Datasheet

Functional Description
164 Intel® Xeon® Processor D-1500 Product Family
Datasheet - Volume 1 of 4: Integrated Platform Controller Hub
March 2015
• Setting up the temperature calculation equations.
3.21.3.7 SMBus Rules
Intel® Xeon® Processor D-1500 Product Family may NACK an incoming SMBus
transaction. In certain cases Intel® Xeon® Processor D-1500 Product Family will NACK
the address, and in other cases it will NACK the command depending on internal
conditions (such as errors, busy conditions). Given that most of the cases are due to
internal conditions, the external controller must alias a NACK of the command and a
NACK of the address to the same behavior. The controller must not try to make any
determination of the reason for the NACK, based on the type of NACK (command
versus address).
Intel® Xeon® Processor D-1500 Product Family will NACK when it is enabled but busy.
The external controller is required to retry up to 3 times when they are NACK'ed. In
reality if there is a NACK because of Intel® Xeon® Processor D-1500 Product Family
being busy, in almost all cases the next read will succeed since the update internally
takes very little time. In the case of a long delay, the external controller must assume
that Intel® Xeon® Processor D-1500 Product Family will never return good data.
3.21.3.7.1 During Block Read
On the Block Read, Intel® Xeon® Processor D-1500 Product Family will respect the
NACK and Stop indications from the external controller, but will consider this an error
case. It will recover from this case and correctly handle the next SMBus request.
Intel® Xeon® Processor D-1500 Product Family will honor STOP during the block read
command and cease providing data. On the next Block Read, the data will start with
byte 0 again. However, this is not a recommended usage except for 'emergency cases'.
In general the external controller should read the entire length of data that was
originally programmed.
3.21.3.7.2 Power On
On the Block Read, Intel® Xeon® Processor D-1500 Product Family will respect the
NACK and Stop indications from the external controller, but will consider this an error
case. It will recover from this case and correctly handle the next SMBus request.
Intel® Xeon® Processor D-1500 Product Family will honor STOP during the block read
command and cease providing data. On the next Block Read, the data will start with
byte 0 again. However, this is not a recommended usage except for 'emergency cases'.
In general the external controller should read the entire length of data that was
originally programmed.
3.21.3.8 Case for Considerations
Below are some corner cases and some possible actions that the external controller
could take.
A 1-byte sequence number is available to the data read by the external controller. Each
time Intel® Xeon® Processor D-1500 Product Family updates the thermal information
it will increment the sequence number. The external controller can use this value as an
indication that the thermal FW is actually operating. The sequence number will roll over
to 00h when it reaches FFh.
1. Power on: