Abstract: Improved charge pump circuitry that significantly reduces voltage stress on transistor gate oxides is disclosed. The charge pump circuit according to a preferred embodiment of the present invention includes circuitry that biases the otherwise vulnerable transistors in the charge pump circuit such that the voltage across their gate oxide is reduced. The charge pump of the present invention further provides circuitry to reduce leakage current.

Abstract: A programmable logic device in which macrocell register reset time, T.sub.clear, and set time, T.sub.set, are comparable in speed to the combinatorial propagation delay time, T.sub.pd. In setting or resetting the macrocell register, the Set (Reset) signal is applied simultaneously to a clocked master latch in the macrocell register and to an output node. During the Set (Reset) period the slave latch of the macrocell register is disconnected from the output node.

Abstract: A programmable integrated circuit logic array device having one or more of the following features: (1) a bus port for receiving data directly from or making data available directly to an associated microprocessor or other similar device, (2) an internal bus (preferably with internal bus arbitration logic for resolving competing demands for utilization of the bus) for conveying data between the bus port and the logic arrays and/or between the logic arrays themselves, (3) the ability to operate either in an edge-trigger mode (in which controlled functions such as input registers are triggered by the transitional edges of control signals) or in a flow-through mode (in which controlled functions such as input registers are triggered by the states rather than the transitional edges of the control signals), and (4) the ability to operate either in a fast mode (in which timing control signals are applied substantially directly to the elements to be controlled) or in a slow mode (in which timing control signals propa

Abstract: A method and apparatus for programming programmable logic arrays using fewer chip resources is provided. The programmable elements in the programmable logic arrays are serially addressed using shift registers. The method and apparatus are particularly useful in conserving resources on a chip containing several programmable arrays.

Abstract: A delay circuit for a data manipulation circuit is provided in which data update signals to the data manipulation circuit are delayed when a data access signal is present so that data is not manipulated during accessing of the data.

Abstract: Steering logic interconnects the individual portions of a partitioned counter and are controlled by test logic to selectively apply a clock input to the first stage of each portion of the counter in sequence and to detect overflow of the individual portions so as to determine whether the various stages of each portion are properly connected together, as well as to determine whether the steering logic properly interconnects the various portions of the counter.