Motorola DSP56012 User Manual
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.
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
which is illustrated in
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.
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
0
GPIOR
X:$FFF7
X:$FFF7
GD1
1
GD2
2
GD3
3
4
5
6
7
GDD0
8
GDD1
9
GDD2
10
GDD3
11
12
13
14
15
GC0
16
GC1
17
GC2
18
GC3
19
20
21
22
23
AA0441.11
GD4
GD5
GD6
GD7
GDD4
GDD5
GDD6
GDD7
GC4
GC5
GC6
GC7