%T HCSP: Imperative State and True Concurrency
%A Adrian E. Lawrence
%E  James S. Pascoe,  Roger J. Loader,  Vaidy S. Sunderam
%B Communicating Process Architectures 2002
%X HCSP is an extension of CSPP which captures the semantics of
   hardware compilation. Because it is a superset of CSPP, it
   can describe both hardware and software and so is useful for
   co\-design. The extensions beyond CSPP include: true
   concurrency; new hardware constructors; and a simple and
   natural way to represent imperative state. Both CSPP and
   HCSP were invented to cope with problems that arose while
   the author was trying to prove that the hardware that he had
   designed correctly implemented channels between a processor
   and an FPGA. Standard CSP did not capture priority, yet the
   circuits in the FPGA and the occam processes in the
   transputer both depended on priority for their correctness.
   The attempt to extend CSP rigorously to handle such problems
   of co\-design has led to develoments that seem to have a
   much wider significance including a new way of unifying
   theories for imperative programming. This paper reports on
   the current state of HCSP and focuses on handling imperative
   state and true concurrency. The acceptance denotational
   semantics is described briefly.