Incremental Lagrangian Relaxation Based Discrete Gate Sizing and Threshold Voltage Assignment

Timing closure remains one of the most critical challenges of a physical synthesis flow, especially when the design operates under multiple operating conditions. Even if timing is almost closed at the end of the flow, last-mile placement and routing congestion optimizations may introduce new timing violations. Correcting such violations needs minimally disruptive techniques such as threshold voltage reassignment and gate sizing that affect only marginally the placement and routing of the almost finalized design. To this end, we transform a powerful Lagrangian-relaxation-based optimizer, used for global timing optimization early in the design flow, into a practical incremental timing optimizer that corrects small timing violations with fast runtime and without increasing the area/power of the design. The proposed approach was applied to already optimized designs of the ISPD 2013 benchmarks assuming that they experience new timing violations due to local wire rerouting. Experimental results show that in single corner designs, timing is improved by more than 36% on average, using 45% less runtime. Correspondingly, in a multicorner context, timing is improved by 39% when compared to the fully-fledged version of the timing optimizer.

Optimized Lossless Embedded Compression for Mobile Multimedia Applications

Power consumption is a critical design factor in modern mobile chip design, in which the memory system with dynamic random-access memory (DRAM) consumes more than half of the entire system’s power. Without DRAM bandwidth compression, extreme multimedia operations such as 8K high dynamic range (HDR) recording and 8K video conference calling are not possible without sacrificing image quality or trimming because of thermal limitations or battery time sustainability constraints. Since heterogeneous processors are substantially involved in managing various types of fallbacks or software solutions, complicated compression algorithms for high-compression ratios are not actually adaptable owing to timing closure problems or high throughput requirements. In this paper, we propose evaluation metrics to assess lossless embedded compression (LEC) algorithms to reflect realistic design considerations for mobile multimedia scenarios. Furthermore, we introduce an optimized LEC implementation for contemporary multimedia applications in mobile devices based on the proposed metrics. The proposed LEC implementation enhances the compression ratio of LEC algorithms in other commercial application processors for contemporary premium smartphones by up to 9.2% on average, while maintaining the same timing closure condition.

Timing Closure of Memory Partitions for a Lower Nodes Technologies

Metal interconnects are used to make the interconnections between different part of the circuitry to realize any System on Chip (SoC) design. For the advanced process technologies, the metal interconnects affects the performance of the design. For nanometer process technologies, the coupling effect in the interconnect causes crosstalk and noise. These noise and crosstalk must be affect the operating speed of the design. This is most responsible candidate for the timing aspect of the design. Thus, the physical design and verification of the advanced process technologies should be include the effects of noise and crosstalk. If the timing of a design is not verified, then the design may not perform at the desired operating speed. The power and area are the other factors, that also to be consider with timing for a faster design. There will always be a trade-off between these three factors. Static Timing Analysis (STA) is one of the many techniques used by the designers to verify the timing of the design and also for closing the design with respect to timing, which is called as timing closure.

Analysis of Clock trees for optimization through Multi point Clock Tree Synthesis

With rapid development of deep submicron (DSM) VLSI circuits design, building clock tree with minimal insertion delays and minimal skews has turned out to be challenging. In this Paper for a given specified block with a latency of 530 ns it is aimed to achieve a latency of 400ns and achieve optimal power. Here a Clock Tree Synthesis method is used to reduce the latency and obtain the timing closure for the given block. The analysis is made and compared in terms of clock skew and insertion delay by varying the tap points. In this process of achieving the timing closure it is observed power has optimized by selecting the appropriate tap points.

Clock Tree Optimization for Multi-Corner Multi-Mode Timing Closure with Different Design Flows

Clock Tree Optimization for Multi Corner Multi Mode Timing closure is done with Integrated Clock Gating cells. It is power efficient clock tree technique because, it will reduce the switching power usage of clock. It is implemented using integrated clock Gating cells for reducing the switching power caused by clock propagation in the design during Clock Tree Synthesis. The multi mode and multi corner uses integrated clock gating cells to achieve timing and these cells will reduce dynamic power .This technique can be applied to industrial Digital Intellectual Property(DIP). The cells used in the design are fabricated by using 22nm FDSOI process and these cells used as clock pins by Automatic Root Clock Pin (ARCP) in Clock Specification file during clock tree synthesis along with proposed flows for reducing buffer count. The result shows that the number of buffers added in the each stage is reduced by the proposed flow and also we achieve the timing, power and area. In this paper, by using clock tree optimization technique the clock power dissipation in the chip is reduced by Integrated clock gating cells

Accounting for PVT Variations in Design Timing Closure

The On Chip Variation (OCV) refers to changes in the behavior of parameters like process, voltage and temperatures on a chip. In this paper, we go through different approaches followed to compensate for PVT variations on chip during design timing closure. We review the dominant approaches used for accounting such variations. We also review the advantages and disadvantages of these approaches used based on the ease of use, implementation, power, area, and the overheads involved in adopting them.