The STM32G031x4/x6/x8 mainstream microcontrollers are based on a high-performance Arm Cortex-M0+ 32-bit RISC core operating at up to 64 MHz frequency. Offering a high level of integration, they are suitable for a wide range of applications in consumer, industrial, and appliance domains and ready for the Internet of Things (IoT) solutions. The devices incorporate a memory protection unit (MPU), high-speed embedded memories (8 Kbytes of SRAM and up to 64 Kbytes of Flash program memory with reading protection, write protection, proprietary code protection, and securable area), DMA, an extensive range

of system functions, enhanced I/Os, and peripherals. The devices offer standard communication interfaces (two I2Cs, two SPIs / one I2S, and two USARTs), one 12-bit ADC (2.5 MSPs) with up to 19 channels, an internal voltage reference buffer, a low-power RTC, an advanced control PWM timer running at up to double the CPU frequency, four general-purpose 16-bit timers, a 32-bit general-purpose timer, two low-power 16-bit timers, two watchdog timers, and a SysTick timer.

Note: For more info Refer to datasheet

Features:  

1. A simple architecture, easy to learn and program
2. Ultra-low-power, energy-efficient operation
3. Excellent code density
4. Deterministic, high-performance interrupt handling
5. Upward compatibility with Cortex-M processor family
6. Platform security robustness, with integrated Memory Protection Unit (MPU)

Specifications: 

1. Proceosser: Arm 32-bit Cortex-M0+ CPU
2. Frequency: 64 MHz
3. Operating Temperature: -40°C to 85°C/105°C/125°C
4. Voltage range: 1.7 V to 3.6 V
5. 32 kHz crystal oscillator with calibration