Device Drivers are specialised software that runs when hardware is plugged into a PC to allow the hardware to communicate with the operating system.

Operating Systems provide a large collection of Device Drivers for common device types (such as USB Mass Storage devices, Web Cams, etc...), where possible we will develop your embedded device to use one of these drivers. If your device cannot use one of the standard Device Drivers then you will need a custom driver.

With the latest releases of the Windows Driver Kit, Microsoft have implemented a new driver framework called Windows Driver Foundation (WDF) allowing drivers to be developed quicker and easier than was possible with previous driver models. The WDF allows drivers to be developed in two modes, Kernel Mode and User Mode.

User Mode Drivers have the advantage that they run outside the Windows Kernel removing the possibility of bugs in the driver crashing the operating system. This layer of protection unfortunately introduces performance issues meaning that User Mode Drivers are not suited for devices where a high data throughput and/or low latency is required, in these situations a Kernel Mode Driver is required.

As well as the throughput and latency advantages Kernel Mode Drivers also support more device types than User Mode Drivers so depending on your product may be a more applicable.

• Windows Driver Kit
• Windows Driver Foundation
• User Mode Drivers