The Effects of Interconnections on High-Speed Logic Circuits
TL;DR: It is shown that high-speed circuitry must be miniaturized and the implications are discussed.
Abstract: By way of worked examples in typical but somewhat idealized cases the effect on circuit speed of circuit interconnections is studied. The source, calculation and minimization of interconnection crosstalk is also discussed. It is shown that high-speed circuitry must be miniaturized and the implications are discussed.
Citations
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TL;DR: Methods are presented in this paper to characterize the deterministic and crosstalk-induced jitter from measurements of total jitter and an improved tail-fit deconvolution method is proposed for characterizing the impact of deterministic jitter in the presence of random jitter.
Abstract: A small amount of jitter can quickly eat up timing budgets and create timing issues. Precise characterization of deterministic and crosstalk-induced jitter can help isolate and solve issues within high-speed links. Characterizing deterministic and crosstalk-induced jitter is challenging, however, because many types of jitter work together to create the overall jitter profile. Methods are presented in this paper to characterize the deterministic and crosstalk-induced jitter from measurements of total jitter. An improved tail-fit deconvolution method is proposed for characterizing the impact of deterministic jitter in the presence of random jitter. The contribution of random jitter to total jitter is found first, and then that contribution is accounted for to find deterministic jitter. A Wiener filter deconvolution method is also presented for extracting the characteristics of crosstalk-induced jitter from measurements of total jitter made when the crosstalk sources were and were not present. The Wiener filter allows for accurate deconvolution of the measured histograms for total jitter even in the presence of the measurement noise. The proposed techniques are shown to work well both in simulations and in measurements of a high-speed link.
10 citations
01 Jun 1988
TL;DR: Techniques are described for simulating lossy (RLC) transmission lines based on the method of characteristics and a method is presented which speeds up the simulation time by a factor of two compared with existing techniques.
Abstract: This paper describes new techniques for simulating lossy (RLC) transmission lines based on the method of characteristics. For uncoupled lossy transmission lines a method is presented which speeds up the simulation time by a factor of two compared with existing techniques. A method is also presented for the transient analysis of coupled lossy lines in an inhomogeneous medium. Previously, simulation techniques were limited to coupled lossy lines in a homogeneous medium.
9 citations
03 Sep 2008
TL;DR: A new type of pseudo-differential link is introduced in which the interconnection comprises a return conductor wider than the transmission conductors, whereas conventional pseudo- differential links use a common conductor similar to the transmission Conductors.
Abstract: This paper introduces a new type of pseudo-differential link in which the interconnection comprises a return conductor wider than the transmission conductors, whereas conventional pseudo-differential links use a common conductor similar to the transmission conductors. We explain the principle of this signaling scheme, referred to as the ZXnoise method, and the particular properties expected from the p.u.l. impedance and admittance matrices of the interconnection. The essential feature of the ZXnoise method is that it may provide low reflections and a good protection against external crosstalk, because the return conductor in a way acts as an electromagnetic screen, which shields the transmission conductors from ground.
9 citations
Cites background from "The Effects of Interconnections on ..."
...Consequently, substantial reflections of signals occur, and this implies limitations on the length L of the interconnection (L must be sufficiently small) and on the available bandwidth, since the limitation stated by Jarvis [5] applies (L should typically be less than one fourth of the distance traveled during the transition time)....
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TL;DR: A new method for the reduction of crosstalk and echo is defined, which involves specific terminations, specific transmitting circuits to send signals, and specific receiving circuits to receive signals and compares it with a different concept based on modal variables and unspecified terminations.
Abstract: Crosstalk and echo can be reduced in multiconductor interconnections, using (truly) matched terminations and a different modal variable for each transmission channel. We first study a conventional technique for reducing reflections, using grounded linear two-terminal circuit elements. Using the concepts of modal voltages and modal currents, we define a new method for the reduction of crosstalk and echo, which involves specific terminations, specific transmitting circuits to send signals, and specific receiving circuits to receive signals. We establish the design equations and show that the new method is related to a particular choice of eigenvectors, called associated eigenvectors. Simulations of two examples of implementation of this method confirm that it provides reduced crosstalk and echo. We also discuss the implementation of the new method with an interconnection having identical propagation constants for all modes. Finally, we compare the new method with a different concept based on modal variables and unspecified terminations.
8 citations
Cites background from "The Effects of Interconnections on ..."
...The computed crosstalk coupling factor is independent of frequency and near dB, and the voltages are in phase with V21....
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01 Jul 2018
TL;DR: This paper re-define the far-end crosstalk (FEXT) as a combination of several components generated by different coupling and reflection mechanisms, and a new set of crosStalk estimation formulas is developed to calculate the contribution of each component.
