Thermal Sensing Device Registers; Thermal Reference Registers; Command Byte Bit Assignment - Intel P9500 - Core 2 Duo 2.53 GHz 6M L2 Cache 1066MHz FSB Socket P Mobile Processor Manual

Table 6-13. Command Byte Bit Assignment
Register
RESERVED
RRT
RS
RC
RCR
RESERVED
RESERVED
RRHL
RRLL
WC
WCR
RESERVED
RESERVED
WRHL
WRLL
OSHT
RESERVED
All of the commands are for reading or writing registers in the thermal sensor except
the one-shot command (OSHT). The one-shot command forces the immediate start of
a new voltage-to-temperature conversion cycle. If a conversion is in progress when the
one-shot command is received, then the command is ignored. If the thermal sensing
device is in standby mode when the one-shot command is received, a conversion is
performed and the sensor returns to standby mode. If the thermal sensor is in auto-
convert mode and is between conversions, then the conversion rate timer resets, and
the next automatic conversion takes place after a full delay elapses. Please refer to
Section 6.7.4
The default command after reset is the reserved value (00h). After reset, receive byte
packets will return invalid data until another command is sent to the thermal sensing
device.
6.7

Thermal Sensing Device Registers

The system management software can configure and control the thermal sensor by
writing to and interacting with different registers in the thermal sensor. These registers
include a thermal reference register, two thermal limit registers, a status register, a
configuration register, a conversion rate register, and other reserved registers. The
following subsections describe the registers in detail.
6.7.1

Thermal Reference Registers

The processor core and thermal sensing device internal thermal reference registers
contain the thermal reference value of the thermal sensing device and the processor
core thermal diodes. This value ranges from +127 to –128 decimal and is expressed as
a two's complement, eight-bit number. These registers are saturating, that is, values
above 127 are represented at 127 decimal, and values below –128 are represented as
–128 decimal.
88
Command Reset State
00h N/A
01h N/A
02h N/A
03h 0000 0000
04h 0000 0010
05h 0111 1111
06h 1100 1001
07h 0111 1111
08h 1100 1001
09h N/A
0Ah N/A
0Bh N/A
0Ch N/A
0Dh N/A
0Eh N/A
0Fh N/A
10h – FFh N/A
for further detail on standby and auto-convert modes.
Dual-Core Intel
System Management Feature Specifications
Function
Reserved for future use.
Read processor core thermal data.
Read status byte (flags, busy signal).
Read configuration byte.
Read conversion rate byte.
Reserved for future use.
Reserved for future use.
Read processor core thermal diode T
Read processor core thermal diode T
Write configuration byte.
Write conversion rate byte.
Reserved for future use.
Reserved for future use.
Write processor core thermal diode T
Write processor core thermal diode T
One shot command (use send byte packet).
Reserved for future use.
® ®
Itanium Processor 9000 and 9100 Series Datasheet
limit.
HIGH
limit.
LOW
limit.
HIGH
limit.
LOW