DA7218_BYTE_MASK
pll_frac_top = (frac_div >> DA7218_BYTE_SHIFT) & DA7218_BYTE_MASK;
pll_frac_bot = (frac_div) & DA7218_BYTE_MASK;
(rx_mask & DA7218_BYTE_MASK));
((rx_mask >> DA7218_BYTE_SHIFT) & DA7218_BYTE_MASK));