Abstract: For a given channel and a filter having at least one filter tap, a set of at least one weight value is determined for the at least one filter tap according to which at least one weight value substantially minimizes a gradient of a frequency response for the given channel and substantially maximizes energy of the frequency response for the given channel within a predetermined bandwidth.

Abstract: A bus system includes multiple devices and a bus. The bus is connected to each device. Each device may include a type of input/output (I/O) device, such as a random access memory (RAM) or a microprocessor. The bus transfers data between devices. Data of each device may be encoded with a unique orthogonal code. Encoded data of each device may be superimposed onto a bus so as to permit substantially concurrent communication on the bus by each of the devices. Data of each device is decoded by correlating the encoded data with the unique code used to form the encoded data.

Abstract: Methods and apparatuses for affecting the frequency behavior of connections within a printed circuit board or an integrated circuit are disclosed. Some embodiments include a printed circuit board comprising, a plurality of conductive layers each comprising at least one conductive pad, where each conductive pad on the conductive layers includes a vacancy, and an insulating material disposed about the conductive layers such that the vacancies are at least partially filled with the insulating material.

Abstract: A computer program product and method of simulation involve the present computer simulation model of a lossy transmission line. The model uses a hybrid model at each end of the transmission line, each hybrid model coupled to a port of the transmission line. Each hybrid model is coupled to a forward path model and a reverse path model, such that simulated signals pass through the forward path mode enroute from a first hybrid to the second hybrid, and through the reverse path model enroute from the second hybrid to the first hybrid. At each end of the transmission line there is also a reflection model coupling between the reverse path model and the forward path model.

Abstract: A passive coupling structure constructed using printed circuit board traces is used to separate the low and high frequency components of an incoming digital signal. The low and high frequency components of the signal are sent to separate receivers on an integrated circuit. The low frequency receiver may be a conventional level based receiver. The high frequency receiver is a Schmitt-trigger with hysteresis around a DC level or two comparators with separate reference voltages. The outputs of these receivers are combined to produce a receiver output that has increased reliability and noise immunity.

Abstract: One disclosed embodiment may include a method that includes providing a first set S-parameters for a path of a first substrate having a first port and a second port and providing a second set of S-parameters for a path of a second substrate having a first port and a second port. Waveform parameters are measured for an aggregate path that includes the path of the first substrate, the path of the second substrate, and a structure interconnecting the first and second substrates to provide a third set of S-parameters. A fourth set of S-parameters is calculated for the structure interconnecting the first and second substrates based on the first, second, and third sets of S-parameters.

Abstract: A passive coupling structure constructed using printed circuit board traces is used to separate the low and high frequency components of an incoming digital signal. The low and high frequency components of the signal are sent to separate receivers on an integrated circuit. The low frequency receiver may be a conventional level based receiver. The high frequency receiver is a Schmitt-trigger with hysteresis around a DC level or two comparators with separate reference voltages. The outputs of these receivers are combined to produce a receiver output that has increased reliability and noise immunity.

Abstract: A method is provided for evaluating signal deviations in an electronic design (e.g., a package design), including the steps of: formulating one or more signal deviation rules; processing the electronic design to determine whether the signal deviations violate the signal deviation rules; and generating an indicator (e.g., a DRC and/or report) associated with the electronic design to identify violated signal deviation rules. Processing of the electronic design may be scoped according one or a group of signal nets.

Abstract: A system and method can be utilized to determine S-parameters of a network. In one embodiment a system includes an S-parameter calculator that computes the S-parameters of the network based on waveform parameters determined from single port measurements. At least one of the single port measurements corresponds to measurements at one of the plural ports while a matched load is applied to at least another of the plural ports.

Abstract: A method evaluates signal trace discontinuities in an electronic design of the type having one or more traces. The method includes the steps of formulating one or more trace discontinuity rules, processing the electronic design to determine whether the traces violate the trace discontinuity rules, and generating an indicator (e.g., a DRC) associated with the electronic design to identify violated trace discontinuity rules. Each level, each signal net, or a group of signal nets may be evaluated, for example, to ensure compliance with the trace discontinuity rules.

