A novel double edge-triggered pulse-clocked TSPC D flip-flop for high-performance and low-power VLSI design applications

Clocking is an important aspect of digital VLSI system design. The design of high-performance and low-power clocked storage elements is essential and critical to achieving maximum levels of performance and reliability in modern VLSI systems such as Systems on Chips (SoCs). In this thesis, a pulse-clocked double edge-triggered D-flip-flop (PDET) is proposed. PDET uses a new split-output true single-phase clocked (TSPC) latch and when clocked by a short pulse train acts like a double edge-triggered flip-flop. The P-type version of the new TSPC split-output latch is compared with existing TSPC split-output latches in terms of robustness, area, and power efficiency at high-speeds. It is shown that the new split-output latch is more area-power efficient, and significantly more robust, than the existing split-output CMOS latches. The novel double edge-triggered flip-flop uses only eight transistors with only one N-type transistor being clocked. Compared to other double edge-triggered flip-flops, PDET offers advantages in terms of speed, power, and area. Both total transistor count and the number of clocked transistors are significantly reduced to improve power consumption and speed in the flip-flop. The number of transistors is reduced by 56%-60% and the Area-Period-Power product is reduced by 56%-63% compared to other double edge-triggered flip-flops. Simulations are performed using HSPICE in CMOS 0.5 om technology. This design is suitable for high-speed, low-power CMOS VLSI design applications

Automated performance evaluation of skew-tolerant clocking schemes

In this paper the authors evaluate the timing and power performance of three skew-tolerant clocking schemes. These schemes are the well known master–slave clocking scheme (MS) and two schemes developed by the authors: Parallel alternating latches clocking scheme (PALACS) and four-phase parallel alternating latches clocking scheme (four-phase PALACS). In order to evaluate the timing performance, the authors introduce algorithms to obtain the clock waveforms required by a synchronous sequential circuit. Separated algorithms were developed for every clocking scheme. From these waveforms it is possible to get parameters such as the non-overlapping time and the clock period. They have been implemented in a tool and have been used to compare the timing performance of the clocking schemes applied to a simple circuit. To analyse the power consumption the authors have electrically simulated a simple circuit for several operation frequencies. The most remarkable conclusion is that it is possible to save about 50% of the power consumption of the clock distribution network by using PALACS.Ministerio de Ciencia y Tecnología TEC 2004-00840/MI

Bridging the Testing Speed Gap: Design for Delay Testability

The economic testing of high-speed digital ICs is becoming increasingly problematic. Even advanced, expensive testers are not always capable of testing these ICs because of their high-speed limitations. This paper focuses on a design for delay testability technique such that high-speed ICs can be tested using inexpensive, low-speed ATE. Also extensions for possible full BIST of delay faults are addresse

Single-Event Upset Analysis and Protection in High Speed Circuits

The effect of single-event transients (SETs) (at a combinational node of a design) on the system reliability is becoming a big concern for ICs manufactured using advanced technologies. An SET at a node of combinational part may cause a transient pulse at the input of a flip-flop and consequently is latched in the flip-flop and generates a soft-error. When an SET conjoined with a transition at a node along a critical path of the combinational part of a design, a transient delay fault may occur at the input of a flip-flop. On the other hand, increasing pipeline depth and using low power techniques such as multi-level power supply, and multi-threshold transistor convert almost all paths in a circuit to critical ones. Thus, studying the behavior of the SET in these kinds of circuits needs special attention. This paper studies the dynamic behavior of a circuit with massive critical paths in the presence of an SET. We also propose a novel flip-flop architecture to mitigate the effects of such SETs in combinational circuits. Furthermore, the proposed architecture can tolerant a single event upset (SEU) caused by particle strike on the internal nodes of a flip-flo

A low-speed BIST framework for high-performance circuit testing

Testing of high performance integrated circuits is becoming increasingly a challenging task owing to high clock frequencies. Often testers are not able to test such devices due to their limited high frequency capabilities. In this article we outline a design-for-test methodology such that high performance devices can be tested on relatively low performance testers. In addition, a BIST framework is discussed based on this methodology. Various implementation aspects of this technique are also addresse

Desynchronization: Synthesis of asynchronous circuits from synchronous specifications

Asynchronous implementation techniques, which measure logic delays at run time and activate registers accordingly, are inherently more robust than their synchronous counterparts, which estimate worst-case delays at design time, and constrain the clock cycle accordingly. De-synchronization is a new paradigm to automate the design of asynchronous circuits from synchronous specifications, thus permitting widespread adoption of asynchronicity, without requiring special design skills or tools. In this paper, we first of all study different protocols for de-synchronization and formally prove their correctness, using techniques originally developed for distributed deployment of synchronous language specifications. We also provide a taxonomy of existing protocols for asynchronous latch controllers, covering in particular the four-phase handshake protocols devised in the literature for micro-pipelines. We then propose a new controller which exhibits provably maximal concurrency, and analyze the performance of desynchronized circuits with respect to the original synchronous optimized implementation. We finally prove the feasibility and effectiveness of our approach, by showing its application to a set of real designs, including a complete implementation of the DLX microprocessor architectur

High speed CMOS/SOS standard cell notebook

The NASA/MSFC high speed CMOS/SOS standard cell family, designed to be compatible with the PR2D (Place, Route in 2-Dimensions) automatic layout program, is described. Standard cell data sheets show the logic diagram, the schematic, the truth table, and propagation delays for each logic cell