Core

32-bit Arm® Cortex®-M0+ processor core
Up to 60 MHz operating frequency
Single-cycle multiplication
Integrated Nested Vectored Interrupt Controller (NVIC)
24-bit SysTick timer

I/O Ports — GPIO

Up to 42 GPIOs
Port A, B, C, F 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: 1.65 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

Real Time Clock — RTC

24-bit up-counter with a programmable prescaler
Alarm function
Interrupt and Wake-up event

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

Serial Peripheral Interface — SPI

Supports both master and slave mode
Frequency of up to (fPCLK/2) MHz for the master mode and (fPCLK/3) MHz for the slave mode
FIFO Depth: 8 levels
Multi-master and multi-slave operation