M8C core at 24 MHz — 4 KB flash budget
The CY8C21223-24SXI is an 8-bit M8C microcontroller from the PSoC®1 CY8C21xxx family, clocked at 24 MHz. The 4 KB flash and 256 x 8 RAM set the firmware and data buffer ceiling — enough for a single control loop with a small state machine, but tight for a protocol stack with multiple buffers. Twelve I/O in a 16-SOIC package (0.154" body, 3.90 mm width) means every pin counts. The 8-channel 8-bit ADC handles slow analog inputs like temperature or potentiometer feedback; the I²C, SPI, and UART/USART blocks cover common sensor and actuator buses without external shift registers.