Accellera's SCE-API standard, approved just days before June's Design Automation Conference, brought to fruition years of work on a standard that defines a multichannel communication interface for emulation end users and suppliers. This interface allows software models describing system behavior to connect with structural models describing the implementation of that system. Each channel transports untimed messages (i.e., packets, burst transfers, etc.) of arbitrary abstraction between the channel's two end points, or ports.
These channels aren't meant to connect software models to each other. Rather, they connect software proxy models to message-port interfaces on the hardware side of the design. A software modeling and simulation environment, such as SystemC, provides the means to connect software models to each other. Though the software side of a system can be modeled at several different levels of abstraction, including untimed, cycle-accurate, and even gate-level models, the focus of SCE-MI Version 1.0 is to interface purely untimed software models with an RTL or gate-level DUT.
Essentially, the problem is that all emulators on the market today have proprietary application programming interfaces (APIs). This makes it difficult for verification IP to be created with the ability to port to the various emulators, restricting their usability by end users. SCE-API was developed for portability of transactor models between emulation vendors, so IP providers can write a single model that would work on all emulators (see the figure).
According to Accellera's Interfaces Committee chair, Brian Bailey, writing those models takes quite a bit of manpower. "But now, we're going to start seeing portability of those transactors models between various hardware systems," he says.
Models written with SCE-API compliance to run on, say, a Mentor V Station emulation system should also now run on the Aptix SoC Validation Lab, and vice versa. Further, says Bailey, the development work done by Aptix and Zaiq represents "an endorsement of the standard and the first implementation outside of the pure emulation space. This is not only going to prove SCE-API in the environment it was written for (emulation), but is also moving it into a whole new application space."