sbit P2^0 =key0;

sbit P2^1 =key1;

sbit P2^2 =key2;

sbit P2^3 =key3;

sbit P2^4 =key4;

sbit P2^5 =key5;

sbit P2^6 =key6;

sbit P2^7 =key7;

sbit P0^0 =led0;

sbit P0^1 =led1;

sbit P0^2 =led2;

sbit P0^3 =led3;

sbit P0^4 =led4;

sbit P0^5 =led5;

sbit P0^6 =led6;

sbit P0^7 =led7;

假設按鍵按下為低電平，點亮LED用高電平，則示意程式碼如下

if（key0 == 0)

led0 = 1;

if（key1 == 0)

led1 = 1;

if（key2 == 0)

led2 = 1;

if（key3 == 0)

led3 = 1;

...........

............

if（key7 == 0)

led7 = 1;