Hardware/software co-design comes of age

The concurrent design and verification of hardware and software has become a reality thanks to a plethora of resources in ESL flows, emulation, modeling and standards, and more.

There once was a time when system design was completely serial. Entire hardware platforms were designed, prototyped, debugged, and virtually completed before any software development began. Of course, such methodologies corresponded to the days of much broader market windows. The very idea of such a quaint approach is enough to make one snicker.

Today, it’s quite different. Those market windows have narrowed to a sliver. Hardware development typically lags far behind software, but no one can afford to wait for hardware prototypes to begin shaking out the system’s drivers, operating system, and bus protocols. It’s become imperative for the software-development process to begin as early as possible so the software and hardware can be verified together.

But how is this to be done when silicon is essentially unavailable, or at best difficult to gain access to? Additionally, in this early stage of a system design cycle, the final specifications are a moving target. There’s the problem of setting up a testbench for the device. Often, the information on which you’ll base debug and performance analysis is incomplete. And on top of all of that, the hardware platform itself includes heterogeneous multicores with complex interconnect, memory hierarchy, and multiple dependent software stacks.

Fortunately for design teams, the means by which software can be effectively verified for a substantially non-existent hardware platform have come a long way. To be sure, one part of the solution has been an increased reliance on so-called platform systems-on-a-chip (SoCs), a genericized hardware architecture that draws from an established, known-good IP portfolio. Such methodologies can help stack the deck in favor of the design team when it comes to software development.

But for those intrepid souls looking to build on a customized hardware platform, hardware/software co-design generally entails assembling a highly abstract model of the hardware platform. There are a number of approaches to this methodology. Additionally, emulation technology has improved substantially in recent years, making it easier to run more clock cycles’ worth of simulation with slightly more detailed models. And, standardization activity of late has helped the industry get on the same page with its modeling.