Intel 64 and IA-32 Architectures Software Developers Manual Volume 3A, System Programming Guide, Part 1

Vol. 3A 13-15
POWER AND THERMAL MANAGEMENT
See Figure 13-9 for the layout of IA32_THERM_INTERRUPT MSR. Bit fields include:
• High-Temperature Interrupt Enable (bit 0, R/W) — This bit allows the BIOS
to enable the generation of an interrupt on the transition from low-temperature
to a high-temperature threshold. Bit 0 = 0 (default) disables interrupts;
bit 0 = 1 enables interrupts.
• Low-Temperature Interrupt Enable (bit 1, R/W) — This bit allows the BIOS
to enable the generation of an interrupt on the transition from high-temperature
to a low-temperature. Bit 0 = 0 (default) disables interrupts; bit 0 = 1 enables
interrupts.
• THERMTRIP# Interrupt Enable (bit 2, R/W) — When a catastrophic cooling
failure occurs, the processor will automatically shutdown. Bit 2 = 0 disables the
feature; bit 2 = 1 enables the feature.
• FORCPR# Interrupt Enable (bit 3, R/W) — When a source external to the
processor asserts PROCHOT#, the processor will throttle. Bit 3 = 0 disables the
feature; bit 3 = 1 enables the feature.
• Overheat Interrupt Enable (bit 4, R/W) — Enables the generation of an
interrupt when an overheat temperature [>Tj(Max)] is reached. Bit 4 = 0
disables the feature; bit 4 = 1 enables the feature.
• Threshold #1 Value (bits 14:8, R/W) — A temperature relative to Tj(Max)
used to generate an interrupt when the Threshold #1 Interrupt Enable bit is set
and the actual relative temperature reaches or crosses this value.
• Threshold #1 Interrupt Enable (bit 15, R/W) — Enables the generation of
an interrupt when the actual temperature relative to Tj(Max) reaches the value
specified in Threshold #1 value. Bit 15 = 0 disables the feature; bit 15 = 1
enables the feature.
• Threshold #2 Value (bits 22:16, R/W) — A temperature relative to Tj(Max)
used to generate an interrupt when the Threshold #2 Interrupt Enable bit is set
and the actual relative temperature reaches or crosses this value.
• Threshold #2 Interrupt Enable (bit 23, R/W) — Enables the generation of
an interrupt when the actual temperature relative to Tj(Max) reaches the value
specified in Threshold #2 value. Bit 23 = 0 disables the feature; bit 23 = 1
enables the feature.