LM3S817 Datasheet, PDF (135/379 Pages) List of Unclassifed Manufacturers – Microcontroller

General-Purpose Input/Outputs (GPIOs)
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 140). 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.
GPIO Open Drain Select (GPIOODR)
Offset 0x50C
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
ODE
Type
RO
RO
RO
RO
RO
RO
RO
RO
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Reset
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Bit/Field
31:8
7:0
Name
reserved
ODE
Type
RO
R/W
Reset
0
0x00
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.
136
May 4, 2007
Preliminary