Core

32-bit Arm® Cortex®-M0+ processor core
Up to 40 MHz operating frequency
Single-cycle multiplication
Integrated Nested Vectored Interrupt Controller (NVIC)
24-bit SysTick timer

I/O Ports — GPIO

Up to 52 GPIOs
Port A, B, C, D are mapped as 16 external interrupts – EXTI
Almost all I/O pins have a configurable output driving current

Power Management — PWRCU

Single VDD power supply: 2.0 V to 3.6 V
Integrated 1.5 V LDO regulator for CPU core, peripherals and memories power supply
VDD power supply for RTC
Two power domains: VDD , 1.5 V
Four power saving modes: Sleep, Deep-Sleep1, Deep-Sleep2, Power-Down

Analog to Digital Converter — ADC

12-bit SAR ADC engine
Up to 1 Msps conversion rate
Up to 12 external analog input channels

Watchdog Timer — WDT

12-bit down counter with 3-bit prescaler
Reset event for the system
Programmable watchdog timer window function
Register write protection function

Universal Asynchronous Receiver Transmitter – UART

Asynchronous serial communication operating baud-rate up to (fPCLK/16) MHz
Full duplex communication
Fully programmable serial communication characteristics including:
– Word length: 7, 8 or 9-bit character
– Parity: Even, odd or no-parity bit generation and detection
– Stop bit: 1 or 2 stop bit generation
– Bit order: LSB-first or MSB-first transfer
Error detection: Parity, overrun and frame error