DPLL_PWRDN
if ((dpll & DPLL_PWRDN) == 0) {
REG_WRITE(DPLL_CTRL, dpll | (DPLL_PWRDN | DPLL_RESET));
dpll &= ~(DPLL_PWRDN | DPLL_RESET);
if ((temp & DPLL_PWRDN) == 0) {
REG_WRITE(DPLL_CTRL, temp | (DPLL_PWRDN | DPLL_RESET));
if ((temp & DPLL_PWRDN) != 0) {
REG_WRITE(DPLL_CTRL, temp & ~(DPLL_PWRDN | DPLL_RESET));