HT Link Disconnect/Reconnect Sequence

The specification defines the ability of the HT bus to disconnect all of its links simultaneously. This mechanism uses the LDTSTOP# signal and NOP packet (with disconnect bit set) to gracefully disconnect and subsequently reconnect all links within the HT fabric. This feature has five specified uses:

  • Disconnecting HT links to conserve power

  • An alternate and faster method of changing link frequency and width during initialization, when compared to Soft Reset

  • Support for Host Voltage ID and Frequency ID (VID/FID) change

  • Processor is entering certain ACPI-specified states

  • System is entering certain ACPI-specified states

Regardless of the system motivation for asserting LDTSTOP# the sequence of events associated ...

Get HyperTransport™ System Architecture now with O’Reilly online learning.

O’Reilly members experience live online training, plus books, videos, and digital content from 200+ publishers.