Functional Peripherals Registers
140
SLAU356I – March 2015 – Revised June 2019
Copyright © 2015–2019, Texas Instruments Incorporated
Cortex-M4F Peripherals
2.4.5.4
AIRCR Register (Offset = D0Ch) [reset = FA050000h]
Register mask: FFFF7FFFh
AIRCR is shown in
and described in
.
Application Interrupt/Reset Control Register. Use the Application Interrupt and Reset Control Register to:
determine data endianness, clear all active state information for debug or to recover from a hard failure,
execute a system reset, alter the priority grouping position (binary point).
Figure 2-54. AIRCR Register
31
30
29
28
27
26
25
24
VECTKEY
W-FA05h
23
22
21
20
19
18
17
16
VECTKEY
W-FA05h
15
14
13
12
11
10
9
8
ENDIANESS
RESERVED
PRIGROUP
R-0
R/W-0h
R/W-0h
7
6
5
4
3
2
1
0
RESERVED
SYSRESETRE
Q
VECTCLRACTI
VE
VECTRESET
R/W-0h
W-0h
W-0h
W-0h
Table 2-62. AIRCR Register Field Descriptions
Bit
Field
Type
Reset
Description
31-16
VECTKEY
W
FA05h
Register key. Writing to this register requires 0x5FA in the VECTKEY
field. Otherwise the write value is ignored.
15
ENDIANESS
R
0h
Data endianness bit. ENDIANNESS is sampled from the BIGEND
input port during reset. You cannot change ENDIANNESS outside of
reset.
0b (R/W) = little endian
1b (R/W) = big endian
14-11
RESERVED
R/W
0h
10-8
PRIGROUP
R/W
0h
Interrupt priority grouping field. The PRIGROUP field is a binary
point position indicator for creating subpriorities for exceptions that
share the same preemption level. It divides the PRI_n field in the
Interrupt Priority Register into a preemption level and a subpriority
level. The binary point is a left-of value. This means that the
PRIGROUP value represents a point starting at the left of the Least
Significant Bit (LSB). This is bit [0] of 7:0. The lowest value might not
be 0 depending on the number of bits allocated for priorities, and
implementation choices
7-3
RESERVED
R/W
0h
2
SYSRESETREQ
W
0h
Causes a signal to be asserted to the outer system that indicates a
reset is requested. Intended to force a large system reset of all major
components except for debug. Setting this bit does not prevent
Halting Debug from running.
1
VECTCLRACTIVE
W
0h
Clears all active state information for active NMI, fault, and
interrupts. It is the responsibility of the application to reinitialize the
stack. The VECTCLRACTIVE bit is for returning to a known state
during debug. The VECTCLRACTIVE bit self-clears. IPSR is not
cleared by this operation. So, if used by an application, it must only
be used at the base level of activation, or within a system handler
whose active bit can be set.