Plug and Play (PnP) refers to the ability of a computer system to automatically configure expansion boards and other devices. With a Plug and Play device or software, the user should be able to add, play or remove a device without being forced to manually configure hardware or the operating system. For example, a user can plug in a USB keyboard and Plug and Play will detect the new device, find a driver for it and install it. PnP has become a design philosophy and set of specifications that describe hardware and software changes to the PC and its peripherals, making it possible to add new components without having to perform technical procedures. In the architecture of Universal Plug and Play (UPnP), the concepts of PnP are extended to the whole networked world.
Genereally speaking, Plug-and-Play's task is to match up physical devices with the corresponding software such as device drivers and to establish channels of communication between each physical device and its driver. PnP need to allocate the following "bus-resources" to both drivers and hardware: I/O addresses, memory regions, IRQs, DMA channels (ISA bus only). ThisPnP assignment of bus-resources is sometimes called "configuring" but it is only a low level type of configuring.
A Plug and Play system requires the combined interaction of the personal computer's BIOS, hardware components, device drivers, and operating system software. The basic system board implementation and BIOS support required for Plug and Play support under Windows 2000 are defined in the ACPI specification.
The ACPI specification defines a new interface between the operating system and the personal computer's Plug and Play and power management features. The ACPI methods defined are independent of the actual operating system or CPU. ACPI specifies a register-level interface to core Plug and Play and power management functions and defines a descriptive interface for additional hardware features. This gives system designers the ability to implement a range of Plug and Play and power management features with different hardware designs while using the same operating-system driver. ACPI also provides a generic system-event mechanism for Plug and Play and power management.
In addition to the ACPI specification, other hardware support is defined in industry standards, such as Universal Serial Bus, Version 1.0, PCI Local Bus Specification, Revision 2.1, or PCMCIA standards, and in the Plug and Play specifications.
Related Terms: ACPI, PCMCIA, Device Driver, Windows 2000, UPnP
Reference Links:
http://www.tldp.org/HOWTO/Plug-and-Play-HOWTO.html: Plug and Play How To
http://www.upnp.org: The Official Site of UPnP™ Forum