LM3S316 Luminary Micro, Inc., LM3S316 Datasheet - Page 138

• Manufacturer Part Number: LM3S316
• Description: Microcontroller
• Manufacturer: Luminary Micro, Inc.

General-Purpose Input/Outputs (GPIOs)
138
Reset
Reset
Type
Type
Bit/Field
31:8
GPIO Open Drain Select (GPIOODR)
Offset 0x50C
7:0
RO
RO
31
15
0
0
Register 14: GPIO Open Drain Select (GPIOODR), offset 0x50C
The GPIOODR register is the open drain control register. Setting a bit in this register enables the
open drain configuration of the corresponding GPIO pad. When open drain mode is enabled, the
corresponding bit should also be set in the GPIO Digital Input Enable (GPIODEN) register (see
page 142). Corresponding bits in the drive strength registers (GPIODR2R, GPIODR4R,
GPIODR8R, and GPIOSLR) can be set to achieve the desired rise and fall times. The GPIO acts
as an open drain input if the corresponding bit in the GPIODIR register is set to 0; and as an open
drain output when set to 1.
When using the I
PB2 and PB3 should be set to 1 (see examples in “Initialization and Configuration” on page 121).
RO
RO
30
14
0
0
reserved
Name
ODE
RO
RO
29
13
0
0
RO
RO
28
12
0
0
reserved
2
C module, the GPIO Alternate Function Select (GPIOAFSEL) register bit for
Type
R/W
RO
RO
RO
27
11
0
0
RO
RO
26
10
0
0
Reset
0x00
0
RO
RO
25
0
9
0
Preliminary
Description
Reserved bits return an indeterminate value, and should never
be changed.
Output Pad Open Drain Enable
0: Open drain configuration is disabled.
1: Open drain configuration is enabled.
RO
RO
24
0
8
0
reserved
R/W
RO
23
0
7
0
R/W
RO
22
0
6
0
R/W
RO
21
0
5
0
R/W
RO
20
0
4
0
ODE
R/W
RO
19
0
3
0
R/W
RO
18
0
2
0
April 27, 2007
R/W
RO
17
0
1
0
R/W
RO
16
0
0
0