SHIM: A Language for Hardware/Software Integration

Abstract

Virtually every system designed today is an amalgam of hardware and
software.  Unfortunately, software and circuits that communicate
across the hardware/software boundary are tedious and error-prone to
create.  This suggests a more automatic way to synthesize them.
                                                                                
I present the SHIM language, which combines imperative
C-like semantics for software and RTL-like semantics for hardware to
allow a unified description of hardware/software systems.  Hardware
processes and software functions communicate through shared variables,
hardware for which is automatically synthesized by the SHIM
compiler, which generates C and synthesizable VHDL.
                                                                                
I demonstrate the effectiveness of the language by re-implementing
an I2C bus controller.  The SHIM source is half the size of an
equivalent manual implementation, slightly faster, and has a smaller
memory footprint.  Partial and complete hardware implementations in
SHIM are also presented, showing that SHIM is succinct and
effective.