Reset Reason: Support for determining the cause of the most recent MCU reset.
Watchdog: Peripheral which resets the chip if software doesn't service it within a configurable amount of time. Used to guard against software hangs.
Async SPI: Allows use of SPI controller mode in the background via interrupts and/or DMA.
True Random Number Generator: Cryptographic-grade True Random Number Generator (TRNG). This is required to implement SSL communications securely unless you provision devices with an entropy seed stored in nonvolatile storage.
Flash IAP: Driver allowing In-Application Programming (IAP) of the MCU flash memory.
μs Ticker: Clock peripheral with at least microsecond resolution that Mbed uses to implement Timer and Ticker.
Low-Precision Ticker: Also known as the Low-Power Ticker, this peripheral keeps time at a low-frequency clock (usually 32kHz) and generates events for the application. Usually it is used to implement low power sleep.