Abstract: A system and method for determining the dielectric properties associated with a substrate. In one embodiment, a network analyzer measures scattering parameters for at least two lines of substantially identical cross-section embedded within the substrate over a specified frequency range. A first engine determines a complex propagation constant based on the scattering parameters and defines the complex propagation constant in terms of an attenuation component and a phase component. A second engine, responsive to the phase component, determines a relative permittivity parameter associated with the substrate over the specified frequency range. A third engine, responsive to the attenuation component and the relative permittivity parameter, performs a least squares analysis to determine a loss tangent parameter associated with the substrate over the specified frequency range.

Abstract: A reference voltage is moved dynamically towards a voltage level of the last received value. The movement takes place over a predetermined fraction of a bit-time. The amount of movement is limited so that successive logical values don't result in an unusable reference voltage level. When the output of a receiver changes, a state machine sequences the selection of analog reference voltage inputs to a multiplexer to move an output reference voltage towards a steady-state signal voltage level for the value that was just received. When the sequence is complete, the state machine keeps the last value selected on the output until the output of the receiver changes value.

Abstract: A reference voltage is moved dynamically towards a voltage level of the last received value. The movement takes place over a predetermined fraction of a bit-time. The amount of movement is limited so that successive logical values don't result in an unusable reference voltage level. When the output of a receiver changes, a state machine sequences the selection of analog reference voltage inputs to a multiplexer to move an output reference voltage towards a steady-state signal voltage level for the value that was just received. When the sequence is complete, the state machine keeps the last value selected on the output until the output of the receiver changes value.

Abstract: A method is provided for evaluating signal deviations in an electronic design (e.g., a package design), including the steps of: formulating one or more signal deviation rules; processing the electronic design to determine whether the signal deviations violate the signal deviation rules; and generating an indicator (e.g., a DRC and/or report) associated with the electronic design to identify violated signal deviation rules. Processing of the electronic design may be scoped according one or a group of signal nets.

Abstract: A computer program product and method of simulation involve the present computer simulation model of a lossy transmission line. The model uses hybrid model at each end of the transmission line, each hybrid model coupled to a port of the transmission line. Each hybrid model is coupled to a forward path model and a reverse path model, such that simulated signals pass through the forward path mode enroute from a first hybrid to the second hybrid, and through the reverse path model enroute from the second hybrid to the first hybrid. At each end of the transmission line there is also a reflection model coupling between the reverse path model and the forward path model.

Abstract: A method evaluates signal trace discontinuities in an electronic design of the type having one or more traces. The method includes the steps of formulating one or more trace discontinuity rules, processing the electronic design to determine whether the traces violate the trace discontinuity rules, and generating an indicator (e.g., a DRC) associated with the electronic design to identify violated trace discontinuity rules. Each level, each signal net, or a group of signal nets may be evaluated, for example, to ensure compliance with the trace discontinuity rules.

Abstract: A six-drop bus has each driver or receiver terminated at the characteristic impedance of Z0. Each driver or receiver is connected to a segment of transmission line with a characteristic impedance of Z0. Three of these segments are connected at a first point. The other three of these segments are connected at a second point. The first and second points are connected by a central transmission line with a characteristic impedance of Z0/3.

Abstract: A four-drop bus has each driver or receiver terminated at the characteristic impedance of Z0. Each driver or receiver is connected to a segment of transmission line with a characteristic impedance of Z0. Two of these segments are connected at a first point. The other two of these segments are connected at a second point. The first and second points are connected by a central transmission line with a characteristic impedance of Z0/2.

Abstract: A passive coupling structure constructed using printed circuit board traces is used to separate the low and high frequency components of an incoming digital signal. The low and high frequency components of the signal are sent to separate receivers on an integrated circuit. The low frequency receiver may be a conventional level based receiver. The high frequency receiver is a Schmitt-trigger with hysteresis around a DC level or two comparators with separate reference voltages. The outputs of these receivers are combined to produce a receiver output that has increased reliability and noise immunity.

Abstract: A passive coupling structure constructed using printed circuit board traces is used to separate the low and high frequency components of an incoming digital signal. The low and high frequency components of the signal are sent to separate receivers on an integrated circuit. The low frequency receiver may be a conventional level based receiver. The high frequency receiver is a Schmitt-trigger with hysteresis around a DC level or two comparators with separate reference voltages. The outputs of these receivers are combined to produce a receiver output that has increased reliability and noise immunity.