Abstract: An interface circuit for use in the layout of padframe interface circuits for field programmable gate arrays having a plurality of I/O cells each of which may be programmed as an input or an output (or both) and a programmable connection matrix which provide programmable pathways between the data output signals generated by the core array of logic blocks and I/O cells programmed as outputs and provide programmable pathways between I/O cells programmed as inputs and data input conductors going into the core array. The interface circuits are all substantially identical in structure, and each includes a sufficient number of power and ground connections to supply adequate current to the number of I/O cells the interface has. Each interface circuit also includes at least one and preferably two open spaces into which conductive paths may be laid out to carry power to the core array or carry dedicated signals to circuits other than the core which also reside on the integrated circuit.

Abstract: A high speed active link switching technology suitable for implementing field programmable gate arrays using current mode logic in the high speed data path, and CMOS steering logic outside the high speed data path to enable the high speed switching logic and to implement multiplexer, selector and crossbar switch functions. High speed emitter follower logic compatible with the high speed switching logic for level shifting, buffering, and providing more current sink or source capacity is also disclosed. An advantage of the active link technology disclosed herein is that the active links do not degrade rise and fall times of high speed data signals nearly as much as the passive links of prior art field programmable gate arrays thereby enabling use of FPGAs in higher speed applications than was previously possible.

Abstract: A programmable logic device includes a plurality of logic cells in which logic functions are performed, a plurality of input lines for supplying signals to be processed by the logic cells, a plurality of output lines for receiving signals that have been processed by the logic cells, and a plurality of repeater circuits combining bipolar and CMOS transistor technologies for transferring data from one point in the PLD to another point. Unidirectional repeater circuits transfer data from a first data bus in the PLD to a second data bus in the PLD. Bidirectional repeater circuits maintain signal integrity by transferring data along the length of a single PLD data bus. The bipolar technology in the repeater circuits provides superior speed in data transfer, while the CMOS technology limits power consumption of the repeater circuits.