The low-level interface between software and hardware has always been a challenge for embedded systems software and firmware developers. Every last detail has got to be right: the bits, the sequences, and the timing, or else that peripheral device will just refuse to operate correctly. Recently, a new category of embedded systems software development tool has appeared which provides automaton support for the construction of code for device drivers. This class of tools, known as Device Driver Development Environments (3DEs), is built around special-purpose "knowledge bases" that contain detailed information about the structure and operation of specific microprocessors and peripheral devices. Once a user specifies the functional behaviors that a device should exhibit, source code will be tiled together automatically to provide those functions, as well as boot code, interrupt service routines and test/exercise software. 3DE tools are raising the level of abstraction at which hardware/software interface programming issues are addressed.