Over the past decade, system-on-chip (SoC) designs have evolved to address the ever increasing complexity of applications, fueled by the era of digital convergence. Improvements in process technology have effectively shrunk board-level components so they can be integrated on a single chip. New on-chip communication architectures have been designed to support all inter-component communication in a SoC design. These communication architecture fabrics have a critical impact on the power consumption, performance, cost and design cycle time of modern SoC designs. As application complexity strains the communication backbone of SoC designs, academic and industrial R&D efforts and dollars are increasingly focused on communication architecture design. 

This book is a comprehensive reference on concepts, research and trends in on-chip communication architecture design. It will provide readers with a comprehensive survey, not available elsewhere, of all current standards for on-chip communication architectures.

KEY FEATURES
* A definitive guide to on-chip communication architectures, explaining key concepts, surveying research efforts and predicting future trends
* Detailed analysis of all popular standards for on-chip communication architectures
* Comprehensive survey of all research on communication architectures, covering a wide range of topics relevant to this area, spanning the past several years, and up to date with the most current research efforts
* Future trends that with have a significant impact on research and design of communication architectures over the next several years

On-Chip Communication Architectures: System on Chip Interconnect

3D integration is one of the promising solutions to overcome the interconnect bottleneck with vertical interconnect through-silicon vias (TSVs). This paper investigates the crosstalk in 3D IC designs, especially the capacitive crosstalk in TSV interconnects. We propose a novel ω-LAT coding scheme to reduce the capacitive crosstalk and minimize the power consumption overhead in the TSV array. Combining with the Transition Signaling, the LAT coding scheme restricts the number of transitions in every transmission cycle to minimize the crosstalk and power consumption. Compared to other 3D crosstalk minimization coding schemes, the proposed coding can provide the same delay reduction with more affordable overhead. The performance and power analysis show that when ω is 4, the proposed LAT coding scheme can achieve 38% interconnect crosstalk delay reduction compared to the data transmission without coding. By reducing the value of ω, further reduction can be achieved1.

3DLAT: TSV-based 3D ICs crosstalk minimization utilizing Less Adjacent Transition code

Through silicon vias (TSVs) play an important role as the vertical electrical connections in 3-D stacked integrated circuits. However, the closely clustered TSVs suffer from the crosstalk noise between the neighboring TSVs, and result in the extra delay and the deterioration of signal integrity. For a $3 \times 3$ TSV array, the severity of crosstalk noise in the center victim TSV is classified into 11 levels, which is defined as 0C to 10C from low noise to high noise, depending on the combinations of the digital patterns applied to the TSV array. An enhanced code based on the Fibonacci number system (FNS) to suppress the crosstalk noise below 6C level is proposed, in which both the redundancy of numbers and the nonuniqueness of Fibonacci-based binary codeword are utilized to search the proper codeword. Experimental results show that the proposed technique decreases about 22% latency of TSVs comparing with the worst crosstalk cases. This technique is applicable in the large-scale TSV array for it has a quasi-linear hardware overhead, and its system overhead is less than that of the 3-D 4-LAT counterpart if the data width is greater than 18, and it has good usability for it consumes less power per TSV and achieves lower bit error rate at the interested frequency range comparing with that of the original FNS coding technique.

An Enhancement of Crosstalk Avoidance Code Based on Fibonacci Numeral System for Through Silicon Vias

Bus-invert (BI) coding is the first encoding method for reducing peak and average self-switching power on a bus. It can also reduce capacitive coupling between bus lines. Although it is no longer used as a stand-alone method, it is often used as a starting point for developing a more sophisticated method. Despite its wide use, researchers in the past often resorted to simulations or depended on their intuition to obtain the switching and coupling characteristics. We clearly need a simple but accurate way to carry out this task. We previously published results on BI coding analysis for switching activity reduction. In this paper we conduct a theoretical analysis of BI coding for coupling reduction for uncorrelated uniformly distributed data. Our findings include a set of closed-form formulas for computing the number of couplings per bus transfer for a nonpartitioned versus a partitioned bus. These formulas are simple and easily understandable. They can be readily used for calculating couplings by simply plugging one or two parameter values into them.

Inter-Wire Coupling Reduction Analysis of Bus-Invert Coding

Koc and Sunar proposed an architecture of the Mastrovito multiplier for the irreducible trinomial f(x)=xn+xk+1, where k ≠ n/2 to reduce the time complexity. Also, many multipliers based on the Karatsuba-Ofman algorithm (KOA) was proposed that sacrificed time efficiency for low space complexity. In this paper, a new multiplication formula which is a variant of KOA presented. We also provide a straightforward architecture of a non-pipelined bit-parallel multiplier using the new formula. The proposed multiplier has lower space complexity than and comparable time complexity to previous Mastrovito multipliers' for all irreducible trinomials.

New Bit Parallel Multiplier With Low Space Complexity for All Irreducible Trinomials Over $GF(2^{n})$

Considerable research has been done in the area of bus-encoding techniques, for either power minimization or cross-talk elimination in system-level buses, but not both together. We propose No Adjacent Transition (NAT) coding scheme, a bus encoding technique that simultaneously reduces power consumption and eliminates cross-talk. NAT-encoding and decoding algorithms are proposed and an analytical study of power dissipation is presented.

P. Subrahmanya

Papers

A bus encoding technique for power and cross-talk minimization