By increasing their usability, applicability, and quality of results (QoR), high-level synthesis (HLS) solutions are proving that they can fulfill their initial promise. One day, not using HLS will be like not using RTL synthesis today. And that day will not be long. Many hardware engineers are already changing how they get things done by making HLS an integral part of their design methodology.
What they've discovered is that the benefits of HLS not only profit the companies that adopt it; but hardware engineers who acquire the HLS skills to work at both the ESL and RTL are more valued and sought after than their counterparts, especially as increasingly complex designs and market pressures grant HLS-savvy engineers an undisputed competitive advantage. HLS makes their jobs easier and more productive because it shortens the time to verified, production-ready RTL.
However, the pool of potential HLS users is larger than those who have adopted it. Why haven't all hardware engineers gotten on board the HLS gravy train? As is typical when we fundamentally change the way we do things, there are technological, practical, and psychological hurdles. Development of the associated tools and methodologies is largely a response to the first two, followed by the removal of the last hurdle as the engineering community begins to perceive that these things have indeed reached maturity.
There are three clear signs that at least some HLS tools and methodologies have reached maturity.
1. A shortened time to first results
2. A broader application scope
3. Improved quality of results
Already, users of HLS are making it known that this is a technology with street cred. And now that tools like Catapult C Synthesis offer mixed language support and full-chip synthesis, HLS has truly arrived as a capable technology, proving itself with production quality results among a growing community of users.
Productizing time to results
One of the signs that a technology has matured is that it can be quickly put to useful advantage. Because of their steep learning curve and lack of refinements, the time to get to first design is longer with less mature tools than with the replaced methodology. A positive return on investment (ROI) isn't realized until the second design. However, more developed and perfected tools produce an ROI on the first design even with the requisite learning curve. In part, this is because mature HLS tools are better defined in terms of how they should be used and integrated, so it is easy to understand how they fit into the overall design flow. This makes them easier to adopt and deploy, shortening the time to first results.
HLS does require a change in the way engineers think about the design processes. So HLS tools must present information in a way that is familiar, highly transparent, and easy to understand. The user interface should clearly present all the familiar design aspects that engineers need to control or manipulate, guiding them to use the tool to the best effect. Engineers make the decisions; the HLS tool implements them while giving engineers full control over the results through full visibility, constraints, and analysis. This yields a flexible, more efficient and productive way of getting the job done.
Figure 1: Catapult C Synthesis makes it easy to optimize hardware by applying architectural constraints.
Click on image to enlarge.