89v51rd2 error 127

Where the definitions appear relative to main() is of no consequence.

Where the definitions appear relative to main() is of no consequence.

Not 100% correct.

When the definitions are ones that are required by main(), they should appear prior to main().

"When the definitions are ones that are required by main(), they should appear prior to main()."

The declarations would have to appear prior to main() - not necessarily the the definitions.

However, the OP is getting Linker errors - so this has nothing to do with the source code...

not necessarily the the definitions

Yes, which is precisely why I was careful to start my sentence with "When ...".

You said: "When the definitions are ones that are required by main(), they should appear prior to main()"

That's not true.

The definitions of symbols referenced in main() do not have to appear prior to main() - provided that declarations appear prior to main().

That's not true.

But your first response on the matter indicated a level of uncertainty.

When the definitions are ones that are required by main(), they should appear prior to main().

It's a good thing, then, that there's no way main() can require any definitions, so this means nothing.

It's a good thing, then, that there's no way main() can require any definitions, so this means nothing.

Well spotted. Give yourself a gold star.

I have included all my definations in a header file called mc_ad1.h

//#include <REGX51.H>
#include <REG51F.H>
#include <intrins.h>
//#include <8052.h>
#include "mc_ad1.h"
#include "eeprom.h"
#include "hw_sw_def.h"

//variables for eeprom
unsigned char *read_ptr,*write_ptr;
extern unsigned char rd_buffer;

//variables for serial communication
unsigned char ser_in_arr[5],*rec_ptr;
unsigned char ser_out_arr[12],*tr_ptr;
volatile bit SER_DATA_RDY_F,TR_RDY_F,COMM_OK_F;

volatile unsigned int gptimer;

unsigned char xdata test_no;                                          //1
unsigned int xdata test_current1,test_current2,time1,time2,time3; //2,4,6,8,10

unsigned int xdata tol_limit_low,tol_limit_high;
unsigned int xdata req_count;
unsigned int xdata corr_limit_low,corr_limit_high;
unsigned int xdata dac_count,pulse_count;
unsigned int adc_count;
unsigned int dac_count_limit_low,dac_count_limit_high;
volatile bit OFL_F,POL_F;
unsigned char pol_cntr,ofl_cntr;
volatile bit DAC_SET_F,ADC_READY_F,OUT_DATA_F = 0;
unsigned int adc_count_arr[5];
unsigned char index = 0;
volatile bit CHK_CURRENT_F,NEG_F;
unsigned char dac_out_delay_cnt = 0;


unsigned char state_no,key_state_no;
volatile bit ASK_KEY_F,KEY_HIT_F;
unsigned char key_value;
volatile bit START_F,TEST_MODE_F;

volatile bit VIEW_ONLY_F,DISP_TIME_F;
unsigned char xdata restore_disp_no;
unsigned char set_pointer,blink_ptr;
volatile bit SETT_ERR_F;
unsigned char temp[6];

unsigned int xdata time = 0;
unsigned char xdata time_counter = 0,time_mode = 1;
volatile bit START_TIME_F,NOTRIP_F,TRIP_F,DISP_UPDATE_F,DISP_CURRENT_F,CERR_F;

void main(void)
{
init_timer0();
init_timer1();
init_serport();
read_from_eeprom();
chk_data();
// test_no = 1;
// default_set();
delay_100_ms(2);
init_int0();
init_int1();
key_state_no = INIT;
state_no = INIT_TEST;
reset_dac_out();
disp_scr();
while(1)
        {
        /*if(ADC_READY_F)
            {
            ADC_READY_F = 0;
            adc_read();
        //     current = calc_test_current(adc_count);
            disp_current(adc_count);
            delay_100_ms(5);
                TEST1 = ~TEST1;
            }*/

     if(ASK_KEY_F)
        {
//        P1^5 ^= 0x01;
        ASK_KEY_F = 0;
        ask_disp_key_val();
        }

    if(KEY_HIT_F)
        chk_keys();

    chk_test_over();
    }
//remaining code(called functions below)
}

I have defined all the fuctions ,I am new to keil preeviously using sdcc compiler.I have tried to remove syntactical errors,but can't understand meaning of these errors.