Icera, Inc.

Peter Cumming

Stephen Felix

Andrew Glyn Bond

Colman Hegarty

Jon Mangnall

Hlond Marcin

Coleman Hegarty

A method of controlling the clock frequency of a processor executing software in a plurality of active periods, the method comprising, for each period: supplying to a power management application at least one parameter defining an execution profile for the period having high frequency and low frequency operating intervals; the power management application determining, based on said profile, granted clock frequencies for the high and low frequency operating intervals; the processor supplying to the power management application at the commencement of a period an operating cycle requirement for the period; the power management application determining, for each period, based on the operating cycle requirement, the length of the low frequency interval; and controlling the clock frequency in each interval based on the granted clock frequencies determined by the power management application.

Method and system for controlling clock frequency for active power management

An integrated circuit is disclosed herein. In one embodiment, the integrated circuit includes: a processor; a plurality of external pins operatively coupled to the processor; and a permanently written memory operatively coupled to the processor, the memory having a plurality of regions each storing one or more respective boot properties for booting the processor. The processor is programmed to select one of the regions in dependence on an indication received via one or more of the external pins, to retrieve the one or more respective boot properties from the selected region, and to boot using the one or more retrieved boot properties.

Booting an integrated circuit

A circuit comprising: an execution unit; a plurality of addressable devices; and a data transfer engine coupled to the execution unit and to the devices, operable to fetch a plurality of descriptors under control of the execution unit, and based on each of the fetched descriptors to perform a transfer of data from a respective first to a respective second of the devices. The DMA engine comprises delay circuitry operable to block, during a delay period running from an earlier of the transfers, any later of the transfers involving at least one of the same devices as the earlier transfer, the delay circuitry being arranged to control the blocking in dependence on an indication received in one of the descriptors.

Data transfer engine with delay circuitry for blocking transfers

A circuit and method for determining the frequency of a first oscillating reference signal generated by a first reference oscillator. The circuit comprises: a second reference oscillator arranged to generate a second oscillating reference signal having a known frequency, a boot memory storing boot code comprising clock configuration code, and a processor coupled to the boot memory and the second reference oscillator. The processor is arranged to execute the boot code from the boot memory upon booting, wherein when executed the clock configuration code operates the processor to determine the frequency of the first reference signal by reference to the second reference signal.

Clock configuration

An integrated circuit comprising: a processor; a plurality of external pins operatively coupled to the processor; and a permanently written memory operatively coupled to the processor, the memory having a plurality of regions each storing one or more respective boot properties for booting the processor. The processor is programmed to select one of the regions in dependence on an indication received via one or more of the external pins, to retrieve the one or more respective boot properties from the selected region, and to boot using the one or more retrieved boot properties.

A circuit and corresponding method for transferring data. The circuit comprises: a CPU; a plurality of addressable devices; and a DMA engine coupled to the CPU and to those devices, the DMA engine comprising a plurality of DMA contexts each having fetch circuitry for fetching a DMA descriptor indicated by the CPU and transfer circuitry for transferring data from one to another of the devices based on a fetched descriptor. The DMA engine further comprises switching means operable to control a group of the contexts to alternate in a complementary sequence between fetching and performing a transfer, such that alternately one or more contexts in the group fetch while one or more others perform a transfer.

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Wickwar, United Kingdom

Peter Cumming