Ericsson Gmbh

Telefonaktiebolaget Lm Ericsson (publ)

David Barrow

Clarence V Roberts

Rajaram Ramesh

Essam Abdelfattah Sourour

Greg Bottomley

Paul Wilkinson Dent

Patricia Roberts

An integrated circuit includes a DMA controller for performing conventional DMA transfers and for backing-up and restoring data during low power events. The integrated circuit includes one or more processor components, one or more peripheral components, a power management circuit and the DMA controller. The power management circuit manages power control within the integrated circuit. The DMA controller includes a DMA engine for executing DMA transfers between different ones of the components and memory based on configuration parameters provided to the DMA engine. A detection circuit configured determines if the power management circuit initiates a power state change. The DMA controller also has circuitry for providing a first set of configuration parameters to the DMA engine if no change in power state is detected and overriding the first set of configuration parameters with a second set of configuration parameters if a change in power state is detected.

DMA assisted data backup and restore

A DMA controller maintains a count of data transferred in each DMA operation, and saves the transferred data count at the end of the DMA operation. The DMA controller may then begin a subsequent DMA transfer operation, without waiting for a processor to read the transferred data count. The transferred data count may be written to memory at an address specified in a transferred data count save address register; may be saved to a transferred data count register dedicated to the DMA channel; or may be saved to a transferred data count register shared between two or more DMA channels. The processor may read the transferred data count and, if applicable, clear the relevant transfer data count register, subsequent to the DMA controller beginning another DMA operation on that DMA channel.

DMAC to handle transfers of unknown lengths

A flexible sliding correlator for use in a spread spectrum receiver divides baseband signal samples into different groups, associates each group with a different section of a spreading code, and combines ones of the signal samples with corresponding values in the spreading code section. The groupings and spreading code sections can be changed during operation of the receiver to maximize performance of the receiver under different or changing conditions. In addition, the sample and spreading code value combinations can be further combined in different ways, and the further combinations can be changed during operation of the receiver. According to another aspect of the invention, the baseband signal can be sampled either uniformly or non-uniformly. The phase and frequency of the baseband sampling can be adjusted during operation of the receiver so that samples are taken very close to the optimum sampling position, at the peak of a chip waveform in the baseband signal.

Flexible sliding correlator for direct sequence spread spectrum systems

A spread spectrum modulated signal generator is disclosed that reduces the storage requirement for storing values representing filter responses of input signal samples in a digital filter by taking advantage of time-reversal symmetry of the responses. Moreover, the disclosed signal generator supports up-ramping and down-ramping for smooth transmission of spread spectrum modulated signals.

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Durham, NC, United States of America

David Barrow