LM3S1138 Luminary Micro, Inc, LM3S1138 Datasheet - Page 191

• Manufacturer Part Number: LM3S1138
• Description: Lm3s1138 Arm Microcontroller
• Manufacturer: Luminary Micro, Inc

Reset
Reset
Type
Type
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
July 26, 2008
Bit/Field
31:0
R/W
R/W
31
15
0
0
R/W
R/W
Register 19: GPIO Lock (GPIOLOCK), offset 0x520
The GPIOLOCK register enables write access to the GPIOCR register (see page 192). Writing
0x1ACC.E551 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.
30
14
0
0
R/W
R/W
29
13
0
0
Name
LOCK
R/W
R/W
28
12
0
0
R/W
R/W
27
11
0
0
Type
R/W
R/W
R/W
26
10
0
0
0x0000.0001
Reset
R/W
R/W
25
0
9
0
Preliminary
R/W
R/W
24
0
8
0
Description
GPIO Lock
A write of the value 0x1ACC.E551 unlocks the GPIO Commit (GPIOCR)
register for write access.
A write of any other value or a write to the GPIOCR register reapplies
the lock, preventing any register updates. A read of this register returns
the following values:
0x0000.0001
0x0000.0000
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
LM3S1138 Microcontroller
R/W
R/W
19
0
3
0
R/W
R/W
18
0
2
0
R/W
R/W
17
0
1
0
R/W
R/W
16
0
0
1
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