The LOOP instruction executes the group of instructions a number of times and it uses relative addressing mode. Let us see briefly each LOOP instruction.
Instruction cx programmer code#
CX register must be loaded with the number of iterations to be performed, prior to entering the section of the code terminated by LOOP instructions. The condition is to check the CX register and zero flag (ZF) or can be only to check the CX register. The various LOOP instructions and their functions are listed below.ĭecrements CX by one, if CX ≠ 0, jump to "short-label".ĭecrements CX by one, if CX ≠ 0 and ZF = 1, jump to "short-label".ĭecrements CX by one, if CX ≠ 0 and ZF = 0, jump to "short-label".Īll the above instructions are iteration control instructions and are used to execute a series of instructions repeatedly on the successful satisfaction of the condition.
Basically, the LOOP instructions are short jump instructions on a condition i.e., when the condition satisfies a short jump is taken whose destination or target address is in the range of -128 bytes to +127 bytes from the instruction address after LOOP instruction. The loop instructions cause the microprocessor to execute a series of instructions repeatedly. LOOP Instructions of 8086 Microprocessor : These instructions are called LOOP instructions.
Similarly, the designers of the 8086 microprocessor came up with a group of instructions to perform repeated execution of a series of instructions a specified number of times much easier. In all the programming languages there are some specific structures to express this repeated execution of instructions. Sometimes while executing a program there will be a need for repeated execution of some instructions a specified number of times.
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