TDC_RES_MULTIPLIER
temp1 = div64_u64(((4 * TDC_RES_MULTIPLIER) + temp0) * 500, temp0 * refclk_khz);
temp3 = div64_u64(((8 * TDC_RES_MULTIPLIER) + temp2), temp2);
feedfwd_gain = (m2div_frac > 0) ? div64_u64(m1div * TDC_RES_MULTIPLIER, temp0) : 0;