Technical specifications
8.5 Hardware descriptions
SIMATIC IPC377G
86 Operating Instructions, 07/2022, A5E51366314-AB
SIO logic device 8 CR F2h
Watchdog state register (Page 86)
SIO logic device 7 CR FDh
Battery status register (Page 87)
For more information and reference code for accessing to Super IO, contact Siemens
Technical support.
8.5.5.2 Watchdog control register
Bit Read/Write
Meaning of the bits
Watchdog Timer I Pulse or Level mode select:
• 0: Pulse mode
• 1: Level mode
Select Watchdog Timer I count mode.
• 0: Second Mode.
• 1: Minute Mode.
8.5.5.3 Watchdog counter register
Bit Read/Write
Meaning of the bits
0 to 7 Read/Write Watch Dog Timer I Time-out value. Writing a non-zero value to the
register causes the counter to load the value into the Watch Dog Counter
and start counting down. The accuracy of watchdog timer I about one
cycle deviation. Non-zero value will be reloaded to the Watch Dog Counter
and the countdown resumes. Reading the register returns the current
value in the Watch Dog Counter but not the Watch Dog Timer Time-out
value.
• 00h: Time-out Disable
• 01h: Time-out occurs after one cycle time, the cycle time is based on
LD8 CRF0, bit[3], by analogy.
8.5.5.4 Watchdog state register
Bit Read/Write
Meaning of the bits
Trigger Watchdog Timer I event. This bit is self-clearing.