Timers do not work

Timers do not work in comparison mode, when setting directly from registers. The interruption does not happen, for the arduino Mega 2560

Hi.

Can you share the code that is not working?

If not, can you tell which values are you using for those registers?

//this is the code for arduino mega, setting the timer in comparison mode
//In the 4.13 of simulIde versión the code works good

/*program that turns a led on and off at 350 ms intervals
using timer 1 in CTC (A) mode or comparison mode*/


#define LED 13

void config_timer(void);

void setup() {
// put your setup code here, to run once:
pinMode(LED,OUTPUT);
config_timer();
}

void loop() {
// put your main code here, to run repeatedly:

}

ISR(TIMER1_COMPA_vect) //Interrupt Service Routine
{
TCNT1=0;
digitalWrite(LED,digitalRead(LED)^1);
}

void config_timer(void){
TCCR1A = TCCR1B = 0;//ELIMINAR CUALQUIE CONF PREVIA DEL TIMER
TCNT1 = 0;//Borro cualquier conteo o valor previo

OCR1A = 21875;// SE COMPARA el timer 1 CONTRA 21875 CONTEOS...con el fin de obtener 350 ms
TCCR1B |= (1 << WGM12); //se configuro el timer 1 en modo de comparación CTC..
TCCR1B |= (1<