Emerson ATCA-9305 Manuel D’Utilisation

 IPMC Watchdog Timer Commands

ATCA-9305 User’s Manual

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.

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:

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

Request Data

—

—

Response Data

1

Completion Code

  (continued)