单片机键盘中断的Proteus仿真

//注：去掉列线上拉，显示正常。 // 加上列线上拉，近乎死机。 #include"reg52.h" #define uchar unsigned char #define uint unsigned int #define L1 (P2|0xFE) #define L2 (P2|0xFD) #define L3 (P2|0xFB) #define L4 (P2|0xF7) uchar key_value=16; uchar code SMG[]={0xC0,0xF9,0xA4,0xB0,0x99,0x92,0x82,0xF8,0x80,0x90, 0x88,0x83,0xC6,0xA1,0x86,0x8E,0xBF};//0~F显示码。 // A uchar code K_number[]={1,2,3,10,4,5,6,11,7,8,9,12,14,0,15,13};//键号。 // 0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15 //键值。 uchar keyscan() { static uchar temp; // 必须将temp(返回参数)定义为静态。 uchar count=0; P2=0xEF; if(L1!=0xff) temp=count; count++; if(L2!=0xff) temp=count; count++; if(L3!=0xff) temp=count; count++; if(L4!=0xff) temp=count; count++; P2=0xDF; if(L1!=0xff) temp=count; count++; if(L2!=0xff) temp=count; count++; if(L3!=0xff) temp=count; count++; if(L4!=0xff) temp=count; count++; P2=0xBF; if(L1!=0xff) temp=count; count++; if(L2!=0xff) temp=count; count++; if(L3!=0xff) temp=count; count++; if(L4!=0xff) temp=count; count++; P2=0x7F; if(L1!=0xff) temp=count; count++; if(L2!=0xff) temp=count; count++; if(L3!=0xff) temp=count; count++; if(L4!=0xff) temp=count; count++; return temp; } //================================================================================== void main() { uchar key_value=16; EA=1; EX0=1; IT0=0; //低电平中断触发。 P2=0x0F;//(这条语句十分重要)。 P0=SMG[key_value]; while(1); } //================================================================================== void KeyBoard_isr(void)interrupt 0 using 1 { EX0=0; key_value=keyscan();// 读取键值。 P0=SMG[K_number[key_value]]; //根据键值查键号，根据键号查键码。 P2=0x0F;//(这条语句也十分重要)。 EX0=1; }