线选法 2222 G A0~A7A8~A12 A0~A7A8~A12 A0~A7A8~A12 DO DT OE WR DON DT OE WR DO D3 OE WR P2.7P2.6P2.5P2.4P2.3P2.2P2.1P2.0A7A6A5A4A3A2A1A0 00000000000000≡C000H 1101111111111111~ DFFFH Ⅱ:1010000000000000=A00OH 1011111111111111~ BFFFH Ⅲ:0110000000000000~0111111111111111=6000H~7FFFH1.线选法 P2.7 P2.6 P2.5 P2.4 P2.3 P2.2 P2.1 P2.0 A7 A6 A5 A4 A3 A2 A1 A0 Ⅰ： 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 =C000H ～1 1 0 1 1 1 1 1 1 1 1 1 1 1 1 1 ～DFFFH Ⅱ： 1 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 =A000H ～1 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 ～BFFFH Ⅲ：0110 0000 0000 0000～0111 1111 1111 1111 =6000H～7FFFH