INTRODUCTION
MOTOROLA
PORT C
6 - 3
6.1
INTRODUCTION
Port C is a triple-function I/O port with nine pins (see Figure 6-1). Three of the nine pins
can be configured as general-purpose I/O or as the serial communication interface (SCI)
pins. The other six pins can also be configured as GPIO, or they can be configured as the
synchronous serial interface (SSI) pins.
When configured as general-purpose I/O, port C can be used for device control. When the
pins are configured as serial interfaces, port C provides a convenient connection to other
DSPs, processors, codecs, digital-to-analog and analog-to-digital converters, and any of
several transducers. This section describes all three port C functions as well as examples
of how to configure and use each function.
EXTERNAL ADDRESS
SWITCH
EXTERNAL DATA
SWITCH
BUS
CONTROL
HOST/DMA
PARALLEL
INTERFACE
SCI
INTERFACE
SSI
INTERFACE
PORT
A
I/0
(47)
PORT
C
I/0
(9)
PORT
B
I/0
(15)
A0 - A15
D0 - D23
PS
DS
X/Y
RD
WR
BN
BR
BG
WT
BS
—
—
—
—
—
—
—
—
—
—
—
—
PB0 - PB7
PB8
PB9
PB10
PB11
PB12
PB13
PB14
PC0
PC1
PC2
PC3
PC4
PC5
PC6
PC7
PC8
H0 - H7
HA0
HA1
HA2
HR/W
HEN
HREQ
HACK or PB14
RXD
TXD
SCLK
SC0
SC1
SC2
SCK
SRD
STD
DEFAULT
FUNCTION
ALTERNATE
FUNCTION
8
8
24
16
Figure 6-1 Port C Interface
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