SWCU195A December 2024 – May 2025 CC2744R7-Q1 , CC2745P10-Q1 , CC2745R10-Q1 , CC2745R7-Q1 , CC2755R10
We can choose the LF clock between the following four options using the MMR CKMD.LFCLKSEL.MAIN :
No LF clock
LFOSC
LFXT
External LF clock from DIO
The chosen LF clock is delayed in Analog. The delay is configurable through the MMR CKMD.TRIM1.LFDLY.
The delayed LF clock is used to increment the RTC and also as a system clock in standby.
When the selected low-frequency clock is not running, the HFOSC clock is used to generate a Fake LF clock. Thus, the low-frequency clock can be categorized into :
Real LF clock (Which can be from LFOSC or LFXT, or an external LF clock from DIO)
Fake LF clock (Which is generated using HFOSC, which can be tracked or untracked)