The FCS(Frame Check Sum)-16 generator polynomial: x**0 + x**5 + x**12 + x**16.

FCS.c

#define P 0x8408
main()
{
register unsigned int b, v;
register int i;
printf("typedef unsigned short u16;\n");
printf("static u16 fcstab[256] = {");
for (b = 0; ; )
{
if (b % 8 == 0)
printf("\n");
v = b;
for (i = 8; i--; )
v = v & 1 ? (v >> 1) ^ P : v >> 1;
printf("\t0x%04x", v & 0xFFFF);
if (++b == 256)
break;
printf(",");
}
printf("\n};\n");
}