LM3S308 Datasheet, PDF (55/537 Pages) Texas Instruments – ARM and Thumb are registered trademarks and Cortex is a trademark

Stellaris^® LM3S308 Microcontroller
Register 18: Priority Mask Register (PRIMASK)
The PRIMASK register prevents activation of all exceptions with programmable priority. Reset,
non-maskable interrupt (NMI), and hard fault are the only exceptions with fixed priority. Exceptions
should be disabled when they might impact the timing of critical tasks. This register is only accessible
in privileged mode. The MSR and MRS instructions are used to access the PRIMASK register, and
the CPS instruction may be used to change the value of the PRIMASK register. See the
Cortex™-M3/M4 Instruction Set Technical User's Manual for more information on these instructions.
For more information on exception priority levels, see “Exception Types” on page 68.
Priority Mask Register (PRIMASK)
Type R/W, reset 0x0000.0000
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
PRIMASK
Type RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
R/W
Reset
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Bit/Field
31:1
0
Name
reserved
PRIMASK
Type
Reset Description
RO 0x0000.000 Software should not rely on the value of a reserved bit. To provide
compatibility with future products, the value of a reserved bit should be
preserved across a read-modify-write operation.
R/W
0
Priority Mask
Value Description
1 Prevents the activation of all exceptions with configurable
priority.
0 No effect.
June 18, 2012
55
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