International Business Machines Corporation

Daimler Chrysler Ag

Other

Daimler Ag

Mercedes-benz Aktiengesellschaft

Cts Farhrzeug-dachsystems Gmbh

Michael V Koch

Matthias Ringe

Fatih Cilek

Andreas H A Arp

Andreas Arp

Thomas Makowski

Guenther Hutzl

Andre Hertwig

Douglas J Malone

Juergen Schrader

Christian I Menolfi

Dieter Nissler

Ferdinand Greiner

Florian Braun

Stefan Orth

Ludwig Emmer

Thomas Baessler

Corinna Fuchs

Ulrich Bauer

Tilo Steinborn

A burn-in resilient integrated circuit is provided. The burn-in resilient integrated circuit includes an inverter chain and a plurality of inverter circuits on the inverter chain. The burn-in resilient integrated circuit also includes a loop providing an electrical connection from an output of the inverter chain to an input of the inverter chain. The loop is selectable in accordance with a burn-in operation.

Burn-in resilient integrated circuit for processors

Measuring a control system response time of a second clock tree is provided, comprising measuring a skew between the second clock signal and the first clock signal and storing the skew, initiating a delay change of a delay induced by the programmable delay line and starting a time measurement. At least one iteration is performed of measuring the skew between the second clock signal and the first clock signal and comparing the measured skew with the stored skew. Based on the result of the comparison, stopping after a current iteration and stopping the time measurement. A result of the time measurement is the control system response time.

Measuring a control system response time

Disclosed aspects relate to a clock distribution network of a synchronous logic device. The synchronous logic device has sub-circuits having different clock domains. The clock domains form a hierarchical structure. The clock distribution network has a clock source to provide a global clock signal. A programmable delay line associated with a sub-circuit generates a local clock signal for the sub-circuit by delaying the signal. A global skew control circuit can manage clock skew between the local clock signals. The global skew control circuit may adjust a delay, determine initial operations for the delay lines, verify whether it is possible to perform the initial operations, and perform a correction operation. The correction operation can include correcting the control commands such that the corrected commands lead to the same change of skew adjustment between the local clocks.

Integrated skew control

A skew sensor for detecting skew between two input signals is provided. The skew sensor includes at least two skew detectors. The first skew detector receives either a first clock signal or a second clock signal as a first input signal, and the other one of the first clock signal and the second clock signal delayed by a first delay difference induced by one or more delay elements as a second input signal. The second skew detector receives either the first clock signal or the second clock signal as the first input signal, and the other one of the first clock signal and the second clock signal optionally delayed by a second delay difference induced by one more delay elements, wherein the second delay difference is different from the first delay difference, as the second input signal. Skew is measured between the first clock signal and the second clock signal.

Quantitative skew sensor

Embodiments are disclosed for routing a cell of a semiconductor chip, the cell being represented by a matrix, encoding first tracks of the cell as columns of the matrix and second tracks of the cell as rows of the matrix, respectively. The method includes performing a sweep operation on the matrix, the sweep operation including generating an index structure indexed by columns of the matrix, the index structure including information on candidate cut shapes that can be placed in a particular column of the matrix. Additionally, the method includes recursively placing cut shapes into the cell based on the index structure, one recursion of the placing including finding a possible cut shape and recursively placing the remaining cut shapes.

Routing a cell of a semiconductor chip

A computer system improves a production yield of a semiconductor chip described by design data. The computer system includes a synthesis controller in signal communication with a yield optimization controller. The synthesis controller generates design data representing a design implementation of the semiconductor chip. The yield optimization controller extracts timing information from the design data. The timing information describes a slack related to a timing path within the semiconductor chip. The yield optimization controller further identifies one or more one yield improvable cells described by the design data, and determines from the design data an adverse impact of yield improvement on the slack. Based on the timing information and the determined adverse impact, the yield optimization controller calculates a subset of the yield improvable cell, and modifies the subset of the yield improvable cell so that the production yield is improved.

Yield improving leaf cells optimization for semiconductor netlists

An integrated circuit is provided. The integrated circuit includes a plurality of skitter circuits and a multiplexer that provides the waveform to the plurality of skitter circuits. The plurality of skitter circuits includes at least a first skitter circuit and a second skitter circuit. The first and second skitter circuits are arranged in parallel with respect to an output of the multiplexer. The first skitter circuit can include a first data path and a plurality of first inverters on that first data path. Further, the second skitter circuit can include a second data path, a plurality of second inverters on the second data path, and a delay element connected in series with an input of an initial inverter of the plurality of the second inverters on the second data path.

