Accessing PCI Configuration Space
In Windows Me/98, and Windows 2000 and later, an adapter driver can access its adapter card's PCI configuration space at IRQL PASSIVE_LEVEL by using the IRP_MN_READ_CONFIG and IRP_MN_WRITE_CONFIG requests.
In Windows 2000 and later, PCI driver stacks export the BUS_INTERFACE_STANDARD interface, which provides access to the PCI configuration space at IRQL DISPATCH_LEVEL.
For more information, see Accessing Device Configuration Space.
Build date: 11/16/2013