Chapter 26 general purpose i/o module, 1 introduction, Chapter 26 – Motorola ColdFire MCF5281 User Manual
Page 501: General purpose i/o module, 1 introduction -1, The appropriate pins (refer to, Chapter 26, “general purpose i/o module

Freescale Semiconductor
26-1
Chapter 26
General Purpose I/O Module
26.1
Introduction
Many of the pins associated with the external interface may be used for several different functions. Their
primary function is to provide an external memory interface to access off-chip resources. When not used
for their primary function, many of the pins may be used as general-purpose digital I/O pins. In some cases,
the pin function is set by the operating mode, and the alternate pin functions are not supported.
The digital I/O pins are grouped into 8-bit ports. Some ports do not use all eight bits. Each port has registers
that configure, monitor, and control the port pins.
and
are block diagrams of the
ports for the MCF521x and MCF528x.
MCF5282 and MCF5216 ColdFire Microcontroller User’s Manual, Rev. 3