Single-edge Triggered Flip-flops Research Articles

Design and Analysis of FS-TSPC-DET Flip-Flop for IoT Applications

The paper outlines the utmost importance of energy-efficient devices for IoT applications and recommends adual edge-triggeredTSPC flip-flop in fully-static mode at 45nm technology with low supply rail carried out in CMOS using MENTOR GRAPHICS tool.The proposed flip-flop proved to be energy efficient compared to traditional double and single edge-triggered flip-flops in terms of latency, power, the figure of merit and area for IoT applications. A comparison of two types of dual-edge triggered flip-flops are analyzed concerning the mentioned performance metrics and deduces the best flip-flop for IoT applications. Clock overlap issues are turning down in dual edge-triggered TSPC flip-flopcompared with a conventional dual edge-triggered flip-flop in full static modeand allow stringent operation at 1V supply rail thatdelivers1.14uW power, 0.60fJ figure of merit and 531.99ps latency at 45nm CMOS.

Design and Analysis of FS-TSPC-DET Flip-Flop for IoT Applications

The paper outlines the utmost importance of energy-efficient devices for IoT applications and recommends adual edge-triggeredTSPC flip-flop in fully-static mode at 45nm technology with low supply rail carried out in CMOS using MENTOR GRAPHICS tool.The proposed flip-flop proved to be energy efficient compared to traditional double and single edge-triggered flip-flops in terms of latency, power, the figure of merit and area for IoT applications. A comparison of two types of dual-edge triggered flip-flops are analyzed concerning the mentioned performance metrics and deduces the best flip-flop for IoT applications. Clock overlap issues are turning down in dual edge-triggered TSPC flip-flopcompared with a conventional dual edge-triggered flip-flop in full static modeand allow stringent operation at 1V supply rail thatdelivers1.14uW power, 0.60fJ figure of merit and 531.99ps latency at 45nm CMOS

Variations in Nanometer CMOS Flip-Flops: Part I—Impact of Process Variations on Timing

In this paper, split into Part I and II, the impact of variations on single-edge triggered flip-flops (FFs) is comparatively evaluated across a wide range of state-of-the-art topologies. The analysis explicitly considers fundamental sources of variations such as process/voltage/temperature (PVT), as well as the clock network (clock slope variations). For each topology, the variations of performance, robustness against hold violations, energy and leakage are statistically evaluated and compared. The impact of layout parasitics is explicitly included in the circuit design loop. The presented results provide well-defined guidelines for variation-aware selection of the flip-flop topologies, and estimates for early budgeting of variations before detailed circuit design. Also, the analysis enables a deeper understanding of the sensitivity to variations of existing topologies across a wide range of sizes and loads. In particular, this Part I introduces the methodology, the targeted flip-flop topologies and investigates the impact of process variations on flip-flop timing.

Variations in Nanometer CMOS Flip-Flops: Part II—Energy Variability and Impact of Other Sources of Variations

In this paper, the impact of variations on single-edge triggered flip-flops (FFs) is evaluated for a wide range of topologies. In particular, this Part II explicitly considers sources of variations such as voltage, temperature and variations induced by the clock network. The effect of variations on the energy and its tradeoff with performance is also investigated. This paper complements the previous Part I, which is focused on process variations and flip-flop timing. From a design perspective, the presented results provide well-defined guidelines for variation-aware selection of the flip-flop topologies, and for early budgeting of variations before detailed circuit design. Results are put into the technology scaling perspective through comparison of results at 65 and 28 nm. The results show that the technology scaling does not affect either the main findings of this analysis or the ranking of the considered topologies.

Design of a High Performance Dual Edge-Triggered Flip-Flop for Low Power Circuit

이중 에지 트리거 플립플롭 (dual edge-triggered flip flop)은 클록의 하향에지 (negative edge) 뿐만 아니라 상향에지 (positive edge)에서 데이터를 샘플링 (sampling)하는 순차회로 요소이다. 이중 에지 트리거 플립플롭은 클록 주파수의 오직 반주기에서 동작하는 동안 변함없는 처리량 (throughput)이 유지한다는 장점을 갖는다. 본 논문에서는 저전력 회로에 적용이 가능한 이중 에지 트리거 플립플롭을 제안하고 특성을 비교하였으며, 1.8V의 공급전압과 0.18um CMOS 공정 기술을 사용하여 설계하였다. 제안한 회로는 기존 연구에 비해 18.1%의 전력소비를 절감하였으며, 16.1%의 전력소비와 지연시간의 곱 (power-delay-product, PDP) 특성을 개선하였다. 제안한 회로는 HSPICE 시뮬레이션을 통하여 타당성을 입증하였다.

