Retiming for high-performance superconductive circuits with register energy minimization
Retiming for high-performance superconductive circuits with register energy minimization
复制标题
具有寄存器能量最小化的高性能超导电路的重定时
DOI：
10.1145/3400302.3415659
复制
发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Pedram, Massoud
中科院分区：
文献类型：
--
作者：
Lin, Ting-Ru;Pedram, Massoud
重新定时是一种电路转换，通过重新定位寄存器来优化性能、面积或能耗，在CMOS设计中已经达到了高度成熟的水平。然而，最近非cmos技术的出现和迅速崛起正在引入标准重定时问题的新的和重要的变体。本文提出了一种路径平衡重定时转换方法，以超导设计为例进行评估，重定时方案必须实现电路的全路径平衡，同时最小化具有性能约束的插入寄存器的能量消耗。这个优化问题被称为约束寄存器能量最小化(CREM)问题，它被精确地表示并用多项式求解。接下来，扩展CREM问题公式以在仅需要部分(有界深度差)路径平衡(PPB)特性的双时钟架构下对电路进行重定时。证明了PPB-CREM问题是NP-完全问题。因此，我们提出了一种具有有界误差的多项式时间近似算法来求解这种重定时变量。与以前的工作相比，我们的方法平均减少了14个基准电路38%的寄存器数量和50%的寄存器能耗。此外，我们的近似解与最优解之间的注册能耗竞争比平均仅为1.08。
Retiming, which is a circuit transformation whereby registers are relocated to optimize performance, area, or energy consumption, has reached a high level of maturity in CMOS designs. However, the recent emergence and rapid rise of non-CMOS technologies are introducing new and important variants of the standard retiming problems. This paper presents a path-balancing retiming transformation, taking superconductive designs as an evaluation case study, where the retiming solution must achieve full path balancing of the circuit while simultaneously minimizing the energy consumption of inserted registers with performance constraints. This optimization problem, which is called a constrained register energy minimization (CREM) problem, is precisely formulated and polynomially solved. Next, the CREM problem formulation is extended to retime the circuit under a dual clocking architecture requiring partially (bounded depth difference) path balanced (PPB) characteristics only. It is shown that the PPB-CREM problem is NP-complete. We thus propose a polynomial-time approximation algorithm with a bounded error to solve this retiming variant. Compared to prior work, our approach reduces 38% of register count and 50% of register energy consumption of 14 benchmark circuits on average. Moreover, the competitive ratio of the register energy consumption between our approximate solution and the optimal solution is on average only 1.08.