MOV A,R5 ADDC A,R3 MOV R7,A RET
双子节求补程序对R3R2求补：CPL1: MOV CPL ADD MOV MOV CPL ADDC MOV RET
双字节带符号乘法子程序 ：
MULT1: MOV RLC MOV
JNC MOV CPL ADD MOV A,R2 A A,#01H R2,A A,R3 A A,#00H R3,A A,R7 A 21H.0,C POS1
A,R6 A A,#01H R6,A
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MOV A,R7 CPL A ADDC A,#00H MOV R7,A POS1: MOV A,R5 RLC A MOV JNC MOV CPL ADD MOV MOV CPL ADDC MOV POS2: ACALL MOV ANL JC MOV ORL JNC DEC MOV CPL ADD MOV INC MOV 22H.0,C POS2 A,R4 A A,#01H R4,A A,R5 A A,#00H R5,A MULT C,21H.0 C,22H.0 TPL2 C,21H.0 C,22H.0 TPL2 R0 A,@R0 A A,#01H @R0,A R0 A,@R0
45