Register 20: Base Priority Mask Register (BASEPRI)
The
BASEPRI
register defines the minimum priority for exception processing. When
BASEPRI
is
set to a nonzero value, it prevents the activation of all exceptions with the same or lower priority
level as the
BASEPRI
value. Exceptions should be disabled when they might impact the timing of
critical tasks. This register is only accessible in privileged mode. For more information on exception
priority levels, see “Exception Types” on page 114.
Base Priority Mask Register (BASEPRI)
Type RW, reset 0x0000.0000
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
reserved
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
RO
Type
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Reset
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
reserved
BASEPRI
reserved
RO
RO
RO
RO
RO
RW
RW
RW
RO
RO
RO
RO
RO
RO
RO
RO
Type
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Reset
Description
Reset
Type
Name
Bit/Field
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.
0x0000.00
RO
reserved
31:8
Base Priority
Any exception that has a programmable priority level with the same or
lower priority as the value of this field is masked. The
PRIMASK
register
can be used to mask all exceptions with programmable priority levels.
Higher priority exceptions have lower priority levels.
Description
Value
All exceptions are unmasked.
0x0
All exceptions with priority level 1-7 are masked.
0x1
All exceptions with priority level 2-7 are masked.
0x2
All exceptions with priority level 3-7 are masked.
0x3
All exceptions with priority level 4-7 are masked.
0x4
All exceptions with priority level 5-7 are masked.
0x5
All exceptions with priority level 6-7 are masked.
0x6
All exceptions with priority level 7 are masked.
0x7
0x0
RW
BASEPRI
7:5
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.
0x0
RO
reserved
4:0
June 18, 2014
98
Texas Instruments-Production Data
The Cortex-M4F Processor