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PCx — Port Control Bit x
0 = Corresponding pin is configured as GPIO pin
1 = Corresponding pin is configured as UART pin
At reset, these bits are cleared to zero.
C.9.9 UART Data Direction Register (UDDR)
This register controls the direction of UART GPIO pins.
U0DDR — UART0 Data Direction Register
U1DDR — UART1 Data Direction Register
15
14
13
12
R
0
0
0
0
W
RESET:
PDCx — Port Direction Control Bit x
0 = Corresponding GPIO pin is configured as input
1 = Corresponding GPIO pin is configured as output
At reset, these bits are cleared to zero.
C.9.10 UART Port Data Register (UPDR)
The UART port data register is used to read or write data to or from UART GPIO pins.
U0PDR — UART0 Port Data Register
U1PDR — UART1 Port Data Register
15
14
13
12
R
0
0
0
0
W
RESET:
X = Undefined
PDx — Port Data Bit x
These bits are used to read or write data from/to the corresponding port pins if they
are configured as GPIO (by PC[3:0] bits in UPCR). If a port pin x is configured as a
GPIO input, then the corresponding PDx bit will reflect the value present on this pin. If
a port pin x is configured as a GPIO output, then the value written into the corre-
sponding PDx bit will be reflected on the pin.
Note that since the CTS and RTS pins are not present for UART1, the corresponding
port control register bits should be configured in a manner which provides determinis-
tic data when the port data register is read. One method for doing this is to configure
the missing pins as general-purpose outputs.
MMC2001
REFERENCE MANUAL
All manuals and user guides at all-guides.com
Freescale Semiconductor, Inc.
11
10
9
8
0
0
0
0
Figure C-44 UART Data Direction Register
11
10
9
8
0
0
0
0
Figure C-45 UART Port Data Register
PROGRAMMING REFERENCE
For More Information On This Product,
Go to: www.freescale.com
7
6
5
4
0
0
0
0
PDC3 PDC2 PDC1 PDC0
7
6
5
4
0
0
0
0
PD3
1000908C
1000A08C
3
2
1
0
0
0
0
0
1000908E
1000A08E
3
2
1
0
PD2
PD1
PD0
X
X
X
X
MOTOROLA
C-45
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