Table of Contents
Advertisement
11.5 GPIO Pins and Registers
The GPIO functionality of UART pins is controlled by three registers: the port control
register (UPCR), data direction register (UDDR), and port data register (UPDR).
11.5.1 UART Port Control Register (UPCR)
The read/write UART port control register controls the functionality of UART GPIO
pins.
U0PCR — UART0 Port Control Register
U1PCR — UART1 Port Control Register
15
14
13
12
R
0
0
0
0
W
RESET:
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.
11.5.2 UART Data Direction Register (UDDR)
The read/write UART data direction 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:
MOTOROLA
UNIVERSAL ASYNCHRONOUS RECEIVER/TRANSMITTER MODULE
11-16
Freescale Semiconductor, Inc.
Table 11-4 UART Pins GPIO Assignment
GPIO Bit
P0
P1
P2
P3
11
10
9
8
0
0
0
0
Figure 11-9 UART Port Control Register
11
10
9
8
0
0
0
0
Figure 11-10 UART Data Direction Register
For More Information On This Product,
Go to: www.freescale.com
UART Pin
RXD
TXD
RTS
CTS
7
6
5
4
0
0
0
0
PC3
7
6
5
4
0
0
0
0
PDC3 PDC2 PDC1 PDC0
1000908A
1000A08A
3
2
1
0
PC2
PC1
PC0
0
0
0
0
1000908C
1000A08C
3
2
1
0
0
0
0
0
MMC2001
REFERENCE MANUAL
Advertisement
Table of Contents
