The S12C is part of Freescale's 48/52/80 pin flash-based MCU family, which delivers the power and flexibility of the 16-bit core to a wide range of cost and space sensitive general-purpose industrial and automotive network applications.

Composed of standard on-chip peripherals including a 16-bit central processing unit (HCS12 CPU), 128 KB of flash EEPROM, 4 KB of RAM, an asynchronous serial communications interface (SCI), a serial peripheral interface (SPI), an 8-channel 16-bit timer module (TIM), a 6-channel 8-bit pulse width modulator (PWM), an 8-channel, 10-bit analog-to-digital converter (ADC) and a CAN 2.0 A, B software compatible module (MSCAN12).

An on-chip bandgap-based voltage regulator (Vreg) generates the internal digital supply voltage (VDD) for a 2.97-volt to 5.5-volt external supply range. The MC9S12C128 has full 16-bit data paths throughout. The inclusion of a phase-lock look (PLL) circuit allows power consumption and performance to be adjusted to suit operational requirements. A total of 50 I/O port pins and two input pins are available in the 80-pin package version. Up to 12 I/O port bits are available with wake-up capability from stop or wait mode.