EMU8086 PROGRAM TO ADD TWO NUMBERS CODE

The 6 th instruction SUB, AX subtracts AX from the data stored at memory location DS:SI and stores the difference at the same memory address. In the next instruction, SI is loaded with 0700H. The SUB AX, BX instruction subtracts BX from AX and store the difference in AX which is:ДЄX = 9CA вЂ“ 66F = 35B.

EMU8086 PROGRAM TO ADD TWO NUMBERS CODE

The subtraction instruction supports the following operands: Source Destination Example Register Register SUB CH, AL Register Immediate SUB AX, 16H Register Memory Address SUB, AX SUB 19, CX Memory Address Register SUB AL, 10 Example Assembly Code ORG 100h If one operand is in a byte and the other in words then insert two zeroвЂ™s at the start of bytes. Just like ADD instruction, both operands should be either in bytes or words. Subtract the data in the source operand from the data of destination operand and then store the result back to the destination operand. Subtraction instruction takes two operands. DAS Subtraction Instruction without Carry.The first four bits of AL are also 0.ДЁ086 microprocessor supports the following subtraction Instructions: In this case, the lower nibble of AL is 3 which is less than 9.

Add 1 to contents of AH Example Assembly Code ORG 100h.

If lower nibble of AL is between 0 to 9:Дў. It checks the AL register and then take following actions:ДЎ. The AAA instruction does not require any operand and operates on the AL register thatвЂ™s why the final sum of two ASCII codes should be in the AL register. It makes sure whether the final result stored is in the form of unpacked BCD or not. The AAA (Adjust after addition) instruction allows the addition operation without masking off the вЂњ3вЂќ in the upper nibble of each digit. Before the addition, you need to mask upper nibble (3) from the code. Suppose you want to add two decimal digits represented in ASCII code. Now when the next ADC instruction executes, it will generate sum of data from memory location 07154H, data from AL register and carry flag bit and stores the result in AL.ДЁ086 AAA (Adjust after addition) Instruction The value 72H goes to AL register and the overflow bit produced sets carry flag to 1. The instruction ADC AL, BH sets AL to 7D + F5= 172. Example Assembly Code ORG 100hДЄDC AL, BH Store the sum of AL and BH in AL The only difference is that ADC instruction also adds the carry flag bit to the sum of two operands. The ADC and ADD instruction perform the same operation of addition. Example Assembly Code ORG 100hДЄDD AL, BH Store the sum of AL and BX in ALДЄDD, CX Store sum of CX data and data at memory address DS:0154 into the same memory addressДЄDD AH,BH Store sum of AH and BH into BH The ADD instruction can affect AF, CF, OF, PF, SF, ZF flags depending upon the result. If the sum of two operands exceeds the size of destination operand, then it would set the carry flag to 1. It supports following operands: Source Destination Example Register Register ADD AX, BX Register Immediate ADD CL, 2DH Register Memory Address ADD, AL ADD +23, DX Memory Address Register ADD CL,

words or bytes otherwise assembler will generate an error. Both operands should be of same type i.e.

This instruction adds the data of destination and source operand and stores the result in destination. Now lets discuss the details of Addition instructions with assembly code examples.

8086 DAS Instruction 8086 Integer Addition InstructionsДЁ086 microprocessor supports following types of addition instructions.

DAA (Decimal Adjust Accumulator) Instruction.

8086 AAA (Adjust after addition) Instruction.

Emu8086 program to add two numbers