Abstract: The present invention relates to a contacting structure on a lightly-doped P-type region of a semiconductor component, this P-type region being positively biased during the on-state operation of said component, including, on the P region a layer of a platinum silicide, or of a metal silicide having with the P-type silicon a barrier height lower than or equal to that of the platinum silicide.

Abstract: A method of operating a cache memory is described in a system in which a processor is capable of executing a plurality of processes, each process including a sequence of instructions. In the method a cache memory is divided into cache partitions, each cache partition having a plurality of addressable storage locations for holding items in the cache memory. A partition indicator is allocated to each process identifying which, if any, of said cache partitions is to be used for holding items for use in the execution of that process. When the processor requests an item from main memory during execution of said current process and that item is not held in the cache memory, the item is fetched from main memory and loaded into one of the plurality of addressable storage locations in the identified cache partition.

Abstract: A circuit is described which allows a scan latch to selectively pass inputs derived from either of two test outputs, e.g. scan test and built-in self-test data, but which does not apply an added delay to a data path when this is instead selected.

Abstract: Data stream transfer apparatus for receiving a data stream of data cells at variable time intervals and transmitting data frames at predetermined time intervals, including a receiving apparatus, a buffer memory, a data transfer interface, a central processing unit (CPU), and a memory access unit. The receiving apparatus receives the data cells and stores them in the buffer memory. The data transfer interface transfers data frames out of the apparatus at the predetermined time intervals and generates an indication that the data frame has been transferred. The memory access unit receives data defining a location of a data frame in the buffer memory, accesses the buffer memory to retrieve that data frame and transmits that data frame to the data transfer interface. The CPU, upon receiving the indication, determines a time for transfer of a subsequent data frame, and upon reaching that time, transmits to the memory access unit the location of the subsequent frame in the buffer memory.

Abstract: An arbiter for arbitrating between a plurality of requests from a plurality of requesters, said arbiter being arranged to assign an order of priority of said requesters, the requester having the highest priority and which has made a request winning the arbitration, wherein the arbiter determines a new priority for said winning requester, said winner being given a priority different from the lowest priority.

Abstract: A method of automated generation of a set of design data defining a system model from an architecture database which is configured to hold in an electronic storage medium architectural parameters wherein each architectural parameter is defined by a primary key field and a set of fields holding subsidiary data relating to the primary key, the method comprising, reading the primary key for each architectural parameter, generating in an electronic storage medium a structured definition entry of the architectural parameter in an electronically readable format, the structured definition entry being associated with an identification field defining the parameter, and loading the primary key into the identification field and the subsidiary data into the structured definition file, and wherein the structured definition entry takes the form of a programming definition of the architectural parameter in a modelling language.

Abstract: A memory system comprises a memory array having a plurality of memory locations; a plurality of write ports for writing to the memory array; write protection circuitry for preventing more than one memory location from being addressed at the same time in a write operation, the write protection circuitry providing one write enable signal for each write port, the write enable signals being applied to the memory array; and circuitry for controlling the timing of the application of the write enable signals to the memory array, the circuitry for controlling the timing being upstream of the write protection circuitry.

Abstract: An apparatus and method for determining a minimum clock delay provided to sense amplifiers of a memory array. The method first determines a response time of the overall memory circuit by varying the delay of an external clock until the output of the memory circuit is just valid. Then an externally provided sense amplifier clock is substituted for the internal sense amplifier clock and the instant of application of the externally provided sense amplifier clock is varied until the circuit output is just valid.

Abstract: A cache system is provided which includes a cache memory and a cache refill mechanism which allocates one or more of a set of cache partitions in the cache memory to an item in dependence on the address of the item in main memory. This is achieved in one of the described embodiments by including with the address of an item a set of partition selector bits which allow a partition mask to be generated to identify into which cache partition the item may be loaded.

Abstract: A method and apparatus for determining the write-recovery of an embedded memory by performing successive pseudo-write operations followed by read operations until a “just-valid” result is achieved. The read operations may include addressing memory cells storing a logic value opposite that of memory cells coupled to the bit lines in the pseudo-write operations.

Abstract: The present invention relates to a memory having sense amplifiers and data latches, the data latches being used in a test mode to form a signature register. In a normal operation mode, the data latches are form write data latches.

