5.1. Minimum Functionality for a Configurable Logical Device
The minimum functionality configurable Plug and Play logical device identifies itself through the Plug and Play process. The device also provides complete resource data and must accept configuration commands from Plug and Play software. The configuration registers must be read/write. The logical devices must not use any resources except for those assigned. This means that a device that has previous default resource settings must either use the new resource settings upon being activated or become inactive until it is re-configured in its own proprietary way. Cards must report their actual active status when the Activate register is read.
This minimum function exists to support logical devices that are re-configurable using other, different, methods, such as EISA configuration. In order for this type of device to participate in the Plug and Play process, the configuration of the device must be readable using Plug and Play standard registers. This is done by both reading the device 's resource data structure and reading the device 's configuration registers.