Buffer Insertion Method Research Articles

다중 클록 영역의 SoC를 위한 효율적인 버퍼삽입 방식의 CTS에 대한 고려

본 논문에서는 버퍼 삽입 방법에 기반한 다중 클록 영역에서의 클록 트리 합성(clock tree synthesis, CTS) 기법에 대해서 논의한다. CTS를 수행하는데 있어서 준비해야하는 사항들과 실제적인 CTS 수행 방법들에 대해서 세부적인 기술들을 제안한다. 또한 CTS 수행 이후의 후처리 과정에 대해서도 제안한다. 버퍼 삽입 기반의 CTS는 기존에도 사용되는 방법인데 본 논문은 ASIC 및 SoC 상용 작업 현장에서 사용될 수 있는 실전적인 기법들에 대해서 논의하고자 한다. CTS는 사용되는 툴에 매우 의존적인데 본 논문은 Synopsys의 Astro를 대상으로 하였고, 이 툴을 이용하여 CTS를 수행하기 위한 세부적인 기술들에 대해서 이론을 바탕으로 경험적이고 고급적인 기법들을 제안한다. 본 논문을 통해 제안된 기법들은 많은 백앤드(backend) 설계자들에게 좋은 가이드가 될 것으로 기대한다. In this paper, we consider a clock tree synthesis technique (CTS) based on buffer insertion method in the multiple clock domain. We propose some detail techniques about the preparing items and the practical method for implementing CTS. We also propose a post processing after CTS implementation. Until now, the buffer insertion-based CTS technique has been widely used, and this paper discusses especially it's practical technique to be applied in the commercial fields to develop ASIC and SoC. CTS is very dependent on the used tool. We use Astro of Synopsys and propose the empirical and theoretical information of the detail techniques for implementing CTS using this tool. We expect that the proposed technique becomes to be good guidelines to backend designers.

소모전력을 위한 FPGA 알고리즘에 관한 연구

In this paper, we proposed FPGA algorithm for consider the power consumption. Proposed algorithm generated a feasible cluster by circuit partition considering the CLB condition within FPGA. Separated the feasible cluster reduced power consumption using glitch removal method. Glitch removal appled delay buffer insertion method by signal process within the feasible cluster. Also, removal glitch between the feasible clusters by signal process for circuit. The experiments results show reduction in the power consumption by 7.14% comparing with that of [9].

New path balancing algorithm for glitch power reduction

The authors propose an efficient path balancing algorithm to reduce glitch power dissipation in CMOS logic circuits. The proposed algorithm employs gate sizing and buffer insertion methods to achieve path balancing. The gate sizing technique reduces not only glitches, but also the effective capacitance in the circuit. For the paths which remain unbalanced after gate sizing due to the limitation of gate size, buffer insertion is performed. Since the buffer itself consumes power, it is inserted between the gates where power reduction achieved by glitch reduction is larger than the power consumed by the inserted buffer. Determining the location of the inserted buffer is a difficult problem, because the power reduction achieved by an inserted buffer is closely related to the locations of the other inserted buffers. The ILP (integer linear program) has been employed to determine the locations of inserted buffers. The proposed algorithm has been tested on LGSynth91 benchmark circuits. Experimental results show that 61.5% of glitch reduction and 30.4% of power reduction are achieved without increasing the critical path delay.

Efficient algorithm for glitch power reduction

An efficient algorithm is proposed for reducing glitch power dissipation in CMOS logic circuits. The proposed algorithm takes a path balancing approach that is achieved using gate sizing and buffer insertion methods. The gate sizing technique reduces not only glitches but also the effective circuit capacitance. After gate sizing, buffers are inserted into the remaining unbalanced paths which have not been subjected to gate sizing. ILP has been employed to determine the location of inserted buffers. The proposed algorithm has been tested on LGSynth91 benchmark circuits. Experimental results show that 61.5% of glitches are reduced on average.

A joint gate sizing and buffer insertion method for optimizing delay and power in CMOS and BiCMOS combinational logic

This paper presents the first reported joint gate sizing and buffer insertion method for minimizing the delay of power constrained combinational logic networks that can incorporate a mixture of unbuffered and buffered gates (or mixture of CMOS and BiCMOS gates). In the method, buffered gates in a network are decided on by an iterative process that uses a sequence of sizing optimizations where after each sizing optimization an update to the selection of buffered gates is made. In this way, high drive capability buffered (i.e., BiCMOS) gates with sufficiently low fan-out are identified and replaced with a lower power unbuffered (i.e., CMOS) version. As well, the optimality of the final design is assessed based on a lower-bound delay value that is calculated. Experimental results have confirmed the efficiency and utility of the proposed method. In 8-b adder or 8/spl times/8 b multiplier networks, just two iterations are sufficient to achieve a delay that is at worst within 0.6% of its final optimized value and at worst within 10% of the lower-bound value. In the design of BiCMOS networks, it is seen that a speed advantage (at equivalent power) can be systematically achieved by using a mix of CMOS and BiCMOS gates versus using all CMOS or all BiCMOS gates and that this advantage increases with the tightness of the power constraint and with load capacitance.