Calibrating internal pulses in an integrated circuit

A method for cycle accurate deskewing a second clock signal with respect to a first clock signal is provided. The first clock signal has been propagated from a first clock source through a first clock tree. The second clock signal has been propagated from the first clock source through a second clock tree. The second clock tree comprises a programmable delay line for inducing a delay. The method comprises determining a first clock tree latency of the first clock tree, determining a second clock tree latency of the second clock tree, setting a cycle time of the first clock source to a measuring cycle time depending on the first clock tree latency and/or the second clock tree latency, adjusting a skew between the second clock signal and the first clock signal, setting the cycle time of the first clock source to an operating cycle time.

Cycle accurate skew adjust

A method for adjusting a skew between a second clock signal and a first clock signal is provided. The second clock signal has been propagated from a first clock source through a second clock tree. The second clock tree comprises a programmable delay line that induces a delay. The method comprises at least one iteration of: measuring a skew between the second clock signal and the first clock signal, comparing an absolute difference of the measured skew and a sum of delay changes initiated in a time window preceding the measurement with a target skew, and initiating a delay change of the delay induced by the programmable delay line in the second clock tree depending on a result of the comparison.

Continuous skew adjust

According to one or more embodiments of the present invention, a computer-implemented method includes determining, for a first sector from multiple sectors of a clock mesh of a semiconductor circuit, a set of mesh wires. The method further includes generating tapping point candidates, selecting a first combination of tapping points, and performing an analog electrical simulation of a clock signal. The simulation includes feeding the clock signal into the clock mesh via the first combination of tapping points via a clock signal transmitter, and measuring delays for the clock signal to reach a set of measuring nodes. The maximum delay from the measured delays is selected, and, in response to the maximum delay being less than a previous delay value, the first combination of tapping points is used to connect sector buffers from the first sector to the clock mesh.

Optimally driving non-uniform clock mesh loads

Duty cycle correction devices for static compensation of an active clock edge shift. A duty cycle correction circuit in the duty cycle correction device corrects a clock input signal, according to a first control signal. A programmable delay circuit or a modified duty cycle correction circuit in the duty cycle correction device compensates a shift of an active clock edge in a clock output signal of the duty cycle correction circuit, according to a second control signal. A mapping circuit in the duty cycle correction device generates the second control signal by mapping a digital value of the first control signal and a digital value of the second control signal.

Static compensation of an active clock edge shift for a duty cycle correction circuit

The present invention provides a system and method of correcting duty cycle (DC) and compensating for active clock edge shift. In an embodiment, the system includes at least one control circuit to receive DCC control signals and to output at least one first adjustment signal, at least one second adjustment signal, at least one first correction signal, and at least one second correction signal, at least one adjustment circuit to change a DC value of an input clock signal, at least one correction circuit to compensate for a shift of an active clock edge of the input clock signal, and where one of the at least one adjustment circuit and the at least one correction circuit is to receive the input clock signal and wherein one of the at least one adjustment circuit and the at least one correction circuit is to transmit a corrected output clock signal.

Correcting duty cycle and compensating for active clock edge shift

The disclosure relates to a skew control circuit for controlling the skew between at least three clock signals, the clock signals being forwarded to different clock domains associated with the respective clock signals. The skew control circuit comprises multiple programmable delay elements arranged within a signal flow before the respective clock domain, a skew detector arrangement operable for detecting skews between at least two pairs of the clock signals, and a control circuit operable for adjusting delays caused by the programmable delay elements. The control circuit is operable for carrying out a de-skewing operation. The de-skewing operation comprises determining an order of occurrence of edges of the signals, selecting one of the programmable delay elements based on the determined order, and adjusting the delay caused by the selected programmable delay element.

Double compression avoidance

Disclosed aspects relate to a clock distribution network of a synchronous logic device. The synchronous logic device comprises multiple sub-circuits belonging to different clock domains. The clock distribution network comprises a clock source operable for providing a global clock signal, at least one programmable delay line associated with a certain sub-circuit operable for generating a local clock signal for said sub-circuit by delaying the global clock signal or a signal derived therefrom and a global skew control circuit for managing clock skew between the local clock signals. The global skew control circuit is operable for managing clock skew between at least some local clock signals by regularly adjusting the delay caused by at least one programmable delay line when in a deskewing operating mode, and disabling adjusting the delays of the programmable delay lines when in a locked operating mode.

Growing community of inventors

Ehningen, Germany

Michael V Koch