Compaq ProLiant 7000 PCI Hot Plug Technology - Page 5

ECG080/0698 TECHNOLOGY BRIEF (cont.) ... • Developed the Compaq ProLiant 6500 and ProLiant 7000, announced in August 1997, as the first available server platforms conforming to the PCI Hot Plug Specification and added nextgeneration PCI Hot Plug features to Pentium II Xeon Models of the ProLiant 7000 announced in June 1998. Compaq is in a unique position to lead this standardization effort. Not only is Compaq a pioneer in the development of systems hardware, but Compaq also has extensive experience in systems configuration software and device driver development. Because of its unique position, Compaq has been able to gather the support of major software developers and IHVs to deliver PCI Hot Plug technology as an open, industry standard. SUMMARY OF PCI HOT PLUG Taking a very general approach, a fully capable hot-plug system includes the hot-plug system hardware, hot-plug aware software and OS support, hot-plug capable device drivers, and a hotplug aware user interface, as shown in Figure 1. The hardware and software work together to ensure that any hot-plug activity occurring on the PCI bus is benign to other devices on the PCI bus. User Interface Software and OS Support Device Drivers PCI Adapter Board HoSty-sPtleugm Hardware Figure 1: Generic PCI Hot Plug Technology System Hardware It is important to note that while the PCI Hot Plug Specification identifies the technical requirements of a hot-plug capable system, it does not specify the implementation of this technology. In the specific implementation that Compaq developed, the PCI Hot Plug hardware isolates a single PCI slot from all other devices on the PCI bus. Compaq's PCI Hot Plug system hardware performs two main functions: • Powers down a single adapter slot, allowing insertion and removal of adapters • Protects the system and other adapters from the electrical effects of hot-plug operations 5