Motorola DSP56012 7.1 INTRODUCTION, 7.2 GPIO PROGRAMMING MODEL, 7.3 GPIO REGISTER (GPIOR)

GPIO
Introduction
MOTOROLA DSP56012 User’s Manual 7-3
7.1 INTRODUCTION
The General Purpose Input/Output (GPIO) pins are used for control and handshake
functions between the DSP and external circuitry. The GPIO port has eight I/O pins
(GPIO0–GPIO7) that are controlled through a memory-mapped register. Each GPIO
pin may be individually programmed as an output or as an input.
7.2 GPIO PROGRAMMING MODEL
The GPIO pins are controlled through the GPIO control/data Register (GPIOR),
which is illustrated in Figure 7-1. The register is described in the following
paragraphs.
7.3 GPIO REGISTER (GPIOR)
The GPIO Register (GPIOR) is a 24-bit read/write control/data register used to
operate and configure the GPIO pins. The control bits in the GPIOR select the
direction of data transfer for each pin, whereas the data bits in the GPIOR are used to
read from or write to the GPIO pins. Hardware reset and software reset clear all the
bits in GPIOR. The GPIOR bits are described in the following paragraphs.
Figure 7-1 GPIO Control/Data Register
GD0
0GPIOR
X:$FFF7
GD1
1
GD2
2
GD3
34567
GDD0
8
GDD1
9
GDD2
10
GDD3
1112131415
GC0
16
GC1
17
GC2
18
GC3
1920212223
AA0441.11
GD4GD5GD6GD7
GDD4GDD5GDD6GDD7
GC4GC5GC6
GC7