Plug and Play for SCSI Host Adapters and Peripherals

This section summarizes the Plug and Play requirements for SCSI devices.

11. All components comply with Plug and Play SCSI specifications

Each component must comply with Plug and Play SCSI Specification 1.0 and the related Plug and Play host bus specification (for example, PCI v. 2.1 if the PCI bus is used).

Notice, however, that the SCAM specification is optional, not required.

12. Plug and Play device identifier

• For a system board device, there must be a Plug and Play device-specific ID.
• The device must provide device identifiers as defined in the Plug and Play SCSI Specification.

13. Automatic resource assignment and dynamic disable capabilities

For peripheral devices, the system must be capable of automatically assigning, disabling, and relocating the resources used by this device when necessary. Changing or adding this device to the system must not require changing jumpers or switches on either the adapter or the system board. In the event of an irreconcilable conflict with other devices for assigning resources, the operating system must be able to disable the device to prevent the system from stalling.

14. Flexible resource configuration for each non-PCI device

If the host adapter uses a non-PCI bus such as an ISA bus, the SCSI host adapter must be capable of supporting the following minimum resource configuration options:

• Support 2 I/O locations

  Recommended: 7 I/O locations

• Support 4 IRQ signals

  Recommended: 7 IRQ signals

• Support 3 DMA channel selections, if DMA is used

If the minimum resource requirements cannot be met, then IRQ sharing must be implemented, as specified in the "ISA" chapter in Part 3 of this guide.