ADLINK CoreExpress-ECO2 - Manual (Page 19)

4.10 Get last System Restart Event
This command reads the cause of the last System Restart. The returned code is explained in Table
4.10.2.
START SMC_addr ACK command ACK START (Repeat) SMC_addr+1 ACK
length ACK(C) data ACK(C) STOP
Table 4.10.1 SMC transmitter format of the System Restart Event Command Code
ITEM DESCRIPTION
START SM-bus start condition
SMC_addr 0x50 (8-bit)
ACK SM-bus acknowledge condition generated by receiver
command 0x36 = “System Restart Event” Command code
length 0x01 = 1 Bytes data length
data
Data-Byte containing the cause of the last restart
0x00: UNKNOWN
Unknown Reason of Restart (should never reported)
0x20: SW_RESET
A reset by Software caused the Restart of the system
0x30: HW_RESET
A reset by Hardware caused the Restart of the system (e.g. Reset-Button)
0x40: WATCHDOG
The Watchdog has restarted the system
0x50: BIOS_FAULT
Main-BIOS is corrupted -> boot from Backup BIOS
0x60: POWER_DOWN
The system was Shutdown (e.g. Power-Button, ACPI Shutdown)
0x70: POWER_LOSS
The system is restarted after a Power-loss (e.g. external Power supply
instable or switched off while the system was running)
0x80: POWER_CYCLE
The system is restarted after a Power-cycle (e.g. internal Power supply has
failed)
0x90: VIN_DROP
The system is restarted after a Voltage Drop of the Main-Input-Voltage
0xA0: PWR_FAIL
The system is restarted after a PWRFAIL detection of an internal power
supply circuit
STOP SM-bus stop condition
Table 4.10.2 Explanation of Table 4.10.1