Fault Handling
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SLAU356I – March 2015 – Revised June 2019
Copyright © 2015–2019, Texas Instruments Incorporated
Cortex-M4F Processor
If a bus fault occurs during a stack push when entering a bus fault handler, the bus fault does not escalate
to a hard fault. Thus if a corrupted stack causes a fault, the fault handler executes even though the stack
push for the handler failed. The fault handler operates but the stack contents are corrupted.
NOTE:
Only Reset and NMI can preempt the fixed priority hard fault. A hard fault can preempt any
exception other than Reset, NMI, or another hard fault.
1.6.3 Fault Status Registers and Fault Address Registers
The fault status registers indicate the cause of a fault. For bus faults and memory management faults, the
fault address register indicates the address accessed by the operation that caused the fault, as shown in
.
Table 1-11. Fault Status and Fault Address Registers
Handler
Status Register Name
Address Register Name
Hard fault
Hard Fault Status Register (HFSR)
Hard Fault Status Register (HFSR)
Memory management
fault
Memory Management Fault Status Register (MMFSR)
Configurable Fault Status Register (CFSR)
Bus fault
Bus Fault Status Register (BFSR)
Configurable Fault Status Register (CFSR)
Usage fault
Usage Fault Status Register (UFSR)
Configurable Fault Status Register (CFSR)
NOTE:
MMFSR, BFSR and UFSR together form the Configurable Fault Status (CFSR) register. See
for more details.
1.6.4 Lockup
The processor enters a lockup state if a hard fault occurs when executing the NMI or hard fault handlers.
When the processor is in the lockup state, it does not execute any instructions. The processor remains in
lockup state until it is reset, an NMI occurs, or it is halted by a debugger.
NOTE:
If the lockup state occurs from the NMI handler, a subsequent NMI does not cause the
processor to leave the lockup state.
1.7
Power Management
The Cortex-M4F processor sleep modes reduce power consumption:
•
Sleep mode stops the processor clock.
•
Deep-sleep mode switches off the Flash memory, powers down the digital logic and puts under
retention.
The processor fully implements the Wait For Interrupt (WFI) and Wait For Event (WFE). In addition, the
processor also supports the use of SLEEPONEXIT, that causes the processor core to enter sleep mode
when it returns from an exception handler to Thread mode.
MSP432P4xx implementation also supports the processor to be put into various very low-power sleep
modes and capability to wakeup from certain predefined events.
NOTE:
For details on the mechanisms of entry to and exit from various low-power modes, see the
Power Control Manager (PCM)
chapter.