+ // Synchronize the external toggle into the clint
+ val rtc_sync = ShiftRegister(outer.aon.module.io.rtc.asUInt.toBool, 3)
+ val rtc_last = Reg(init = Bool(false), next=rtc_sync)
+ val rtc_tick = Reg(init = Bool(false), next=(rtc_sync & (~rtc_last)))
+
+ outer.clint.module.io.rtcTick := rtc_tick