System Management: IPMC Watchdog Timer Commands
ATCA-9305 User’s Manual 10009109-01
7-16
1. Potential race conditions exist with implementation of this option. If the Set Watchdog Timer command is
sent just before a pretime-out interrupt or time-out is set to occur, the time-out could occur before the
command is executed. To avoid this condition, it is recommended that software set this value no closer
than three counts before the pretime-out or time-out value is reached.
Get Watchdog Timer Command
This command retrieves the current settings and present countdown of the watchdog
timer. The Timer Use Expiration flags in byte 5 retain their states across system resets and
system power cycles. With the exception of bit 6 in the Timer Use byte, the Timer Use Expi-
ration flags are cleared using the Set Watchdog Timer command. They may also become
cleared because of a loss of IPMC power, firmware update, or other cause of IPMC hard
reset. Bit 6 of the Timer Use byte is automatically cleared to 0b whenever the timer times
out, is stopped when the system is powered down, enters a sleep state, or is reset.
Table 7-10: Get Watchdog Timer Command
Request Data
(continued)
4 Timer Use Expiration flags clear
(0b=leave alone, 1b=clear timer use expiration bit)
[7] reserved
[6] reserved
[5] OEM
[4] SMS/OS
[3] OS Load
[2] Monitor/POST
[1] Monitor FRB-2
[0] reserved
5 Initial countdown value, lsbyte (100 ms/count)
6 Initial countdown value, msbyte
Response Data 1 Completion Code
Type: Byte: Data Field:
Request Data — —
Response Data 1 Completion Code
Type: Byte: Data Field: (continued)