The STM8S103K3T6C is an 8-bit MCU with an STM8 core running at 16 MHz. It has 8 KB Flash, 1 KB RAM, and 640 bytes EEPROM, operating from 2.95 V to 5.5 V. The 32-LQFP package provides 28 I/O lines.
The 16 MHz clock rate is enough for a 10 ms control loop with sensor polling and a UART transaction; for faster PWM update rates or multiple serial ports running simultaneously, check the instruction-cycle budget against your interrupt latency.
Memory sizing — Flash, RAM, and EEPROM
8 KB of Flash holds a bootloader and main loop. The 1 KB RAM handles buffers and stack. The 640-byte EEPROM stores calibration constants or fault logs.