R1*R2R3
ORG 0000H
LJMP MAIN
ORG 0030H
MAIN: MOV R1,#01H
MOV R2,#02H
MOV R3,#04H
MOV A,R3
MOV B,R1
MUL AB
MOV R6,A
MOV R5,B
MOV A,R2
MOV B,R1
MUL AB
MOV R4,B
ADD A,R5
MOV R5,A
MOV A,R4
ADDC A,#00H
MOV R4,A
SJMP $
END
R1R2R3R4
ORG 0000H
LJMP MAIN
ORG 0030H
MAIN: MOV R1,#01H
MOV R2,#01H
MOV R3,#01H
MOV R4,#00H
LCALL MULL
MOV R5,30H
MOV R6,31H
MOV R7,32H
MOV A,R1
MOV R2,A
LCALL MULL
CLR C
MOV A,32H
ADD A,R6
MOV R6,A
MOV A,R5
ADDC A,31H
MOV R5,A
MOV A,#00H
ADDC A,30H
MOV R4,A
SJMP $
MULL: MOV A,R4
MOV B,R2
MUL AB
MOV 32H,A
MOV 31H,B
MOV A,R3
MOV B,R2
MUL AB
MOV 30H,B
ADD A,31H
MOV 31H,A
MOV A,30H
ADDC A,#00H
MOV 30H,A
RET
END