Abstract: A MOS technology power device includes a semiconductor material layer of a first conductivity type, a conductive insulated gate layer covering the semiconductor material layer, and a plurality of elementary functional units. The conductive insulated gate layer includes a first insulating material layer placed above the semiconductor material layer, a conductive material layer placed above the first insulating material layer, and a second insulating material layer placed above the conductive material layer. Each elementary functional unit includes an elongated body region of a second conductivity type formed in the semiconductor material layer. Each elementary functional unit further includes an elongated window in the insulated gate layer extending above the elongated body region. Each elongated body region includes a source region doped with dopants of the first conductivity type, intercalated with a portion of the elongated body region wherein no dopant of the first conductivity type are provided.

Abstract: A computer system has compact instructions avoiding the need for redundant bit locations and needing simple decoding. Logic circuitry is arranged to respond to an instruction set comprising a plurality of selectable instructions of different bit lengths. Each instruction is based on a format of predetermined bit length and a predetermined sequence of instruction fields each of a respective predetermined bit length. Some instructions omit a selected one of the fields and include an identifier of less bit length than the omitted field to indicate which field is omitted. Thus this bit length of the instruction is compressed. The logic circuitry is operable to restore the omitted field on execution of the instruction.

Abstract: A method is described for verifying the output from an analogue simulation model of a hardware circuit. The method includes the steps of stimulating the analog model by applying a preselected voltage to an input pin of the analog model, driving one or more selected output pins of the analog model with a test voltage having a selected drive strength different from an expected output drive strength, measuring the output voltage of each output pin, comparing the measured output voltage and the expected output voltage and responsive to said comparison, providing a verifying output if the measured and expected voltages are not in contradiction.

Abstract: A memory for a computer system that includes a plurality of memory banks which provide an interleaved memory region as well as X and Y memory regions. Each memory access address includes a most significant set of bits indicating which of the interleaved, X, or Y memory regions is to be accessed. Each memory access address also includes a least significant set of bits indicating an address within the bank of the access region. At least one bit in the least significant set is a bank selector and one bit of the most significant set of bits is an X or Y region selector.

Abstract: A comparator circuit with comparing means for comparing first and second voltages, has current source circuitry for providing current to said comparing means, said current source circuitry having an input for receiving a clock signal having first and second states, whereby the comparing means starts to compare the first and second voltages when the clock signal makes a transition from the first state to the second state; and means for determining when said comparing means has completed a comparison of said first and second voltages and for switching off said current source circuitry and hence said comparing means when said comparison has been completed.

Abstract: A computer system has a processor, a cache and a main memory. A cache coherency mechanism ensures that the contents of the cache are coherent with respect to main memory by the provision of cache coherency instructions which each specify: 1) an operation to be executed on the contents of a location in the cache; and 2) an address in main memory. The operation is executed for the contents of the location in the cache which could be filled by an access to that address in main memory if the executing process normally has access to that address in main memory, regardless of whether or not the contents of the specified address in main memory are held at that location in the cache. This provides an extra degree of freedom because it is not necessary for the cache coherency operation to be requested in respect of a particular address stored in the cache. The instruction can specify any address which would map onto that cache location.

Abstract: A sense amplifier circuit has two inputs for connection to complementary bit lines and an output terminal. The circuit comprises control circuitry responsive to control input for selectively tristating the output terminal.

Abstract: An integrated circuit including serial data input and output pins, on-chip functional circuitry and test logic, a test access port controller, and a data adaptor. The test access port controller is connected to effect communication of serial data across tile chip boundary via the input and output pins and is connectable to the test logic to effect communication of serial test data off-chip. The data adaptor is connectable to the input and output pins via the test access port controller. The data adaptor includes an interface for communicating data in the form of serial bits with the test access port controller under control of a first clock signal, and an interface for communicating data in the form of successive sets of parallel data and control signals with the on-chip functional circuitry under control of a second clock signal that is generated independently of the first clock signal.

Abstract: An adapter device for assisting debugging of a microprocessor on a single integrated circuit chip, the integrated circuit chip comprising an on-chip CPU with a plurality of registers, a communication bus providing a parallel communication path between the CPU and a first memory local to the CPU and an external communication port connected to the said bus on the integrated circuit chip, the communication port having an internal connection to the said bus of an internal parallel signal format and an external connection to the adapter unit of a first external format less parallel than the said internal format; the adapter device comprising a first communication unit for connection to the communication port with the first external format; a second communication unit for connection to an external computer device with a second external format having a higher latency than the first external format; a second memory local to the adapter device; and a processing unit local to the adapter device and operable: (a) in a f