within range -80H to 7FH (or -128 to 127) bytes from the address of the branch instruction. In other terms, only short jumps may be implemented by using the conditional branch instructions.  A label can represent the displacement, if it lies within the above mention range. The different 8086/8088 conditional branch instructions and their operations are listed in the following Table.

2183_conditional branch instruction.jpg


Last four instructions are utilized in the case of on signed binary number and decisions based operations, while all the remaining instructions may be utilized for unsigned binary operations.  The  terms  below  and  above  are usually  utilized for unsigned  numbers, while the terms greater and less are utilized for signed  numbers. A conditional jump instruction that does not examine status flags for condition testing, is following:

JCXZ 'Label' Transfer execution control to address 'Label', if register CX is equal to zero.

The conditional LOOP instructions are shown in following table along with their meanings. These instructions can be used for implement structures like REPEAT_UNTIL, DO_WHILE etc.

1192_cli.jpg

                                         Figure: Conditional loop instructions

The ideas regarding all these instructions will be clearer with the programming practice. This topic is intended at introducing these instructions to the readers. Of course, the examples are quoted wherever possible but the LOOP and the JUMP instructions need a sequence of instructions for explanations and will be emphasized.

 

 

Posted Date: 10/12/2012 5:14:41 AM | Location : United States







Related Discussions:- Conditional branch instruction-microprocessor, Assignment Help, Ask Question on Conditional branch instruction-microprocessor, Get Answer, Expert's Help, Conditional branch instruction-microprocessor Discussions

Write discussion on Conditional branch instruction-microprocessor
Your posts are moderated
Related Questions
DMA controller :     Steps include in transferring a block of data from I/O devices (for example a disk) to memory: 1. CPU sends a signal to initiate disk transfe

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

given a sentence, find the number of times a particular character or word appear. the sentence is to be entered by the user

i have trying to do the homework but there is a mistake. (Counting positive and negative numbers and computing the average of numbers) write a program that reads an unspecified nu

1. Start your program at address $8500. To do this you need to inform the assembler, through the EQU and ORG assembler directives, that you want your program to start at $8500. Thi

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

A/D conversion: Basic tasks: (a) Write a program that will read and display the analog voltage on pin PE7 approximately once every second. (b) Write a program that will read and d

8088  Timing System Diagram The 8088 address/data  bus is divided  in 3 parts (a) the lower 8 address/data  bits, (b) the middle 8 address bits, and (c) the upper 4 status/

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