Data Transfer

Two most fundamental data transfer instructions in 8086 microprocessor are XCHG and MOV. Let's give illustrations of the use of these instructions.

Program 1: This program displays the difference of XCHG and MOV instructions:

DATA SEGMENT

                                    VAL    DB      5678H                         ; initialize variable VAL

DATA ENDS

CODE SEGMENT

                                    ASSUME        CS:      CODE, DS: DATA

MAINP:                      MOV               AX, 1234H                 ; AH=12 & AL=34

                                    XCHG            AH, AL                       ; AH=34 & AL=12

                                    MOV               AX, 1234H                 ; AH=12 & AL=34

                                    MOV               BX, VAL                    ; BH=56 & BL=78

                                    XCHG            AX, BX                      ; AX=5678 & BX=1234

                                    XCHG            AH, BL                       ;AH=34,AL=78,BH=12,&BL=56

                                    MOV               AX, 4C00H                ; Halt using INT 21h

                                    INT                 21H

CODE ENDS

END MAINP