RTC V2 is an APB4 real-time clock controller with an independent timekeeping clock domain. It provides a 64-bit Unix-epoch counter, 1/256-second resolution, two alarms, a periodic wake timer, smooth digital calibration, interrupts, and a dedicated wake request.
The APB and RTC clocks may be asynchronous. Software submits bounded commands through one-entry Common asynchronous mailboxes; APB transfers never wait for the slow clock. Time reads use an explicit atomic snapshot.
The register ABI is manually encoded in
rtl/rtc_define.svh and
sw/include/rtc_regs.h. Run make register-check
whenever either definition changes.
make doctor
make format-check register-check lint
make test synth formalSee doc/datasheet.md for the programming model and
doc/integration.md for clock, reset, and wake-domain
requirements.