SWCU195A December 2024 – May 2025 CC2744R7-Q1 , CC2745P10-Q1 , CC2745R10-Q1 , CC2745R7-Q1 , CC2755R10
The RTC is a 67-bit, 2-channel timer running on the LFCLK system clock. The RTC is active in STANDBY and ACTIVE power states. When the device enters the RESET or SHUTDOWN state, the RTC is reset.
Upon asynchronous device resets (for example, reset pin, exit from shutdown, LF clock loss, and so on), the RTC is reset. However, upon internally generated synchronous device resets (for example, WDT, debug reset, system reset request, and so on), the RTC is not reset.
The RTC accumulates time elapsed since reset on each LFCLK. The RTC counter is incremented by LFINC at a rate of 32.768kHz. LFINC indicates the period of LFCLK in μs, with an additional granularity of 16 fractional bits.
The counter can be read from two 32-bit registers. RTC.TIME8U has a range of approximately 9.5 hours with an LSB representing 8 microseconds. RTC.TIME524M has a range of approximately 71.4 years with an LSB representing 524 milliseconds.
There is hardware synchronization between the system timer (SYSTIM) and the RTC so that the multi-channel and higher resolution SYSTIM remain in synchronization with the RTC’s time base.
The RTC has two channels: one compare channel and one capture channel, and is capable of waking the device out of the standby power state. The RTC compare channel is typically used only by system software and only during the standby power state.