Cortex-M3 Processor (Reference Material)
UG0331 User Guide Revision 15.0
108
3.7.2.7
Configuration and Control Register
The CCR controls entry to Thread mode and enables:
•
the handlers for NMI, HardFault and faults escalated by FAULTMASK to ignore BusFaults
•
trapping of divide by zero and unaligned accesses
•
access to the STIR by unprivileged software, see
"Software Trigger Interrupt Register" on page 93
.
See the register summary in
page 102 for the CCR attributes.
The bit assignments are:
Figure 36 •
CCR Bit Assignments
[1]
SLEEPONEXIT
Indicates sleep-on-exit when returning from Handler mode to Thread mode:
0: do not sleep when returning to Thread mode.
1: enter sleep, or deep sleep, on return from an ISR.
Setting this bit to 1 enables an interrupt driven application to avoid returning to an empty
main application.
[0]
Reserved.
Table 58 •
CCR Bit Assignments
Bits
Name
Function
[31:10]
Reserved.
[9]
STKALIGN
Indicates stack alignment on exception entry:
0: 4-byte aligned
1: 8-byte aligned.
On exception entry, the processor uses bit[9] of the stacked PSR to indicate the
stack alignment. On return from the exception it uses this stacked bit to restore
the correct stack alignment.
[8]
BFHFNMIGN
Enables handlers with priority -1 or -2 to ignore data BusFaults caused by load
and store instructions. This applies to the HardFault, NMI, and FAULTMASK
escalated handlers:
0: data BusFaults caused by load and store instructions cause a lock-up
1: data BusFaults caused by load and store instructions are ignored.
Set this bit to 1 only when the handler and its data are in absolutely safe memory.
The normal use of this bit is to probe system devices and bridges to detect
problems.
Table 57 •
SCR Bit Assignments
(continued)
Bits
Name
Function
DIV_0_TRP
Reserved
UNALIGN_TRP
NONBASETHRDENA
USERSETMPEND
BFHFNMIGN
STKALIGN
Reserved
31
10 9 8 7
5 4 3 2 1 0
Reserved
Содержание SmartFusion2 MSS
Страница 1: ...UG0331 User Guide SmartFusion2 Microcontroller Subsystem ...
Страница 166: ...Cortex M3 Processor Reference Material UG0331 User Guide Revision 15 0 132 ...
Страница 200: ...Embedded NVM eNVM Controllers UG0331 User Guide Revision 15 0 166 Figure 87 System Builder Window ...
Страница 407: ...Universal Serial Bus OTG Controller UG0331 User Guide Revision 15 0 373 ...
Страница 806: ...Fabric Interface Controller UG0331 User Guide Revision 15 0 772 Figure 345 FIC Master AHB Lite Subsystem ...