The MCF51AC256 series are members of the ColdFire® family of 32-bit variable-length reduced instruction set (RISC) microcontroller. This document provides an overview of the MCF51AC256 series, focusing on its highly
integrated and diverse feature set.
The MCF51AC256 series are based on the V1 ColdFire core and operates at processor core speeds up to 50.33 MHz. As part of Freescale’s Controller Continuum®, it is an ideal upgrade for designs based on the MC9S08AC128 series of 8-bit microcontrollers.

The MCF51AC256 features the following functional units:
• V1 ColdFire core with background debug module
• Up to 256 KB of flash memory
• Up to 32 KB of static RAM (SRAM)
• Up to two analog comparators (ACMP)
• Analog-to-digital converter (ADC) with up to 24 channels
• Controller-area network (CAN)
• Cyclic redundancy check (CRC)
• Inter-integrated circuit (IIC)
• Keyboard interrupt (KBI)
• Multipurpose clock generator (MCG)
• Rapid general-purpose input/output (RGPIO)
• Two serial communications interfaces (SCI)
• Up to two serial peripheral interfaces (SPI)
• Two flexible timer modules (FTM)
• Timer pulse-width modulator (TPM)