Clockless IC design using handshake technology

Abstract

Handshake Solutions has developed a complete design flow for the design of clockless circuits based on Handshake Technology, which is an extremely disciplined asynchronous circuit style, based on distributed handshake control rather than a centralized clock. The design flow has been used in the design of dozens of commercial ICs, resulting in more than hundred million of ICs on the market, in areas such as wireless, automotive, and smartcards.The Handshake Technology design flow is targeted at standard-cell based ASIC design, where design teams already have a set of 3 rd party EDA tools up-and-running for design tasks such as logic synthesis, timing analysis, placement and routing, test-pattern generation, simulation, prototyping, etcetera. Such a design environment is extended with a set of complementary and compatible clockless design tools, that include a Design-for-Test solution based on full-scan. Furthermore, no dedicated 'asynchronous' standard cells are needed in the cell library.The biggest challenge in establishing a good connection with 3rd -party EDA tools is that these have typically been developed with a clocked design approach in mind. At least, that is the way these tools will typically have been used. The challenge comes in two forms. The first challenge is the correctness of the integration. Synchronous tools -- like logic optimizers and timing analysis tools -- have to be guided carefully when they handle an asynchronous netlist. The combination feedback loops either have to be hidden, or loops have to be broken explicitly before the tools can be used reliably. After a correct connection has been established, the second challenge relates to optimizing the use of these tools. Especially when it comes to working towards timing goals, synchronous tools tend to require an explicit timing goal, rather than having the capability to just make a circuit fast. Therefore, timing paths have to be made explicit, and realistically fast targets have to be defined and set.In the presentation the issues mentioned above will be discussed in detail and will be illustrated using examples taken from the ARM996HS. This is the Handshake Technology implementation of an ARM9 core, aimed at low power applications, which currently is the lowest-power ARM9 core licensable from ARM.