LM3S1911-IRN20-A0T Luminary Micro, Inc., LM3S1911-IRN20-A0T Datasheet - Page 178

• Manufacturer Part Number: LM3S1911-IRN20-A0T
• Description: Microcontroller
• Manufacturer: Luminary Micro, Inc.

General-Purpose Input/Outputs (GPIOs)
GPIO Lock (GPIOLOCK)
GPIO Port A base: 0x4000.4000
GPIO Port B base: 0x4000.5000
GPIO Port C base: 0x4000.6000
GPIO Port D base: 0x4000.7000
GPIO Port E base: 0x4002.4000
GPIO Port F base: 0x4002.5000
GPIO Port G base: 0x4002.6000
GPIO Port H base: 0x4002.7000
Offset 0x520
Type R/W, reset 0x0000.0001
178
Reset
Reset
Type
Type
Bit/Field
31:0
R/W
R/W
31
15
0
0
Register 19: GPIO Lock (GPIOLOCK), offset 0x520
The GPIOLOCK register enables write access to the GPIOCR register (see page 179). Writing
0x1ACCE551 to the GPIOLOCK register will unlock the GPIOCR register. Writing any other value
to the GPIOLOCK register re-enables the locked state. Reading the GPIOLOCK register returns
the lock status rather than the 32-bit value that was previously written. Therefore, when write accesses
are disabled, or locked, reading the GPIOLOCK register returns 0x00000001. When write accesses
are enabled, or unlocked, reading the GPIOLOCK register returns 0x00000000.
R/W
R/W
30
14
0
0
Name
LOCK
R/W
R/W
29
13
0
0
R/W
R/W
28
12
0
0
R/W
R/W
Type
27
11
R/W
0
0
R/W
R/W
26
10
0x0000.0001
0
0
Reset
R/W
R/W
25
0
9
0
Preliminary
Description
GPIO Lock
A write of the value 0x1ACCE551 unlocks the GPIO Commit (GPIOCR)
register for write access. A write of any other value reapplies the lock,
preventing any register updates. A read of this register returns the
following values:
R/W
R/W
0x0000.0001
0x0000.0000
24
0
8
0
LOCK
LOCK
Value
R/W
R/W
23
0
7
0
Description
locked
unlocked
R/W
R/W
22
0
6
0
R/W
R/W
21
0
5
0
R/W
R/W
20
0
4
0
R/W
R/W
19
0
3
0
R/W
R/W
18
0
2
0
October 09, 2007
R/W
R/W
17
0
1
0
R/W
R/W
16
0
0
1