Abstract: A method and apparatus for executing a nested program loop on a vector processor, the loop comprising outer-pre, inner and outer-post portions. An input stream unit of the vector processor provides a data value to a data path and sets an associated data validity tag to ‘valid’ once per outer loop iteration, as indicated by an inner counter of the input stream unit. The tag is set to ‘invalid’ in other iterations. Functional units of the vector processor operate on data values in the data path, each functional unit producing a valid result if the data validity tags associated with inputs data values are set to ‘valid’. An output stream unit of the vector processor sinks a data value from the data path once per outer loop iteration if an associated data validity tag indicates that the data value is valid.

Abstract: A method and apparatus that allocates bandwidth among wireless sensor nodes in wireless sensor groups in a wireless sensor network (WSN) is disclosed.

Abstract: A method and apparatus for executing a nested program loop on a vector processor, the loop comprising outer-pre, inner and outer-post portions. An input stream unit of the vector processor provides a data value to a data path and sets an associated data validity tag to ‘valid’ once per outer loop iteration, as indicated by an inner counter of the input stream unit. The tag is set to ‘invalid’ in other iterations. Functional units of the vector processor operate on data values in the data path, each functional unit producing a valid result if the data validity tags associated with inputs data values are set to ‘valid’. An output stream unit of the vector processor sinks a data value from the data path once per outer loop iteration if an associated data validity tag indicates that the data value is valid.

Abstract: A method for generating a sequence of memory addresses for a multi-dimensional data structure and an address generation unit are disclosed. The address generation unit includes an ADDRESS register, a STRIDE register, and a plurality skip generators, each having SKIP, SPAN and COUNT registers. An address value is initialized to a first address and each COUNT register is initialized. For each address of the sequence an address value is output and a stride value is added to the address value. For each dimension of the data structure the COUNT register associated with the dimension is updated as each address is generated. For all dimensions, when the COUNT register value becomes zero, the skip value associated with the dimension is added to the address value and its COUNT register is reset to a specified value.

Abstract: Buffer overflow exploits in a computer are reduced by encoding linkage information associated with a subroutine, following a call to the subroutine from an application executing on the computer. The encoded linkage information is stored at a first address in a run-time stack in a memory of the computer. Upon exit from the subroutine, the value stored at the first address in the run-time stack is retrieved and decoded to obtain decoded linkage information. Execution of the application continues in accordance with the decoded linkage information. Subroutine data written to the stack is not encoded.

Abstract: A method and apparatus that allocates bandwidth among wireless sensor nodes in wireless sensor groups in a wireless sensor network (WSN) is disclosed.

Abstract: A method and apparatus for the elimination of prolog and epilog instructions in a vector processor. To eliminate the prolog, a functional unit of the vector processor has at least one input for receiving an input data value tagged with a data validity tag and an output for outputting an intermediate result tagged with a data validity tag. The data validity tags indicate the validity of the data. Before a loop is executed, the data validity tags are set to indicate that the associated data values are invalid. During execution of the loop body a functional unit checks the validity of input data. If all of the input data values are valid the functional operation is performed, the corresponding data validity tag set to indicate that the result is valid. If any of the input data values is invalid, the data validity tag of the result is set to indicate that the result is invalid. To eliminate the epilog, an iteration counter is associated with each sink unit of the vector processor.

Abstract: A method and apparatus for power reduction in a processor controlled by multiple-instruction control words. A multiple-instruction control word comprises a number of ordered fields, with each ordered field containing an instruction for an element of the processor. The sequence of instructions for a loop is compressed by identifying a set of aligned fields that contain NOP instructions in all of the control words of the sequence. The sequence of control words is then modified by removing the fields of the identified aligned set containing NOP instructions and adding an identifier that identifies the set of fields removed. The sequence of control words is processed by fetching the identifier at the start the loop, then, for each control word in the sequence, fetching a control word and reconstructing the corresponding uncompressed control word by inserting NOP instructions into the compressed control word as indicated by the identifier.

Abstract: A communication signal for transmitting a sequence of tokens over an interconnection having three wires in which each of the three wire transmits a signal corresponding to one bit of a 3-bit symbol. The tokens are determined by the transitions between the symbols. In one embodiment, RF emission is minimized and self-clocking is achieved by changing exactly one bit of a symbol at each transition. A receiver detects a transition in the signal on one of the three wires, identifies the transition from the previous and current 3-bit symbols and determines the information token associated with the transition.

Abstract: A cache for storing data elements is disclosed. The cache includes a cache memory having one or more lines and one or more cache line counters, each associated with a line of the cache memory. In operation, a cache line counter of the one or more of cache line counters is incremented when a request is received to prefetch a data element into the cache memory and is decremented when the data element is consumed. Optionally, one or more reference queues may be used to store the locations of data elements in the cache memory. In one embodiment, data cannot be evicted from cache lines unless the associated cache line counters indicate that the prefetched data has been consumed.

Abstract: A bus filter includes a first bus interface connected to a system bus for receiving a virtual memory address and a second interface connected to the system bus for transmitting a physical memory address. In operation, an address translation unit, such as a translation lookaside buffer, determines the physical memory address from the virtual memory address. The bus filter may be used to couple a processing device, such as an accelerator, to a system having a core processor and an external memory unit coupled by a bus.

Abstract: A system and method for calculating memory addresses in a partitioned memory in a processing system having a processing unit, input and output units, a program sequencer and an external interface. An address calculator includes a set of storage elements, such as registers, and an arithmetic unit for calculating a memory address of a vector element dependent upon values stored in the storage elements and the address of a previous vector element. The storage elements hold STRIDE, SKIP and SPAN values and optionally a TYPE value, relating to the spacing between elements in the same partition, the spacing between elements in the consecutive partitions, the number of elements in a partition and the size of a vector element, respectively.

Abstract: A method and apparatus for the elimination of prolog and epilog instructions in a vector processor. To eliminate the prolog, a functional unit of the vector processor has at least one input for receiving an input data value tagged with a data validity tag and an output for outputting an intermediate result tagged with a data validity tag. The data validity tags indicate the validity of the data. Before a loop is executed, the data validity tags are set to indicate that the associated data values are invalid. During execution of the loop body a functional unit checks the validity of input data. If all of the input data values are valid the functional operation is performed, the corresponding data validity tag set to indicate that the result is valid. If any of the input data values is invalid, the data validity tag of the result is set to indicate that the result is invalid. To eliminate the epilog, an iteration counter is associated with each sink unit of the vector processor.

Abstract: A system and method for calculating memory addresses in a partitioned memory in a processing system having a processing unit, input and output units, a program sequencer and an external interface. An address calculator includes a set of storage elements, such as registers, and an arithmetic unit for calculating a memory address of a vector element dependent upon values stored in the storage elements and the address of a previous vector element. The storage elements hold STRIDE, SKIP and SPAN values and optionally a TYPE value, relating to the spacing between elements in the same partition, the spacing between elements in the consecutive partitions, the number of elements in a partition and the size of a vector element, respectively.