Mobile PC docking systems allow docking of a PC, with additional hardware capabilities. A docking station allows the end user to add other devices to the mobile PC system—for example, sound, network adapter, hard disks, CD-ROM, different display adapter, SCSI, modems, and so on.
Docking systems can support hot, warm, or cold docking. Warm docking refers to docking and undocking the mobile PC while the system is in a low power state (as defined in the ACPI 1.0 specification) but is not powered off. Hot docking refers to docking and undocking the mobile PC while the system is operating at full power and is in an active working state.
Resource conflicts can occur when a mobile PC is paired with a docking station that allows users to add non-proprietary expansion cards to the system. For a mobile PC and docking station pair, the system designer must ensure that the docking system is capable of arbitrating resources for conflicts that might occur if an expansion card is added to the docking station. However, the system designer does not need to add to the mobile PC unit all of the Basic PC 98 resource-arbitration capabilities.
The requirements in this section apply for mobile designs that include a docking station. There is no requirement that a mobile PC must have a docking station.
16. Mobile PC/docking station combination meets PC 98 requirements
Required
Manufacturers must submit the combined docking station and mobile PC for PC 98 compatibility testing, and this combination must pass testing.
The docking unit must be able to power the mobile system and charge the mobile system’s battery under the control of the mobile system.
Some PC 98 requirements might apply to a mobile PC/docking station combination that do not apply to the mobile PC as a standalone unit. The intent for PC 98 is that such requirements apply only because of facilities present in the docking station. For example, if a docking station provides graphics capabilities that substitute for the graphics capabilities of the mobile unit, the Basic PC 98 graphics requirements apply for the mobile PC/docking station combination when the substituted graphics component is in use. If the mobile PC is supplying all graphics capabilities, then Mobile PC 98 graphics requirements still apply.
17. Docking station meets all Basic PC 98 requirements
Required
The PC 98 requirements, as defined in the “Basic PC 98” chapter in Part 2 of this guide, include requirements for OnNow and ACPI, Plug and Play, and bus and device specifications.
All PC 98 Plug and Play requirements must be met if the docking station allows addition of non-proprietary devices. Complete compliance is not necessary if the docking station does not allow addition of non-proprietary devices.
The docking station must meet the PC 98 BIOS requirement for multiple adapters and multiple monitors, which allows for the graphics capabilities in the mobile unit to be fully operational (either the LCD panel or external connector) in the event that an user adds another graphics adapter to the docking station.
Many docking stations support VCR-style docking in which the notebook is closed when docked, so the user is prevented from accessing the notebook display. It is recommended that users not be precluded from accessing their notebook display when docked and that users have the option of simultaneously using the main display on the docking station and the notebook display.
Note: The docking station can support expansion capabilities through user-accessible ISA connectors, although such designs are discouraged for PC 98. It is expected that 1998 is the last year ISA will be allowed for end-user expansion in docking stations.
18. Docking station interface is supported using ACPI-defined mechanisms
Required
The docking station interface must be implemented using mechanisms defined in the ACPI 1.0 specification. Non-Plug and Play devices are enumerated using ACPI. All notification events and docking control must be implemented as defined in Sections 5.6.3 and 6.3 of the ACPI 1.0 specification.
19. Mobile PC/docking station combination supports automatic resource assignment and dynamic disable capabilities
Required
The mobile PC unit that is part of a docking system does not require all of the resource-arbitration capabilities required for expandable PC systems. However, the system as a whole must be capable of completely and dynamically disabling add-on devices and of freeing all the resources used by that device when the mobile unit is docked. This requirement excludes fixed-resource devices such as the DMA controller, interrupt controller, and so on.
With this capability, individual devices in the mobile PC will be disabled when it is docked, allowing the appropriate devices in the docking station to be enabled.
The system could fail if an add-on card requires resources that conflict with a device on either the mobile PC or the docking station. The mobile PC/docking station combination must be able to resolve resource conflicts among all the devices in the docking system.
This means that docking station devices must be available to replace disabled devices in the mobile PC, and these devices must meet the basic Plug and Play resource arbitration requirements for PC 98, as described in the “Basic PC 98 General Device Requirements” section in the “Basic PC 98” chapter. However, it is up to the design engineer of a mobile PC/docking station combination to determine which component (mobile PC or docking station) will resolve the conflict when the mobile unit is docked.
For more information about resource arbitration when two devices such as two keyboards or two mice are present, see the “Automatic resource assignment and dynamic disable capabilities are supported” requirement in the “I/O Ports and Devices” chapter in Part 4 of this guide.
20. Docking station supports warm docking
Required
Recommended: Support hot docking.
Docking or undocking a mobile unit from a docking station must not require powering off the system and must not require a system reboot.
Removable IDE devices are not required to meet this requirement.
21. Docking system supports fail-safe docking
Required
The system must provide a fail-safe system for docking and undocking the mobile unit. Working in conjunction with the operating system and ACPI (as defined in Sections 6.3 and 5.63 of the ACPI 1.0 specification), the mechanism for fail-safe docking must ensure the following:
There is no requirement for mechanical lockout to block the user from removing the mobile unit without operating-system notification.