Reset Classification
257
SLAU356I – March 2015 – Revised June 2019
Copyright © 2015–2019, Texas Instruments Incorporated
Reset Controller (RSTCTL)
3.2.4 Class 3 : Soft Reset
A Soft Reset is initiated under user application control and is a deterministic event. This class resets only
the execution-related components of the system. All other application related configuration is maintained,
thereby retaining the application's view of the device. Peripherals that are configured by the application
continue their operation through a Soft Reset.
From an application perspective, a Soft Reset has the following implications:
•
Resets the following execution related components in the system:
–
SYSRESETn of the Cortex-M4. All bus transactions in the M4 (except the debug PPB space) are
aborted.
–
WDT module.
•
All system-level bus transactions are maintained.
•
All peripheral configurations are maintained.
•
Returns control to the user code.
•
Debugger connection to the device is maintained.
•
It does NOT reboot the device.
•
On-chip SRAM values are retained
NOTE:
The Soft Reset class sets status flag registers that report the exact source of the Soft Reset.
An application can use these registers to select the necessary course of action. Refer to
device specific datasheet for details on the available Soft Reset sources.
NOTE:
A Soft Reset is activated whenever a reset that is higher in class is active.
NOTE:
The Cortex-M4 processor can initiate an 'processor only' Reset using the VECTRESET bit in
the Cortex-M4 Application Interrupt and Reset Control (AIRCR) Register. This reset is not
visible outside of the M4, and the user application must mange this condition when using this
reset.
Alternatively, the SYSRESETREQ bit of the same register can be used to generate a Hard
Reset on the device.