SWRS272D April 2023 – July 2024 CC2340R2 , CC2340R5
PRODMIX
The CC2340R device has the following internal system clocks.
The 48MHz HFCLK is used as the main system (MCU and peripherals) clock. This is driven by the internal 48MHz RC Oscillator (HFOSC), which can track its accuracy against an external 48MHz crystal (HFXT). Radio operation requires an external 48MHz crystal.
The 32.768kHz LFCLK is used as the internal low-frequency system clock. It is used for the RTC, the watchdog timer (if enabled in standby power mode), and to synchronize the radio timer before or after Standby power mode. LFCLK can be driven by the internal 32.8kHz RC Oscillator (LFOSC), a 32.768kHz watch-type crystal, or clock input in LFXT bypass mode. When using a crystal or the internal RC oscillator, the device can output the 32kHz LFCLK signal to other devices, thereby reducing the overall system cost.