Abstract:
A ramp generator includes a resistance ladder (10) supplied with a constant current. Switches are closed in sequence on the resistance ladder to generate the ramp voltage. By using control logic to decode the sequence, a looped shift register is used to close the switches.
Abstract:
A stream processing system is described in which packets of an input stream each include individual timestamps which represent relative delays between the packets. A programmable counter generates continuously count values that are compared with the timestamps in the packet stream. An output controller determines whether or not to release packets from an output port based on the result of the comparison, preferably only releasing packets when the programmable count value equals the timestamp.
Abstract:
The routing of data streams is discussed, and particularly routing one or more incoming streams to one or more output destination ports. The ability to merge incoming streams is discussed so that several low bit rate input packet streams can be merged into a higher bit rate output stream. An assignment data structure identifies for each input stream the or each destination to which it is to be routed, and a packet allocation data structure holds information about the packets and information about the destination of the packets to allow a memory holding the packets to be controlled accordingly.
Abstract:
A semiconductor integrated circuit for processing a plurality of received broadcast signals, such as GPS signals, is operable in two modes: acquisition and tracking. In an acquisition mode, a separate acquisition engine is used which includes a sample reducer for combining samples of a received signal for correlation with a locally generated version of a GPS code. A serial to parallel converter converts the reduced samples to parallel words which are correlated in parallel with locally generated words of the GPS code.
Abstract:
The described embodiments of the invention relate to a voltage reference generator which can be produced using new process technologies and which is still compatible with older designs/products. This is achieved by the introduction of circuitry to generate an offset voltage independently of the main reference voltage generation circuitry.
Abstract:
A semiconductor integrated circuit for use in direct memory access (DMA) has two sources which communicate with a bus through a bus interface. A DMA access signal generator is coupled to the bus interface and asserts a DMA access output signal at a DMA access signal pin whenever either of the sources requires a DMA access. The need for separate DMA access signal pins for each of the two sources is thereby avoided. With targets on two separate integrated circuits, a single DMA access pin can be used for the two targets, while chip select signals at chip select pins on the source integrated circuit indicate which of the two targets is intended for the DMA access.
Abstract:
A method of linking a plurality of object files to generate an executable program, the method comprises identifying in the object files at least one routine to be locked into a cache when the program is executed, locating said routine at a set of memory addresses which man onto a set of cache locations and introducing into the executable program gaps at other sets of memory addresses which map onto the same set of cache locations.
Abstract:
A method of producing a semiconductor circuit is disclosed with an area saving in comparison to conventional circuit layouts. IO cells are arranged with a width multiplied by a factor, but with corresponding reduced height. ESD protection circuitry is included at a reduced rate in comparison to usual arrangements. The space saving is achieved by occupying a semiconductor area that would have been used by ESD circuitry with the IO circuitry. ESD protection is maintained but at different locations.
Abstract:
A method of locating packet identifiers held in respective memory locations in a memory, the method comprising receiving a plurality of packets, each packet including a packet identifier, searching said memory locations in a sequence to compare an incoming packet identifier with packet identifiers stored in the memory until a match is found, incrementing one of a set of counters associated respectively with the memory locations, said incremented counter being the one associated with the memory location where the match packet identifier is held, and reading values of each of the counters and using said values to determine the sequence in which the memory locations are searched for subsequent incoming packet identifiers.
Abstract:
A data transport device for transporting a data stream, the device including: a data stream processing unit for receiving an input data stream including a plurality of data items, performing processing in dependence on the content of the items and forming an output data stream including at least some of the data items; and a data item injection unit including a memory for storing a plurality of injection data items and associated with each injection data item an injection action, and an injection processor arranged to retrieve the injection action for each of the injection data items in turn and in dependence on the retrieved injection action to inject the associated injection data item into the output data stream.