Abstract: A group of function cells (e.g., 40), each created from one or more implementations of a fixed basic cell (20), are utilized in designing a layout for at least part of an integrated circuit. Each basic cell implementation contains a plurality of unconnected transistors (Q1-Q10) arranged in a transistor pattern identical to, or a mirror image of, the transistor pattern in each other basic cell implementation. Transistors of a specified polarity type in each basic cell implementation are normally of two or more different current-carrying capabilities. Each function cell has an interconnection network (42-44) for electrically interconnecting transistors in that function cell to perform a specified electronic function. The function cells typically form a cell library from which certain function cells are selected for generating the layout. The present layout technique is particularly applicable to laying out datapath circuitry (90) in an integrated circuit.

Abstract: An apparatus for multiplexing a pair of test clock signals and a pair of system clock signals onto a pair of output clock signals includes a first means for coupling a first test clock signal to a first output clock signal when a test mode control signal is active, for driving the first output clock signal to an inactive clock signal level when the test mode control signal transitions to an inactive state, and for coupling a first system clock signal to the first output clock signal beginning with a first full clock pulse of the first system clock signal which occurs after the test mode control signal transitions to the inactive state.

Abstract: A system and method for generating and optimizing clock signals with non-overlapping edges on a chip using a unique programmable on-chip clock generator. Overlapping of the edges of the clocking signals is avoided by adjusting an amount of delay introduced in the on-chip clock generator circuit. The amount of delay is adjusted by programming the on-chip clock generator using either hardware and/or software programming. In hardware programming, the amount of delay adjusted by physically altering the composition of delay elements in the on-chip clock generator. In software programming, the delay is adjusted using software commands to control the operation of delay elements in the on-chip clock generator, or to select the paths that delay the signals.

Abstract: A system and method for reducing the amount of ground bounce in output buffer circuits. The invention includes a first control circuit to control the amount of time it takes for a pull-up FET to be turned on, and thus the amount of time it takes for an output signal of the output buffer circuit to transition from a low to a high state. The invention also includes a second control circuit to control the amount of time it takes to turn on a pull down FET and thus the amount of time it takes for the output signal of the output buffer circuit to transition from a high to a low state. First and second control circuits each include an additional FET for controlling the amount of current supplied to the pull-up and pull-down FET, respectively. Each additional FET is driven by a voltage reference signal which is above the threshold of the additional FET.