AR_RTC_DERIVED_CLK
REG_WRITE(ah, AR_RTC_DERIVED_CLK(ah), 0x17c << 1);
REG_WRITE(ah, AR_RTC_DERIVED_CLK(ah), 0x261 << 1);
REG_RMW_FIELD(ah, AR_RTC_DERIVED_CLK(ah),
(void)REG_READ(ah, AR_RTC_DERIVED_CLK(ah));