Bit-Stuffing Algorithms for Crosstalk Avoidance in High-Speed Switching

Abstract

The crosstalk effect is one of the main problems in deep sub-micron designs of high-speed buses. To mitigate the crosstalk effect, there are several types of crosstalk avoidance codes proposed in the literature. In this paper, we are particularly interested in generating forbidden transition codes that do not have opposite transitions on any two adjacent wires. For this, we propose a sequential bit-stuffing algorithm and a parallel bit-stuffing algorithm. For the sequential bit-stuffing algorithm, we perform a worst-case analysis and a probabilistic analysis. We show by both theoretic analysis and simulations that the coding rate of the sequential bit-stuffing encoding scheme is quite close to the Shannon capacity. In particular, for a bus with n = 10 parallel wires, the difference is only 2.2%. Using a Markov chain analysis, we show that the coding rate of the parallel bit-stuffing algorithm is only slightly lower than that of the sequential bit-stuffing algorithm. The implementation complexity of the parallel bit-stuffing algorithm is linear with n. In comparison with the existing forbidden transition codes that use the Fibonacci representation in the literature, our bit-stuffing algorithms not only achieve higher coding rates but also have much lower implementation complexity.

JCI-CAC: An Efficient Crosstalk Avoidance Code Considering Joint Capacitive and Inductive Effects

“…Thus, the implementation of memoryless CACs is simpler [9]. The previous approaches like Forbidden Overlap Code (FOC) [25], Forbidden Transition Code (FTC) [26], Forbidden Pattern Code (FPC) [27] [28] [29] [30] [31] [32], One Lambda Code (OLC) [28] and Improved OLC (IOLC) [10] are memoryless CACs. FPC methods that do not have forbidden transition patterns are also called Forbidden Pattern Free (FPF).…”

UP-Down OLC: New One-Lambda Crosstalk Avoidance Code Design Based on 5-Wire Model

“…Recently, dealing with crosstalk effects has been extensively explored [7]- [15]. We can classify the proposed methods in different levels, physical, level, transistor level, and RTL level.…”

“…As a result, utilizing a suitable numerical system plays a pivotal role in degrading the area occupation, the critical path of the codec modules, and improvement of energy consumption, and can easily decrease the decoder and encoder overheads. The efficient numerical-based CACs can be classified into different groups like Pattern Free (FPF), Forbidden Transition Free (FTF) [11] codes, Forbidden Pattern Free (FPF) [13], [15] codes, Forbidden Overlap Condition (FOC) [10][16] codes and One Lambda Code (OLC) [10][18] based on the transition patterns that they are preventing to occur. FTC, FPF, FOC, and OLC omit the transitions of C 2 , C 2 , C 3 and C 1 , respectively [10].…”

“…FTC, FPF, FOC, and OLC omit the transitions of C 2 , C 2 , C 3 and C 1 , respectively [10]. FPF CACs can be generated by using Fibonacci-based [11][12] and non-Fibonacci-based [15][17] numerical systems. Fibonacci numerical system, Fibo-CAC, is one of the Fibonacci-based numerical systems [11].…”

“…On the basis of disposed eliminated patterns, crosstalk avoidance codings can be divided based on the delay that can be reduced in the coding method. These codes are Forbidden Pattern Condition (FPC) [13] [15] codes, Forbidden Overlap Condition (FOC) [10] [16] codes, Forbidden Transition Condition (FTC) [11] codes and One Lambda Code (OLC) [10] [18]. OLCs are considered as the most effective types among the stated mechanisms.…”