LM3S6422 Luminary Micro, Inc, LM3S6422 Datasheet - Page 168

• Manufacturer Part Number: LM3S6422
• Description: Lm3s6422 Arm Microcontroller
• Manufacturer: Luminary Micro, Inc

Reset
Reset
Type
Type
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
Offset 0x520
Type R/W, reset 0x0000.0001
168
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 169). 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
R/W
R/W
19
0
3
0
R/W
R/W
18
0
2
0
July 25, 2008
R/W
R/W
17
0
1
0
R/W
R/W
16
0
0
1