1.MOV A,45HANL A,#0FHORL A,#0FHMOV 45H,A2.MOV DPTR,#2000HMOVX A,@DPTRMOV 20H,A
1.MOV 45H,#0FH2.MOV DPTR,#2000HCLR AMOVC A,@A+DPTRMOV 20H,A