Vast is the creation of Graham Hellestrand, president and chief executive officer, who has also been R&D manager of a medical ultrasound engineering company and a professor of computer science and engineering at the University of New South Wales, Sydney, Australia. EDA veteran Bill Goerke is chairman of the board. The 15-person company has a development group in Sydney, and is building an engineering and marketing team in Santa Clara.

Comet makes it possible to create an executable "virtual system prototype" representing both hardware and software, perform interactive partitioning, and run very fast simulations. Through its highly abstracted Virtual Processor Models (VPMs), the product promises simulation speeds as fast as 150 million instructions/second, while maintaining timing accuracy across the hardware/software interface.

That speed, said Hellestrand, lets software designers do real work before prototype hardware is available. "This is a new tool in the systems-engineering space that, for the first time, allows designers to build real hardware and software and run models very quickly," he said.

By allowing hardware descriptions using behavioral C code, Comet also promises hardware simulations at speeds 200 to 2,000 times faster than register-transfer level (RTL) simulation.

Designers can use Comet before and after hardware/software partitioning. They enter design descriptions using some combination of VHDL, Verilog, C or C++. Comet thus differs from other codesign tools that are based on proprietary or highly specialized system-level design languages. "We're giving designers a tool set that fits in with design flows at the moment," said Hellestrand.

There is always a trade-off between speed and accuracy, and Vast believes it's found the sweet spot with VPMs. According to Hellestrand, these processor models contain a knowledge of the target assembler, cache, interrupt structure, bus structure, DMA and memory. "We abstract out a lot of the details, but it doesn't lose accuracy in terms of input-output timing, including cache misses, pipeline hazards and exceptions," he said.

Vast has developed VPMs for such processors as the Motorola 68000/68030, MIPS R3000/4000, ARM7, ARM9, Sparc V8 and Intel 80386. Vast has an embedded operating system that runs on the VPMs, and claims to be working with three top commercial real-time operating system (RTOS) providers to port their products to Comet.

Hellestrand said Vast started life in Sydney as part of a four-year R&D contract. However, most of the CPU modeling and integration work has been done in the United States.

Comet version 2.3 has been shipping to a few early customers in the United States, Japan and Australia since August. With the next release, version 2.4, Vast intends to take a much stronger public profile and introduce itself to a worldwide engineering audience.