Reporting Power Management Events to the Host Bridge

HT provides two System Management messages that can be used to report power management events to the host.

  • STPCLK message — uses the SMAF field to define the type of event being reported and the action to be taken. The SMAF field encoding is not defined by the HT specification.

  • SMI message — used to notify (interrupt) the processor when a system management event occurs. The SMI message can support power management as will as other features. (Note: SMI is an x86 legacy signal and is discussed in more detail in “X86 CPU Compatibility” on page 491.)

Message transmission may be stimulated by either hardware or software. A system that supports power management will very likely include a set of registers ...

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