can i know what is the ' i ' inside this coding
if i need to define it , how?
Because i put it inside to another coding , is need to define the ' i '

//Fir.c
#include "bs2700.cof" //coefficient file BS @ 2700Hz
int yn = 0; //initialize filter's output
short dly[N]; //delay samples

interrupt void c_int11() //ISR
{
short i;

dly[0] = input_sample(); //new input @ beginning of buffer
yn = 0; //initialize filter's output
for (i = 0; i< N; i++)
yn += (h * dly); //y(n) += h(i)* x(n-i)
for (i = N-1; i > 0; i--) //starting @ end of buffer
dly = dly[i-1]; //update delays with data move

output_sample(yn >> 15); //scale output filter
return;
}

anyone know it...

 

it is defined:

short i;

and it is used as loop counter

for (i = 0; i< N; i++)
yn += (h * dly); //y(n) += h(i)* x(n-i)

and

for (i = N-1; i > 0; i--) //starting @ end of buffer
dly = dly[i-1]; //update delays with data move