Information

MPC8308 PowerQUICC II Pro Processor Reference Manual, Rev. 1
Freescale Semiconductor 21-1
Chapter 21
General Purpose I/O (GPIO)
21.1 Introduction
This chapter describes the general-purpose I/O module, including pin descriptions, register settings, and
interrupt capabilities. Figure 21-1 shows the block diagram of the GPIO module.
Figure 21-1. GPIO Module Block Diagram
21.1.1 Overview
The GPIO module supports 24 general-purpose I/O ports. Each port can be configured as an input or as an
output. If a port is configured as an input, it can optionally generate an interrupt on detection of a change.
If a port is configured as an output, it can be individually configured as an open-drain or a fully active
output.
21.1.2 Features
The GPIO unit implements the following features:
• 24 input/output ports
• Some ports have dedicated processor signals. Others are multiplexed together with other functional
signals. See Chapter 2, “Signal Descriptions.”
• All signals are configured as inputs when the device comes out of reset and also when HRESET
is
asserted.
Register
Interface
GPDAT
Register
To /Fr om
Peripheral Bus
GPDIR/
GPODR
Registers
GPIER/
GPIMR/
GPICR
Registers
gpio_int
GPIO[0:23]