Arm Limited

Simon Crossley

Alistair Crone Bruce

Andrew David Tune

Anitha Kona

Antony John Harris

Steven Douglas Krueger

Richard Andrew Paterson

Robin Hotchkiss

Ramnath Bommu Subbiah Swamy

A method for correlating first and second local time counts in first and second integrated circuits is provided. The first and second integrated circuits communicate via a communication network. A separate time control signal path is also provided between the integrated circuits. The method comprises determining a signal propagation latency associated with propagation of a latency determining signal between the integrated circuits on the time control signal path, and correlating the first and second local time counts in dependence on the signal propagation latency and a time correlating signal transmitted on the time control signal path.

Correlating local time counts of first and second integrated circuits

An apparatus and method are provided for performing verification tests for a design of a data processing system. The apparatus comprises a system under verification representing at least part of the design of the data processing system, and a transactor for connecting to an interface of the system under verification, and for generating signals for input to the system under verification via the interface during performance of the verification tests. Profile storage stores a profile providing a statistical representation of desired traffic flow at the interface, the statistical representation providing statistical information for a plurality of traffic attributes and also identifying at least one dependency between such traffic attributes. The transactor then references the profile in order to determine the signals to be generated, such that the signals generated take account of the specified dependencies identified in the profile. Such a mechanism enables the transactor to more realistically replicate the traffic flow that will be observed in the real system. Another aspect to the present invention provides a mechanism for generating such profiles.

Use of statistical representations of traffic flow in a data processing system

An integrated circuit includes a signal source and a signal destination linked by a signal path. Error correction codes (e.g. Hamming codes) are applied to the signals to be transmitted. Errors detected in the signal transmission are used to control an operating parameter of the signal path, such as signal voltage level, body bias voltage, clock frequency and/or temperature. The control applied is closed-loop feedback control seeking to maintain a finite non-zero predetermined error rate. The technique can also be used between a memory accessing integrated circuit and a separate memory integrated circuit. Furthermore, the technique can be used to provide fixed, but differing operating parameters for signal lines within a signal path. Control signals which may be timing critical are passed with appropriate operating parameters, such as a high signal voltage level, where as other signals, such as address and data signals, are passed with a different appropriate operating parameter, such as a low signal voltage level.

Operating parameter control for integrated circuit signal paths

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Sheffield, United Kingdom

Simon Crossley