SPRUJF2A March 2026 – March 2026 AM13E23019
After a device reset occurs, the lowest level reset cause which occurred during reset processing is captured in hardware so that application software can interrogate the reason for the reset and take any appropriate action when starting the application. The lowest level reset cause is encoded into a 5-bit field in the reset cause register in SYSCTL. The contents of the reset cause register are always cleared upon a read, and return zero after being read if no reset has occurred after the read. The reset cause encoding is provided in the table below.
| Reset | Device Modules Reset | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Reset Level | Cause ID | Reset Cause | NRST/JTAG/SWD Disables | SHUTDN STOREx | Core Regulator | Debug Subsystem | SRAM | BCR/BSL Execution | IOMUX | DMA, FLASHCTL, SYSCTL | Peripherals | CPU | |
| N/A | 0x00 | 0 | No reset since last read | ||||||||||
| POR | 0x01 | 1 | VDD < POR- Violation | R | R | R | R | R | R | R | R | R | R |
| PMU Trim Parity Fault | |||||||||||||
| SHUTDNSTOREx Parity Fault | |||||||||||||
| 0x02 | 2 | NRST Pin Reset (=>1sec) | R | R | R | R | R | R | R | R | R | R | |
| 0x03 | 3 | Software-triggered POR | R | R | R | R | R | R | R | R | R | R | |
| BOR | 0x04 | 4 | VDD < BOR- Violation | R | R | R | R | R | R | R | R | ||
| 0x05 | 5 | Wake from SHUTDOWN | R | R | R | R | R(1) | R | R | R | |||
| 0x06-0x8 | 6-8 | Reserved | |||||||||||
| BOOTRST | 0x09 | 9 | Fatal Clock Fault | R | R | R | R | R | R | ||||
| 0x0A-0x0B | 10-11 | Reserved | |||||||||||
| 0x0C | 12 | NRST Pin Reset (< 1sec) | R | R | R(2) | R | R | R | |||||
| 0x0D | 13 | Software-triggered BOOTRST | R | R | R(2) | R | R | R | |||||
| 0x0E | 14 | WWDT0 Violation | R | R | R(2) | R | R | R | |||||
| 0x0F | 15 | Reserved | |||||||||||
| SYSRST | 0x10 | 16 | BSL Exit | R | R(2) | R(3) | R | R | |||||
| 0x11 | 17 | BSL Entry | R | R(2) | R(3) | R | R | ||||||
| 0x12-0x13 | 18-19 | Reserved | |||||||||||
| 0x14 | 20 | Uncorrectable Flash ECC Error | R(2) | R(3) | R | R | |||||||
| 0x15 | 21 | CPU Lockup Violation | R(2) | R(3) | R | R | |||||||
| 0x16-0x19 | 22-25 | Reserved | |||||||||||
| 0x1A | 26 | Debug-triggered SYSRST | R(2) | R(3) | R | R | |||||||
| 0x1B | 27 | Software-triggered SYSRST | R(2) | R(3) | R | R | |||||||
| CPURST | 0x1C | 28 | Debug-triggered CPURST | R | |||||||||
| 0x1D | 29 | Software-triggered CPURST | R | ||||||||||
| 0x1E-0x1F | 30-31 | Reserved | |||||||||||
If two reset causes occur simultaneously, the lowest cause reset ID value is prioritized and reported. For example, if a WWDT0 violation (cause 0x0E) occurs at the same time that a VDD < BOR- violation (cause 0x04) occurs, the reported reset cause is a BOR- violation (cause 0x04), as this is a lower level reset which clears additional aspects of the device state.
The reset cause encoding enables simple software handling during application startup. The reset cause value can be read by application software and tested to be within a certain value range to determine if the following occurred: