TM4C123BH6PM Datasheet, PDF (660/1277 Pages) Texas Instruments – Tiva TM4C123BH6PM Microcontroller

General-Purpose Input/Outputs (GPIOs)
When using the I²C module, in addition to setting the GPIOAFSEL register bits for the I²C clock
and data pins, the data pins should be set to open drain using the GPIO Open Drain Select
(GPIOODR) register (see examples in “Initialization and Configuration” on page 644).
GPIO Alternate Function Select (GPIOAFSEL)
GPIO Port A (APB) base: 0x4000.4000
GPIO Port A (AHB) base: 0x4005.8000
GPIO Port B (APB) base: 0x4000.5000
GPIO Port B (AHB) base: 0x4005.9000
GPIO Port C (APB) base: 0x4000.6000
GPIO Port C (AHB) base: 0x4005.A000
GPIO Port D (APB) base: 0x4000.7000
GPIO Port D (AHB) base: 0x4005.B000
GPIO Port E (APB) base: 0x4002.4000
GPIO Port E (AHB) base: 0x4005.C000
GPIO Port F (APB) base: 0x4002.5000
GPIO Port F (AHB) base: 0x4005.D000
Offset 0x420
Type RW, reset -
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
reserved
Type RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
Reset
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
reserved
AFSEL
Type RO
RO
RO
RO
RO
RO
RO
RO
RW
RW
RW
RW
RW
RW
RW
RW
Reset
0
0
0
0
0
0
0
0
-
-
-
-
-
-
-
-
Bit/Field
31:8
7:0
Name
reserved
AFSEL
Type
RO
RW
Reset Description
0x0000.00 Software should not rely on the value of a reserved bit. To provide
compatibility with future products, the value of a reserved bit should be
preserved across a read-modify-write operation.
-
GPIO Alternate Function Select
Value Description
0 The associated pin functions as a GPIO and is controlled by
the GPIO registers.
1 The associated pin functions as a peripheral signal and is
controlled by the alternate hardware function.
The reset value for this register is 0x0000.0000 for GPIO ports
that are not listed in Table 10-1 on page 638.
660
June 12, 2014
Texas Instruments-Production Data