Register 58: Application Interrupt and Reset Control (APINT), offset 0xD0C
Note:
This register can only be accessed from privileged mode.
The
APINT
register provides priority grouping control for the exception model, endian status for
data accesses, and reset control of the system. To write to this register, 0x05FA must be written to
the
VECTKEY
field, otherwise the write is ignored.
The
PRIGROUP
field indicates the position of the binary point that splits the
INTx
fields in the
Interrupt Priority (PRIx)
registers into separate group priority and subpriority fields. Table
3-9 on page 171 shows how the
PRIGROUP
value controls this split. The bit numbers in the Group
Priority Field and Subpriority Field columns in the table refer to the bits in the
INTA
field. For the
INTB
field, the corresponding bits are 15:13; for
INTC
, 23:21; and for
INTD
, 31:29.
Note:
Determining preemption of an exception uses only the group priority field.
Table 3-9. Interrupt Priority Levels
Subpriorities
Group
Priorities
Subpriority Field
Group Priority Field
Binary Point
a
PRIGROUP
Bit Field
1
8
None
[7:5]
bxxx.
0x0 - 0x4
2
4
[5]
[7:6]
bxx.y
0x5
4
2
[6:5]
[7]
bx.yy
0x6
8
1
[7:5]
None
b.yyy
0x7
a.
INTx
field showing the binary point. An x denotes a group priority field bit, and a y denotes a subpriority field bit.
Application Interrupt and Reset Control (APINT)
Base 0xE000.E000
Offset 0xD0C
Type RW, reset 0xFA05.0000
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
VECTKEY
RW
RW
RW
RW
RW
RW
RW
RW
RW
RW
RW
RW
RW
RW
RW
RW
Type
1
0
1
0
0
0
0
0
0
1
0
1
1
1
1
1
Reset
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
VECTRESET
VECTCLRACT
SYSRESREQ
reserved
PRIGROUP
reserved
ENDIANESS
WO
WO
WO
RO
RO
RO
RO
RO
RW
RW
RW
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
Register Key
This field is used to guard against accidental writes to this register.
0x05FA must be written to this field in order to change the bits in this
register. On a read, 0xFA05 is returned.
0xFA05
RW
VECTKEY
31:16
Data Endianess
The Tiva™ C Series implementation uses only little-endian mode so
this is cleared to 0.
0
RO
ENDIANESS
15
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
14:11
171
June 18, 2014
Texas Instruments-Production Data
Tiva
™
TM4C1294NCPDT Microcontroller