Description: CPU kernel: ARM Cortex-M23 CPU Max Main frequency: 72 MHz Operating voltage Range: 1.8V~3.6V Internal oscillator: External clock frequency range: 4 MHz ~ 32 MHz Program FLASH Capacity: 64KB RAM Total capacity: 8KB GPIO Port number: 23 ADC (cells / channel / digits): 1@x10ch / 12bit (E) PWM (unit