*** WARNING L1: UNRESOLVED EXTERNAL SYMBOL
SYMBOL: ?C_START
MODULE: STARTUP.obj (?C_STARTUP)
*** WARNING L2: REFERENCE MADE TO UNRESOLVED EXTERNAL
SYMBOL: ?C_START
MODULE: STARTUP.obj (?C_STARTUP)
#include <reg51.h>
sbit RA0 = P2^0;
sbit RA1 = P2^1;
sbit RA2 = P2^2;
sbit RA3 = P2^3;
sbit RA4 = P2^4;
sbit RA5 = P2^5;
sbit RC0 = P1^0;
sbit RC1 = P1^1;
int A;
//=====================
main()
{
RA0=1;
RA1=1;
RA2=1;
RA3=1;
RA4=1;
RA5=1;
RC0=0;
RC1=0;
while(1){ if(RA0==0 )
{ A=1; }
if(RA1==0 )
{ A=2; }
if(RA2==0 )
{ A=3; }
if( RA3==1 && RA4==1 && RA5==1&&A==1)
{RC0=1;
RC1=0;
}
if( RA3==1 && RA4==0 && RA5==1&&A==1)
{RC0=0;
RC1=1;
}
if(A==1 && RA3==0)
{RC0=0;
RC1=0;
}
if( RA4==1 && RA3==0 && RA5==1&&A==2)
{RC0=0;
RC1=1;
}
if(RA4==1 && RA4==1 && RA5==0&&A==2)
{RC0=1;
RC1=0;
}
if(RA1==1 && RA4==0)
{RC0=0;
RC1=0;
}
if( RA3==1 && RA4==0 && RA5==1&&A==3)
{RC0=0;
RC1=1;
}
if(RA2==1 && RA5==0)
{RC0=0;
RC1=0;
}
}
}
为什么会出现2个警告程式哪出错了??