Abstract: An embedded system bus is woven between a plurality of embedded master elements and at least one slave element within the FPGA device, and provides an external processor interface allowing direct access to any of the plurality of embedded slave elements. Using the embedded system bus, any of a plurality of masters may be allowed to program an embedded element, e.g., embedded FPGA logic, whereas conventional FPGAs allowed only a single master (e.g., a processor) to program the embedded FPGA logic. The embedded system bus is a group of signals, typically data, address and control, that connects system elements together and provides a basic protocol for the flow of data. The embedded system bus allows for control, configuration and status determination of the FPGA device. The embedded system bus is preferably a dedicated function available at all times for arbitrated access to allow communication between the various embedded system components.

Abstract: An embedded system bus is woven between a plurality of embedded master elements and at least one slave element within the FPGA device, and provides an external processor interface allowing direct access to any of the plurality of embedded slave elements. Using the embedded system bus, any of a plurality of masters may be allowed to program an embedded element, e.g., embedded FPGA logic, whereas conventional FPGAs allowed only a single master (e.g., a processor) to program the embedded FPGA logic. The embedded system bus is a group of signals, typically data, address and control, that connects system elements together and provides a basic protocol for the flow of data. The embedded system bus allows for control, configuration and status determination of the FPGA device. The embedded system bus is preferably a dedicated function available at all times for arbitrated access to allow communication between the various embedded system components.

Abstract: A field-programmable gate array (FPGA) having at least one programmable cell (e.g., an input/output (I/O) cell) having an output node circuit (e.g., a pad circuit) in which the output data signal and the tri-state signal are applied to a multiplexer that drives the tri-state port of an output buffer in the output node circuit. This configuration enables the output node circuit to be configured for open drain drive mode operations in a fast, predictable manner that does not need to rely on the FPGA's general routing resources.

Abstract: A high performance transport layer checksum calculation unit and method is described for use in computer data communications systems which provides simultaneous general purpose data movement and checksum calculations. Data must be copied from the main memory of a computer in order to be transmitted and often a checksum must be calculated on the data for error detection purposes. The invention involves performing both of these tasks simultaneously thus requiring only one scan of the data memory. The checksum calculation method improves throughput capacity via a unique hardware architecture supporting delayed checksumming of packet segments. A net improvement for packets larger than a certain size is achieved via partial addition during DMA controlled memory access allowing improved average cycle time per data packet segment.

Abstract: The present invention relates to time measurement apparatus and method for measuring, with picosecond precision, intervals between single edged events, where each measured interval comprises the summation of a rough clock count and fine or calibrated vernier counts of measured fractional clock periods before and after each START and STOP event selected from a calibrated vernier memory. The calibrated vernier memory takes the form of a table of linear voltage versus time developed using pseudo-random generated measurement events of random duration and random separation.