Abstract: The analytical formulas for crosstalk due to backward and forward coupling were originally introduced in 1963 [1]. In 2016, the formulas were extended for asymmetrical traces [2]. But all previous approaches assume perfectly-matched terminals, which limits the usage of these equations. In this paper, we re-define the far-end crosstalk (FEXT) as a combination of several components generated by different coupling and reflection mechanisms. A new set of crosstalk estimation formulas is developed to calculate the contribution of each component. Because the influence of mismatched terminals is introduced, the proposed method has much better accuracy than the traditional approach, which estimates FEXT by using forward coupling noise alone. In addition, the proposed equations use per-unit-length inductance (L) and capacitance (C) metrics as inputs instead of S-parameters. Since L and C can be calculated using analytical formulas, the new approach provides a practical and fast crosstalk estimation for engineering designs, avoiding the time-consuming numerical full wave 2D or 3D simulations.
8 citations
Cites background from "The Effects of Interconnections on ..."
...Jarvis analyzed backward and forward coupling between two symmetrical and lossless transmission lines with perfectly-matched terminals, and gave analytical formulas to estimate crosstalk caused by a pulse with finite rise time [1]....
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...Abstract—The analytical formulas for crosstalk due to backward and forward coupling were originally introduced in 1963 [1]....
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References
More filters
01 Nov 1954
TL;DR: In this article, a simple configuration of four wires (or two wires and ground) can serve simultaneously as a directional coupler, filter, and transformer, and the coupled lines may be of equal or different impedance.
Abstract: The natural coupling between parallel transmission lines is inherently directional. Very simple and cheap directional couplers can be made which utilize this effect. By introducing appropriate variation of coupling with distance a wide variety of transmission characteristics may be realized, including high-pass (ideally, infinite bandwidth) characteristics. The coupled lines may be of equal or different impedance. Thus, a simple configuration of four wires (or two wires and ground) can serve simultaneously as a directional coupler, filter, and transformer.
215 citations
IBM1
TL;DR: This computer, like the 704, is aimed at scientific problems such as reactor design, hydrodynamics problems, partial differential equations etc., its instruction set and organization are such that it can handle with ease data-processing problems normally associated with commercial applications, such as processing of alphanumeric fields, sorting, and decimal arithmetic.
Abstract: The Stretch Computer project was started in order to achieve two orders of magnitude of improvement in performance over the then existing 704. Although this computer, like the 704, is aimed at scientific problems such as reactor design, hydrodynamics problems, partial differential equations etc., its instruction set and organization are such that it can handle with ease data-processing problems normally associated with commercial applications, such as processing of alphanumeric fields, sorting, and decimal arithmetic.
76 citations
[...]
TL;DR: This paper gives a brief description of work originating in the Computer Group at Manchester University, the name given to a large computing system which can include a variety of peripheral equipments, and an extensive store.
Abstract: This paper gives a brief description of work originating in the Computer Group at Manchester University. Atlas is the name given to a large computing system which can include a variety of peripheral equipments, and an extensive store. All the activities of the system are controlled by a program called the supervisor. Several types of store are used, and the addressing system enables a virtually unlimited amount of each to be included. The primary store consists of magnetic cores with a cycle time of under two microseconds, which is effectively reduced by multiple selection mechanisms. The core store is divided into 512 word "pages"; this is also the size of the fixed blocks on drums and magnetic tapes. The core store and drum store are addressed identically, and drum transfers are performed automatically as described in Section 3. There is a fixed store which consists of a wire mesh into which ferrite slugs are inserted; it has a fast read-out time, and is used to hold common routines including routines of the supervisor. A subsidiary core store is used as working space for the supervisor. The V-store is a collective name given to various flip-flops throughout the computer, which can be read, set, and re-set by reading from or writing to particular store addresses.
28 citations
Book•
[...]
01 Nov 2001
TL;DR: In this article, a brief description of work originating in the Computer Group at Manchester University is given, where the core store is divided into 512 word "pages"; this is also the size of the fixed blocks on drums and magnetic tapes.
Abstract: This paper gives a brief description of work originating in the Computer Group at Manchester University. Atlas is the name given to a large computing system which can include a variety of peripheral equipments, and an extensive store. All the activities of the system are controlled by a program called the supervisor. Several types of store are used, and the addressing system enables a virtually unlimited amount of each to be included. The primary store consists of magnetic cores with a cycle time of under two microseconds, which is effectively reduced by multiple selection mechanisms. The core store is divided into 512 word "pages"; this is also the size of the fixed blocks on drums and magnetic tapes. The core store and drum store are addressed identically, and drum transfers are performed automatically as described in Section 3. There is a fixed store which consists of a wire mesh into which ferrite slugs are inserted; it has a fast read-out time, and is used to hold common routines including routines of the supervisor. A subsidiary core store is used as working space for the supervisor. The V-store is a collective name given to various flip-flops throughout the computer, which can be read, set, and re-set by reading from or writing to particular store addresses.
27 citations
01 Jan 1960
18 citations