data transfertwo most fundamental data transfer

Question

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