Asynchronous Data Sampling Within Clock-Gated Double Edge-Triggered Flip-Flops

For synchronous designs, a large portion of the total power consumption of the integrated circuit (IC) is due to the storage elements and the clock distribution. Energy efficiency from the clock elements plays a critical role in low-power circuit design. One technique for efficiency is the use of double edge-triggered flip-flops (DETFFs), since they can maintain the same throughput as single edge-triggered flip-flops (SETFFs) while only using half of the clock frequency. Clock gating is another well-accepted technique to reduce the dynamic power of idle modules or idle cycles. However, incorporating clock gating with DETFFs to further reduce dynamic power consumption introduces an asynchronous data sampling (i.e., a change in output between clock edges) that was not addressed in previous research. This asynchronous data sampling is explored in detail in this paper by analyzing the mechanisms of several different clock-gated DETFFs. Three special clock-gating strategies are evaluated to mitigate this issue in DETFFs. Each of these three solutions has limitations, and the respective tradeoffs are discussed.

Low Power Dual Edge - Triggered Static D Flip-Flop

This paper enumerates new architecture of low power dual-edge triggered Flip-Flop (DETFF) designed at 180nm CMOS technology. In DETFF same data throughput can be achieved with half of the clock frequency as compared to single edge triggered Flip-Flop (SETFF). In this paper conventional and proposed DETFF are presented and compared at same simulation conditions. The post layout experimental results comparison shows that the average power dissipation is improved by 48.17%, 41.29% and 36.84% when compared with SCDFF, DEPFF and SEDNIFF respectively and improvement in PDP is 42.44%, 33.88% and 24.69% as compared to SCDFF, DEPFF and SEDNIFF respectively. Therefore the proposed DETFF design is suitable for low power and small area applications.

Low-power∕high-performance explicit-pulsed flip-flop using static latch and dynamic pulse generator

Latches and flip-flops play important roles in the building of digital CMOS circuits. In the paper, a new low-power positive level-sensitive latch and a simple and innovative dynamic pulse generator are proposed. The pulse generator is then used with the proposed latch to create a low-power and high-performance single edge-triggered flip-flop (SETFF). The proposed positive level-sensitive latch deploys two non-precharge (static) n-stages (SN) in a true-single-phase-clocking (TSPC) scheme. We therefore named our latch SN2. This is because the TSPC latches have the advantage of single clock distribution, less clock routing area, high-speed and no clock skew. Based on the 0.18-μm single-poly six-metal CMOS technology, the SPECTRE simulation results derived for typical input activities showed that the latch can attain a maximum power saving of 29.1% when compared to other reported designs. As for our proposed flip-flop that is derived from the proposed SN2 latch with incorporation of a dynamic pulse generator circuit, it is able to outperform other reported works by about 16.2% to 67.4% for its power-delay product (PDPCQ) that is taken with respect to the clock-to-output delay. The two new designs are therefore suitable for used in low-power and high-performance CMOS VLSI/ULSI applications.

Analysis of power dissipation in double edge-triggered flip-flops

A comprehensive analysis of double edge triggered (DET) flip-flops' power dissipation, taking into account input signal statistics, is presented in this paper. It is shown that using DET instead of a single edge-triggered flip-flop may result in significant energy savings if the input signal has reduced activity. On the other hand, the high switching rate of DET internal nodes may result in larger power dissipation if the input signal has a high transition probability or significant glitching.

High performance double edge-triggered flip-flop using a merged feedback technique

Double edge-triggered flip-flops (DETFFs) use both edges of the clock to latch data and hence can lead to significant power saving over single edge-triggered flip-flops for a fixed data rate. However, existing DETFF implementations suffer from the problems of charge sharing, charge coupling, incomplete voltage swing, poor voltage scaling properties and excessive power dissipation. A new DETFF is proposed, which does not suffer from any of these problems and can operate at a clock speed which is 1.33 times that of the best double edge-triggered flip-flop available today. With reduced supply voltages, this flip-flop results in lower power dissipation and maintains a comparable performance to, if not better than, existing DETFFs.

Reduced implementation of D-type DET flip-flops

One of the main disadvantages of using D-type double-edge triggered flip-flops (DET-FFs) in VLSI system design is the number of transistors required. Two new DET-FF circuits (one static, the other dynamic) are proposed in which the number of transistors is reduced to a number similar to that for classic single-edge triggered flip-flops (SET-FFs). Both new circuits not only behave correctly when operated at high frequency but also offer a good level of immunity to metastability problems (static) and race problems (dynamic), as well as presenting a simple straightforward layout. These considerations offer wider practical and economic applications for the use of DET-FFs in VLSI system design.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>