Specifications

B
Sensor alarm troubleshooting
125
IOH Die temperature sensor (10h)
The Intel 5520 IOH provides an on-die temperature measurement which can be accessed via the
on-die Thermal Sensor Fan-Speed Control Register (IOH TSFSC). This field contains the difference
between the die temperature and the maximum permissible die temperature. The register has a
resolution of 0.5° C. Hence, a value in the range of 0 to 127 refers to a temperature difference of 0 to
63.5° C lower than the maximum permissible die temperature. A value in the range of 128 to 255
refers to a temperature difference of 64 to 0.5° C above the maximum permissible die temperature.
For differences exceeding these limits, the register values are clamped at 63.5° C for the lower range
and 64° C for the upper range.
When the CPM first powers up, the X86 processor complex configures and enables the IOH on-die
temperature sensor operations. The CPM acquires IOH on-die temperature via address 0xE0 on I
2
C
bus 2 and present the readings in the range as negative units in the range of [0, -64] below the
internal maximum permissible temperature.
Sensor alarm troubleshooting
Table 38 recommends actions to take when the sensors generate alarms or events.
Table 38. Sensor alarms and recommended actions (sheet 1 of 14)
Number Name Alarm level Possible errors or faults Recommendation
00h ATCA FRU Hot
Swap
N/A M7 state Remove CPM and reinsert to see if problem persists.
If problem still persists, then remove CPM and
contact customer support.
01h AMC FRU Hot
Swap
N/A M7 state Remove CPM and reinsert to see if problem persists.
If problem still persists, then remove CPM and
contact customer support.
02h RTM FRU Hot
Swap
N/A M7 state Remove CPM and reinsert to see if problem persists.
If problem still persists, then remove CPM and
contact customer support.
03h Version Change N/A Sensor puts an event into the
SEL when a change as been
detected.
No action required; information only.
04h Ejector Closed N/A None No action required; information only.
05h RTM Present N/A None No action required; information only.
06h AMC Present N/A None No action required; information only.