System control determines the overall operation of the CC27xx device. System control provides information about the devices, controls power-saving features, controls the clocking of the devices and individual peripherals, and handles reset detection and reporting.
- Power Control:
- On-chip fixed DC/DC converter and Global low drop-out (GLDO) voltage regulators
- Handles the power-up sequencing, power-down sequencing, and control for the core digital-logic and analog circuits
- Low-power options for on-chip modules:
- Software controls shutdown of individual peripherals and memory.
- SRAM is retained in all power modes except shutdown.
- Configurable wake up from standby by RTC or any IOC interrupt
- Voltage supervision circuitry
- Multiple clock sources for microcontroller system clock:
- High Frequency Clock:
- Clock doubler: Provides 96MHz clock to core digital functions
- RC oscillator (HFOSC): on-chip 96MHz RC oscillator
- External oscillator (HFXT): external 48MHz crystal oscillator connected across the X48P input and X48N output pins.
- Radio operation requires the external oscillator.
- Auxiliary Frequency Oscillator (AFOSC): The 80/90.3168/98.304MHz AFOSC is used as the high-frequency clock for generating needed frequencies to support for CAN-FD and audio I2S operations. The AFOSC tracks the HFOSC, which in turn, tracks its accuracy against the external 48MHz crystal (HFXT). AFOSC can generate 79, 80, 86, 90.3168, and 98.304MHz clock frequencies with a 10ppb tracking accuracy from HFOSC.
- Low Frequency Clock:
- RC oscillator (LFOSC): on-chip 32kHz RC oscillator.
- External oscillator (LFXT): external 32.768kHz crystal oscillator connected across the X32P input and X32N output pins
- Designed for accurate RTC operation or synchronous network timing
- Used during power-saving modes and for RTC