create a C program to print Fibonacci series upto a specified number N using while loop.

Sure, here is a simple C program that prints the Fibonacci series up to a specified number N using a while loop:

#include <stdio.h>

int main() {
    int N, first = 0, second = 1, next;

    printf("Enter the number of terms\n");
    scanf("%d", &N);

    printf("First %d terms of Fibonacci series are:\n", N);

    int i = 0;
    while (i < N) {
        if (i <= 1)
            next = i;
        else {
            next = first + second;
            first = second;
            second = next;
        }
        printf("%d\n", next);
        i++;
    }

    return 0;
}

This program first initializes the first two terms of the Fibonacci series, 0 and 1. It then enters a while loop, which continues until it has printed N terms. In each iteration of the loop, it calculates the next term by adding the previous two terms, and then updates the two previous terms to be the second and the new term, respectively. It then prints the new term.