| Patent application number | Description | Published |
|---|
| 20080235707 | Data processing apparatus and method for performing multi-cycle arbitration - A data processing apparatus and method are provided for arbitrating between multiple access requests seeking to access a plurality of resources sharing a common access path. At least one logic element issues access requests requesting access to the resources, and each access request identifies which of the resources is to be accessed. Arbitration circuitry performs a multi-cycle arbitration operation to arbitrate between multiple access requests to be passed over the common access path, the arbitration circuitry having a plurality of pipeline stages to allow a corresponding plurality of multi-cycle arbitration operations to be in progress at any one time. Filter circuitry is provided which has a plurality of filter states, the number of filter states being dependent on the number of pipeline stages of the arbitration circuitry, and each resource being associated with one of the filter states. For a new multi-cycle arbitration operation to be performed by the arbitration circuitry, the filter circuitry selects one of the filter states that has not been selected for any other multi-cycle arbitration operation already in progress within the pipeline states of the arbitration circuitry. Then, it determines as candidate access requests for the new multi-cycle arbitration operation those access requests that are seeking to access a resource associated with the selected filter state. Such an approach allows efficient multi-cycle arbitration to take place even where the resources may have inter-access timing parameters associated therewith which prevent them from being able to receive access requests every clock cycle. | 09-25-2008 |
| 20080320292 | Self programming slave device controller - A self programming slave device controller is described which comprises interface circuitry and control circuitry. The interface circuitry is responsive to one or more configuration parameters to communicate data between the slave device controller and a slave device in accordance with the one or more configuration parameters. The control circuitry is responsive to one or more operating parameter signals indicative of one or more operating parameters influencing current performance characteristics of the slave device to set the one or more configuration parameters so as to control an access operation for accessing the slave device to accommodate the current performance characteristics of the slave device. In this way, an access operation can be conducted efficiently and reliably having regard to the current performance characteristics of the slave device. This makes it possible to automatically adjust configuration parameters used to control an access operation in dependence on changes to operating parameters of the slave device which may influence the performance characteristics. | 12-25-2008 |
| 20100088443 | Data processing apparatus and method for arbitrating access to a shared resource - A data processing apparatus and method are provided for arbitrating access to a shared resource. The data processing apparatus includes a plurality of requester elements sharing access to the shared resource, and arbitration circuitry which is responsive to requests asserted by one or more of the requester elements for access to the shared resource, to perform a priority determination operation to select one of the asserted requests as a winning request. Each of the asserted requests has a priority level associated therewith, and the apparatus further comprises relative priority ordering circuitry for attributing relative priorities to the plurality of requester elements. The arbitration circuitry is responsive to the asserted requests to perform the priority determination operation in order to select as the winning request the request asserted by the requester element with the highest relative priority whose asserted request has a priority level not exceeded by any other asserted request. This provides a very flexible mechanism for performing arbitration, whilst allowing priority levels to be set on a request-by-request basis, thereby facilitating use of the arbitration circuitry with various quality of service mechanisms. | 04-08-2010 |
