Alert Standard Format (ASF) Specification

Alert Standard Format (ASF) Specification v2.0 DMTF Document DSP0136
DSP0136 23 April 2003 Page 79 of 94
A. Bit Mask De-assertion Event – true if all of the following are true:
i) Bit 0 of the entry’s Alert Device Address field is cleared (0b).
ii) The entire current
status is cleared and any bit in the past status is set.
B. Compare Byte De-assertion Event – true if all of the following are true:
i) Bit 0 of the entry’s Alert Device Address field is set (1b).
ii) A bit in the current
status is different than the corresponding bit in the past status.
iii) The current
value does not match the entry’s Alert Compare Value and the past
value does match the entry’s Alert Compare Value.
5. The current
status is copied into the past status.
6.2 ASF-Sensor Devices
An ASF-Sensor device must meet the requirements detailed in this section and implement the
following ASF SMBus commands:
• Get Event Data message for ASF Sensors (section 5.1.1.1)
• Get Event Status message for ASF Sensors (section 5.1.1.2)
• Device Type Poll message (section 5.3.1)
This specification recommends that an ASF-sensor support all
SMBus 2.0 protocols, including
those required for discovery via ARP. Lower-cost, fixed-address ASF-sensor devices can be
“discovered” by an alert-sending device via the managed client’s firmware methods, see section 4
for more information.
Note: Some SMBus 1.x and 2.0 host controllers do not support the SMBus 2.0 "Block Write-
Block Read Process Call" transaction necessary to issue the Get Event Data and Get Event
Status messages. An ASF-sensor designer might want to take this into consideration and design
an alternate interface to enable the host controller to access the device’s event status and data.
6.2.1 Device Identification
New sensor devices must implement the 128-bit Unique Device Identifier (UDID) as defined by
[SMBUS_2.0]. New sensor devices that have fixed addresses are not required to support the full
ARP command set; support for the directed Get UDID command is the only requirement. If a
fixed-address device is not discoverable, the managed client’s firmware publishes the device’s
fixed address in the ASF_ADDR information record.
Recommended: New fixed-address ASF-sensor devices support the ARP commands necessary
to support device discovery.
The UDID content is summarized below, but the format and content is controlled by
[SMBUS_2.0].
8
bits
8
bits
16
bits
16
bits
16
bits
16
bits
16
bits
32
bits
Device
Capabilities
Version /
Revision
Vendor
ID
Device
ID
Interface Subsystem
Vendor ID
Subsystem
Device ID
Vendor
Specific ID
MSB LSB
Device
Capabilities
Describes the device’s capabilities, including the device’s address
type and PEC support indications.
Version / Revision
UDID version number, and silicon revision identification.
Vendor ID
The device manufacturer’s ID as assigned by the SBS Implementers’
Forum or the PCI SIG.
Device ID
The device ID as assigned by the device manufacturer (identified by
the Vendor ID field).
Interface
Identifies the protocol layer interfaces supported over the SMBus