Automatic Synthesis of Device Drivers for Hardware/Software Co-design

Automatically synthesizing device drivers, the hardware and software needed to interface a device to a processor, is an important element of hardware/software co-design. Driver software consists of the sequences of instructions needed for the processor to control its interactions with the device. Driver hardware consists of the digital logic necessary to physically connect the devices and generate signal events while meeting timing constraints. We describe an approach that begins with device speci cations in the form of timing and state diagrams and determines which signals can be controlled directly from software and which require indirect control through intervening hardware. Minimizing this hardware requires solving a simultaneous scheduling and partitioning problem whose goal is to limit the number of wires whose events are not directly generated by the processor software. We show that even the simplest version of this problem is NP-hard and discuss a heuristic solution that should work well in practical situations. Supported in part by an NSF Graduate Fellowship. y Supported by PYI Award (MIP-8858782) and by the DARPA/CSTO Microsystems Program under an ONR monitored contract (N00014-91-J-4041).