Watchdog Timer; System Event Log (Sel) - Intel SE7520AF2 Technical Product Specification

Intel® Server Board SE7520AF2 TPS
6.2.6.1 Wake On LAN in S4/S5
A configuration option is provided that allows the on-board NICs to be enabled to wake the
system in an S4/S5 state, even if the operating system disabled Wake-On-LAN when it powered
down the system. This provides an option for users who want to use standard, but non-secure,
WOL capability for operations such as after-hours maintenance. Note that the DPC LAN
capability provides a secure system power-up, plus the ability to provide BIOS boot options, by
sending authenticated IPMI messages directly to the BMC via the on-board NICs.
6.2.7

Watchdog Timer

The mBMC implements an IPMI 1.5-compatible watchdog timer. See the IPMI specification for
details. SMI and NMI pre-timeout actions are supported, as are hard reset, power down, and
power cycle timeout actions.
6.2.8

System Event Log (SEL)

The mBMC implements the logical System Event Log device as specified in the Intelligent
Platform Management Interface Specification, v1.5. The SEL is accessible via all
communication transports. In this way, the SEL information can be accessed while the system is
down by means of out-of-band interfaces. The maximum SEL size that is supported by mBMC
is 92 entries.
Supported commands are:
− Get SEL Info
−
Reserve SEL
− Get SEL Entry
− Add SEL Entry
− Clear SEL
− Get SEL Time
− Set SEL Time
6.2.8.1 Timestamp Clock
The management controller (mBMC or BMC) maintains a four-byte internal timestamp clock
used by the SEL and SDR subsystems. This clock is incremented once per second. It is read
using the Get SEL Time command and set using the Set SEL Time command. The Get SDR
Time command can also be used to read the timestamp clock. These commands are specified
in the Intelligent Platform Management Interface Specification, v1.5.
After a reset or power up, the management controller sets the initial value of the timestamp
clock to 0x00000000. It is incremented once per second after that. A SEL event containing a
timestamp from 0x00000000 to 0x140000000 has a timestamp value that is relative to
management controller initialization.
During POST, the BIOS tells the management controller the current time via the Set SEL Time
command. The management controller maintains this time, incrementing it once per second,
until the controller is reset or the time is changed via another Set SEL Time command.
Revision 1.2
Intel order number C77866-003
Platform Management
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