PLL46XX_PDIV_MASK
pdiv = (pll_con0 >> PLL46XX_PDIV_SHIFT) & PLL46XX_PDIV_MASK;
old_pdiv = (pll_con0 >> PLL46XX_PDIV_SHIFT) & PLL46XX_PDIV_MASK;
(PLL46XX_PDIV_MASK << PLL46XX_PDIV_SHIFT) |
(PLL46XX_PDIV_MASK << PLL46XX_PDIV_SHIFT) |