while(1){

          temp_V_os_PWR = Get_V_os_PWR();
            if(count_V_os > 0){
                  count_V_os--;
                   summ_V_os_PWR += temp_V_os_PWR;
            }
            else {
                     summ_V_os_PWR = summ_V_os_PWR / 20;
                      temp_V_os_PWR = (U8) ((U16) summ_V_os_PWR);
                       count_V_os = 20;
                   }
//это в main

//в прерывании:
#pragma vector = ADC_vect
__interrupt void ADC_interrupt(void);

__interrupt void ADC_interrupt(void){
unsigned char  temp_adc_result = 0;
        temp_adc_result = ((unsigned char)(ADCH));
 
        if( temp_adc_result >0xf0) temp_adc_result =0xfc;

switch (gv_adc_state) {
       gv_Vcc_tst = (unsigned char) ( ( (unsigned int)((unsigned char)(temp_adc_result) + (unsigned char)( gv_Vcc_tst)) ) >> 1 );//среднее с предыдущим
             gv_adc_state = V_os_PWR_CONV;
         Start_conv_channel(V_os_PWR_CHANNEL);
      break;

      case V_os_PWR_CONV :

         gv_V_os_PWR = (unsigned char) ( ( (unsigned int)((unsigned char )(temp_adc_result) + (unsigned char)(gv_V_os_PWR)) ) >> 1 );

          gv_adc_state = middleCurrent1_CONV ;
        Start_conv_channel(V_middleCurrent1_CHANNEL);
        break;