Alert Standard Format (ASF) Specification

Alert Standard Format (ASF) Specification v2.0 DMTF Document DSP0136
DSP0136 23 April 2003 Page 76 of 94
8 1 8 1 8 1 1
Data 2 A Data3 A PEC A P
Version Number
0001 0000
0 System State 0 [data dependent] 0
5.4 Remote-Control Device Action Message
An alert-sending device forces a remote control action to the managed client via a Remote-
Control Device Action message. If the managed client supports ASF-RMCP remote-control
actions, the client’s firmware publishes the remote-control device types and addresses via an
ASF-defined ACPI data structure (see 4.1.2.4 ASF_RCTL). That data structure contains the
Control Device Address, Control Command, and Control Data Value fields that the alert-sending
device uses in the SMBus message to force the device action.
The data returned by that ACPI control method indicates whether or not a remote-control device’s
command must include a PEC. An alert-sending device uses the SMBus Byte Write command to
initiate the remote-control action, either
… without a PEC:
1 7 1 1 8 1 8 1 1
S Slave Address Wr A Command A Write Data A P
Control Device Address 0 0 Control Command 0 Control Data Value 0
… or with a PEC:
1 7 1 1 8 1 8 1 8 1 1
S Slave Address Wr A Command A Write Data A PEC A P
Control Device Address 0 0 Control Command 0 Control Data Value 0 [data dependent] 0
5.5 Legacy Sensor Device Alert Poll Message
An alert-sending device polls legacy sensors to determine if status bits are set, indicating that an
alert should be sent. If the managed client supports ASF legacy-device alerts, the client’s
firmware publishes the legacy-device configuration and access information via an ASF-defined
ACPI data structure (see 4.1.2.2 ASF_ALRT). That structure contains the Alert Device Address
and Alert Command fields that the alert-sending device uses in the SMBus message to read the
legacy-device’s current status. The control method’s returned data also identifies compare
conditions as well as PET field data that the alert-sending device uses to format a PET frame if
the specified condition is active. See section 6.1.2 for additional information regarding the
methods an alert-sending device uses in the polling of legacy-device sensors.
The format of the message is an SMBus Byte Read transaction:
Caution
: This command is a Byte Read — an atomic write/read command. This is different than
a combination of 2 separate commands: Send Byte and Receive Byte. To avoid multi-master
problems, the atomic Byte Read must be used instead of the 2 individual commands.
1 7 1 1 8 1 1 7 1 1 8 1 1
S Slave Address Wr A Command A S Slave Address Rd A Read Result ~A P
Legacy Sensor
Device Address
0 0 Alert
Command
0 Legacy Sensor
Device Address
1 0 1