Plug and Play (PnP) is a concept that means one can connect a device into a computer and it is automatically identified, recognized and configured to work in that system.
To be fully implemented, PnP needs three things.
- PnP BIOS: PnP BIOS enables PnP and detects PnP devices. The BIOS also reads the ESCD (Extended System Configuration Data) for configuration information on existing PnP devices.
- Extended System Configuration Data (ESCD): It is a file that contains information for installed PnP devices.
- PnP operating system: Any operating system, such as Windows XP, that supports PnP complete the configuration process started by the BIOS for each PnP devices.
PnP automated several key tasks:
- Interrupt Requests (IRQ): It is a hardware interrupt, used by various parts of a computer to get attention of a computer system.
- Direct Memory Access (DMA): It helps the device to access system memory without consulting the CPU first.
- Memory Addresses: It ensures that the hardware needs resources to operate properly.
- Input/Output (I/O) configuration: It defines the ports for receiving and sending data/information.