延迟非敏感系统的模块化时序约束
Modular Timing Constraints for Delay-Insensitive Systems
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摘要: 本文介绍针对异步系统的专用工具ARCtimer。这种工具可以为自定时握手元件建模、生成并检测时序约束,而后将此约束应用于此元件,确保了元件的门级实现严格遵守其握手协议。因为握手协议抽象地定义出信号时序,具有延迟非敏感特征,而且ARCtimer验证过的自定时元件构成的系统也能够保证延迟非敏感,这种对局部时间的斟酌,可以令设计者在全局上——恰如同步设计(时钟电路)一样——忽略时间延迟。在设计的前期阶段,ARCtimer验证各类握手元件,组成元件库。元件库包含了静态时间分析(STA)代码,以方便对使用元件库的自定时系统进行验证。元件库的描述包含了握手元件电路、协议、时序约束和静态时间分析几个部分,即使在后期使用工艺映射工具和布局布线工具对电路修改,这些描述也具备健壮性特点。此篇论文除提供丰富的相关工作简介与对比之外,也详尽地介绍了我们的创新工作,包括关键的策略、模块化时序验证及其机制。Abstract: This paper introduces ARCtimer, a framework for modeling, generating, verifying, and enforcing timing constraints for individual self-timed handshake components. The constraints guarantee that the component's gate-level circuit implementation obeys the component's handshake protocol specification. Because the handshake protocols are delay insensitive, self-timed systems built using ARCtimer-verified components are also delay-insensitive. By carefully considering time locally, we can ignore time globally. ARCtimer comes early in the design process as part of building a library of verified components for later system use. The library also stores static timing analysis (STA) code to validate and enforce the component's constraints in any self-timed system built using the library. The library descriptions of a handshake component's circuit, protocol, timing constraints, and STA code are robust to circuit modifications applied later in the design process by technology mapping or layout tools. In addition to presenting new work and discussing related work, this paper identifies critical choices and explains what modular timing verification entails and how it works.