The MC9S12D is a 16-bit MCU composed of standard on-chip peripherals, including:
System resource mapping, clock generation, interrupt control and bus interfacing are managed by the System Integration Module (SIM).
The MC9S12D has full 16-bit data paths throughout. However, the external bus can operate in an 8-bit narrow mode so single 8-bit wide memory can be interfaced for lower cost systems.
A PLL circuit allows power consumption and performance to be adjusted.