摘要:
A programmable logic array (PLA) in accordance with the invention achieves a maximum amount of depopulation of programmable connections while sill implementing a logic function and maintaining flexibility for future reprogramming. In addition, a PLA in accordance with the invention can be built so that no matter what functionality is programmed, performance characteristics for the device are maintained. Further, a PLA in accordance with the invention does not require a regular array structure.
摘要:
A PLD comprises a programmable first AND array whose inputs are selectively connectable to input lines and whose outputs are selectively connectable to a programmable second OR array. The PLD further comprises a programmable third AND array whose inputs are selectively connectable to the input lines, and whose outputs are fixedly connected to inputs of a fixed fourth OR array. The outputs from the second OR array are also connected in a fixed manner to the fourth OR array. This arrangement overcomes some of the weaknesses in both the conventional PAL and PLA architectures while retaining most of their strengths.
摘要:
A programmable logic device that provides an AND gate array connected to an OR gate array connected to a third logic level, a logic expander module (121, 123). The module provides programmable selection of any of 16 one- and two-variable logic functions or any of 256 one-, two- and three-variable logic functions. In one embodiment (11, 61), the invention uses logic function gates such as AND, OR, XOR and inverter gates to form the logic functions. In a second embodiment (91) and a third embodiment, a look-up table and an array of pass transistors, respectively, are used to form the logic functions.
摘要:
A multiple-input Josephson AND gate having a plurality of input ports (A₁ - A₄) comprises a plurality of Josephson logic gate elements (11 - 14) provided in number corresponding to a number of said input ports and cascaded with each other from a first stage to a final stage, each of the Josephson logic gate elements of said first through final stages including: a superconducting quantum interferometer (S₁ - S₄) for producing an output signal in response to a transition from a superconducting state to a finite voltage state, an input line connected to a corresponding input port for carrying thereon an input current, the input line being coupled magnetically to the superconducting quantum interferometer for transferring the input current to said superconducting quantum interferometer; and a biasing part (J₂ - J₄) for supplying a bias current to the superconducting quantum interferometer with a level such that the superconducting quantum interferometer causes the transition to the finite voltage stage in response to the input current supplied to the input line, wherein each of the biasing part of the second through final stages are supplied with the output signal of the superconducting quantum interferometer of the previous stage as a trigger signal and produces the bias current in response to the trigger signal.
摘要:
A novel ECL Programmable Logic Array (PLA) is provided which operates as an ECL PLA, having ECL voltage level compatible input and output leads, thereby providing a high-speed PLA. A unique programming means is provided which allows the ECL PLA to be programmed using TTL-compatible programming voltage levels, such as are provided by common and inexpensive prior art TTL PLA programmers. In another embodiment higher speed is achieved by the design of each sense amplifier using emitter function logic such that the sense transistor and load functions a cascode amplifier. In another embodiment a lower power PLA device is achieved by utilizing a switched current source pull down means for pulling down the rows of the PLA array. In another embodiment low power and user convenience is achieved by allowing each pair of output terminals to share a predefined set of product terms. In another embodiment of this invention, each output terminal is capable of having its output polarity programmed, in order to provide either a desired product term, or the inverse of that product term.
摘要:
Disclosed is a programmable logic array (PLA), comprising an AND plane comprising a plurality of input lines (10) and a plurality of product term lines (11) crossing the input lines (10), an OR plane comprising the product term lines (11) and a plurality of output lines (12) crossing the product term lines (11), a power source VDD providing an electrical power to the AND and OR planes, and control line for controlling the supply of the electric power to the AND and OR planes, wherein the electrical power from the power source VDD is provided to the PLA when a signal indicating the use of the PLA is provided to the control line, and the supply of the electrical power from the power source VDD to the PLA is stopped on receipt of a signal designating that the PLA is in the unused state. In addition, various data processing systems incorporating the PLA are disclosed.