MPC555
/
MPC556
QUEUED SERIAL MULTI-CHANNEL MODULE
MOTOROLA
USER’S MANUAL
Rev. 15 October 2000
14-9
14.6 QSMCM Pin Control Registers
lists the three QSMCM pin control registers.
The QSMCM uses 12 pins. Eleven of the pins, when not being used by the serial sub-
systems, form a parallel port on the MCU. (The ECK pin is a dedicated external clock
source.)
The port QS pin assignment register (PQSPAR) governs the usage of QSPI pins.
Clearing a bit assigns the corresponding pin to general-purpose I/O; setting a bit as-
signs the pin to the QSPI.
PQSPAR does not affect operation of the SCI. When the SCIx transmitter is disabled,
TXDx is a discrete output; when the SCIx receiver is disabled, RXDx is a discrete in-
put. When the SCIx transmitter or receiver is enabled, the associated TXDx or RXDx
pin is assigned its SCI function.
The port QS data direction register (DDRQS) determines whether QSPI pins are in-
puts or outputs. Clearing a bit makes the corresponding pin an input; setting a bit
makes the pin an output. DDRQS affects both QSPI function and I/O function.
summarizes the effect of DDRQS bits on QSPI pin function.
QSPI_IL
— QSPI Interrupt Level Register
0x30 5006
MSB
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
LSB
15
RESERVED
ILQSPI
RESET:
0
0
0
0
0
0
0
0
Table 14-6 QSPI_IL Bit Descriptions
Bit(s)
Name
Description
0:10
—
Reserved
11:15
ILQSPI
Interrupt level of SPI
00000 = lowest interrupt level request (level 0)
11111 = highest interrupt level request (level 31)
Table 14-7 QSMCM Pin Control Registers
Address
Register
0x30 5014
QSMCM Port Data Register (PORTQS)
See
14.6.1 Port QS Data Register (PORTQS)
for bit
descriptions.
0x30 5016
PORTQS Pin Assignment Register (PQSPAR)
See
for bit descriptions.
0x30 5017
PORTQS Data Direction Register (DDRQS)
See
for bit descriptions.
F
re
e
sc
a
le
S
e
m
ic
o
n
d
u
c
to
r,
I
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
n
c
.
..