Compaq ProLiant 6500 PCI Hot Plug Technology - Page 6

ECG080/0698 TECHNOLOGY BRIEF (cont.) ... Hot-Plug Controller and Slot-Specific Power Control The hot-plug electronics designed by Compaq consist of two separate elements: the hot-plug controller and the slot-specific power control. Compaq designed its hot-plug controller to manage the following components: • PCI Bus. The controller communicates with isolation devices on the PCI bus to electrically isolate a single PCI slot from the rest of the system. Slot isolation permits insertion or removal of an adapter without interruption to the server or other active adapters. • Power. The controller receives a command from the OS to power up or power down a single PCI slot. To perform this function, the controller uses the slot-specific power control. The slot-specific power-control electronics allow the proper power sequencing on the PCI bus and guarantee safe control of the power to the individual PCI adapters. • Slot LED Indicators. The hot-plug controller also governs the slot LEDs. In Compaq's implementation of hot-plug hardware, each slot has a green and an amber LED to indicate slot status. The green LED indicates power to the slot and flashes while performing a power state change; the amber LED indicates that the slot requires attention. • PCI Hot Plug Button. This feature is available only on Compaq's latest PCI Hot Plug servers. The button is pressed to signal the software to initiate a power state change. While the button is more convenient, the same functionality is provided through the software interface. Each slot has its own button to indicate which slot is to be addressed by the supporting software. System Chassis Design In addition to the electrical components, the overall system design (system chassis and other hardware) has been adapted for safety and ease of adapter installation and removal. Chassis design changes include quick-release latches on the adapter slots to allow fast and easy removal and insertion of adapters; wider slot spacing and flexible slot separators to allow users to remove and insert adapters without electrically contacting (shorting) other components; and a top access shield that allows users access to adapters yet prevents access to other internal components. These design changes meet or exceed all regulatory safety standards. System Software PCI Hot Plug technology is supported by Microsoft, Novell, and SCO. While Compaq has worked to ensure that each OS is compatible with the PCI requirements, user interface applications may vary from one OS to another since each user interface is optimized for that OS. Each OS supplier has defined interface layers between the hot-plug hardware and the OS kernel to support PCI Hot Plug technology. Hardware and Software Control In a typical scenario in which the administrator adds an adapter to an empty slot, the following steps occur while the system is running: 1. The administrator prepares the slot for installation of the adapter by opening the appropriate slot release lever and removing the expansion slot cover. 2. The administrator installs the adapter into the appropriate expansion slot. 3. The administrator closes the slot release lever. 6