单片机小白求教，帮忙看看这个程序哪错了，双字节乘法ORG 0

单片机小白求教，帮忙看看这个程序哪错了，双字节乘法
ORG 0000H
MAIN:CLR C
MOV R2,#24H
MOV R3,#03H
MOV R6,#02H
MOV R7,#02H
MOV A,R3
MOV B,R7
MUL AB
MOV 62H,B
MOV 63H,A
MOV A,R3
MOV B,R6
MUL AB
ADD A,62H
MOV 62H,A
CLR A
ADDC A,B
MOV 61H,A
MOV A,R2
MOV B,R7
MUL AB
ADD A,62H
MOV 62H,A
MOV A,61H
ADDC A,B
MOV 61H,A
CLR A
RLC A
XCH A,R2
MOV B,R6
MUL AB
ADD A,61H
MOV 61H,A
MOV A,60H
ADDC A,B
MOV 60H,A
RET