Abstract: A bus-based logic block in a self-timed integrated circuit includes N first input multiplexers, N second input multiplexers, and N lookup tables, N being greater than one. The select inputs of all N first input multiplexers are coupled together, and the select inputs of all N second input multiplexers are coupled together. A corresponding data input of each first input multiplexer is one bit of a first self-timed N-bit bus, and a corresponding data input of each second multiplexer is one bit of a second self-timed N-bit bus. Each lookup table has first and second inputs coupled to the outputs of the first and second input multiplexers. Corresponding control inputs of all N lookup tables are coupled together. Thus, all operations are performed on one or more N-bit self-timed busses, rather than on individual data signals.

Abstract: An exemplary circuit for implementing logic sharing in self-timed circuits includes a shared logic circuit, an input circuit, an output circuit, and a pipelined routing path. The shared logic circuit has first and second self-timed inputs and first and second self-timed outputs. The input circuit is coupled to output a selected one of the first or second self-timed inputs to the shared logic circuit, the selected one of the first or second inputs being determined by an arbitration circuit within the input circuit, and further to output a self-timed select signal. The output circuit is coupled to receive the first and second self-timed outputs from the shared logic circuit and to provide a selected one of the first or second outputs, the selected output being determined by the self-timed select signal. The pipelined routing path routes the self-timed enable signal from the input circuit to the output circuit.

Abstract: Circuits for merging data streams in a self-timed programmable integrated circuit. A programmable integrated circuit includes interconnected logic blocks, each including a logic circuit and an output multiplexer circuit including an arbiter and a multiplexer. Each arbiter is coupled to receive ready signals provided with first and second outputs of the logic circuit. Each multiplexer has first and second data inputs coupled to the outputs of the logic circuit, a select input programmably coupled, in one of a plurality of operating modes, to an arbiter output, and a data output coupled to an output of the logic block. The output multiplexer circuit provides an output token only when a first token indicates valid new data on the arbiter output and a second token indicates valid new data on one of the data inputs, and stores a third token received on the other data input until the other data input is selected by the multiplexer.

Abstract: Circuits for implementing gating logic in a self-timed integrated circuit. An integrated circuit includes a plurality of interconnected logic blocks, each including a logic circuit and an output circuit. Each output circuit has a data input coupled to an output of the logic circuit, a gating input, and a data output coupled to an output of the logic block. The output circuit is coupled to place a value on the data input onto the data output when the gating input has a first value and the output circuit receives tokens indicating valid new data on both the data input and the gating input of the output circuit. The output circuit is coupled to leave the data output unchanged when the gating input has a second value and the output circuit receives a token indicating valid new data on both the data and gating inputs of the output circuit.

Abstract: An exemplary circuit for implementing conditional statements in self-timed logic circuits includes first and second logic circuits, an input circuit, an output circuit, and a pipelined routing path. The first and second logic circuits each have a self-timed input and a self-timed output. The input circuit is coupled to provide a self-timed input signal to the self-timed input of a selected one of the first or second logic circuits based on the value of a control signal, and is further coupled to output a self-timed select signal. The output circuit is coupled to receive the self-timed output from the first logic circuit and the self-timed output from the second logic circuit, and to output a selected one of the self-timed outputs based on a value of the self-timed select signal. The pipelined routing path routes the self-timed select signal from the input circuit to the output circuit.

Abstract: A selection circuit, such as a multiplexer circuit, programmable to hold the output signal at a constant logic level or select 1 of n input signals as the output signal is disclosed. A first bank of transistors receives the n input signals and is controlled by a first set of memory cells. A second bank of transistors is controlled by a second set of memory cells. At least two transistors of the second bank have gates are coupled to a complemented output of one of the second set of memory cells. Each transistor in the second bank is coupled to a subset of transistors of the first bank. An output stage is coupled to the second bank of transistors. A pair of serially coupled transistors has gates coupled to two memory cells of the second set that control the at least two transistors of the second bank. The output stage outputs the constant logic level signal when the serially coupled transistors are conducting, and outputs the selected input signal when the serially coupled transistors are not conducting.