Hi i wrote the code below for a T89C51CC01 atmel's controller.When i tried to build it, it gives the following error message:(Build target 'Target 1' compiling xixi.c... XIXI.C(7): error C231: 'P1': redefinition XIXI.C(8): error C231: 'P3': redefinition Target not created) These errors are caused by the 2 first lines after the include statements(sfr P1 = 0x90; sfr P3 = 0xB0;) Can anyone help me? The code: #include <absacc.h> #include <string.h> #include <stdio.h> #include <REG51CC01.H> sfr P1 = 0x90; sfr P3 = 0xB0; sbit DIPswitch = P1^4; sbit greenLED = P1^5; void main (void) { unsigned char inval; inval = 0; // initial value for inval while (1) { if (DIPswitch == 1) { // check if input P1.4 is high inval = P1 & 0x0F; // read bit 0 .. 3 from P1 greenLED = 0; // set output P1.5 to low } else { // if input P1.4 is low greenLED = 1; // set output P1.5 to high } P3 = (P3 & 0xF0) | inval; // output inval to P3.0 .. P3.3 } }