魚骨:無時脈高能源效率堆疊

Abstract

低耗電的設計在現在以及未來都是設計的主要方針，尤其在不失速度效能的前提下，低耗電的設計更獨具其優勢。過去有些追求速度效能的研究設計，但是其能源消耗都不盡理想。在此論文中，我們提出一個無時脈高能源效率的堆疊設計以及實作。基於GasP的設計模組概念作延伸，利用主從暫存概念，以及增加暫存，盡可能減少資料在堆疊內部裡的搬運次數來減低能源的消耗。和[1]的設計方法比較，在42個一位元儲存空間的堆疊實驗中，於HSPICE在速度2 GHz下以UMC 0.18製程模擬結果指出，根據不同的輸入命令序列其平均耗電量可以省電達該設計約百分之十七。然而與線性堆疊比較下，實驗之平均耗電量魚骨堆疊更只有其設計之百分之八點三左右。魚骨堆疊的每個堆疊動作的執行時間和儲存空間、資料的長度及命名序列長度沒有關係，其時間是固定的，而其能源消耗則和堆疊命令序列有絕對的相關性。

Low-power circuit design is the fashion of the future design guideline, especially not losing the speed performance. So far some research on stack is performed. However, their power performances are not good enough. The purpose of this paper is to present a power-efficient stack with clock-less design technique and its implementation. Based on GasP asynchronous control family from Sun Microsystems laboratories, we reduced the data movements in stack with the concept of master-slave temporal storages and n-place linear storages to low down the power consumption. For the ease of comparing with other targets in experiment, we implemented our stack with the same number of storages as the target’s one. Results from HSPICE simulations with UMC 0.18 model file show that our stack saved averagely 17% in power consumption with 100 random command sequences that are sized 100 compared to the re-implementation of original design in [1]. More than that, we gained averagely 91.39% in power consumption compared to linear stack. The cycle time is independent of the number of data items in the stack and the data width. It has constant time property. The energy consumption per stack operation depends on the sequence of stack operations.