International Business Machines Corporation

Other

Jonathan Henry Raymond

Eric Todd Hennenhoefer

Sebastian Theodore Ventrone

Hayden C Cranford, Jr

Stephen Dale Wyatt

Dac C Pham

Randall S Smith

A network driver includes first and second driver circuits and a controller which controls the driver circuits. The first driver circuit is coupled to a first node, and the first driver circuit sources first and second discrete currents to the first node and sinks first and second discrete currents from the node. The second driver circuit is coupled to a second node, and the second driver circuit sources the first and second discrete currents to the second node and sinks the first and second discrete currents from the second node. The controller controls the driver circuits so that the first driver circuit sources and the second driver circuit sinks the first current followed by the second current and so that the first driver circuit sinks and the second driver circuit sources the first current followed by the second current. Related methods are also discussed.

Data network drivers including balanced current supplies and related

Apparatus and method for emulating a circuit having at least one multiport RAM that requires at least two programmable device to be emulated. The multiport RAM has an array of storage elements, a read multiplexer, and a write multiplexer and is partitioned into a number of slices, each of which is capable of being programmed into one of an array of programmable devices. In one embodiment, each slice is another multiport RAM having the same depth, number of read ports, and number of write ports as the multiport RAM being emulated, but having a narrower width than the multiport RAM being emulated. In another embodiment, the multiport RAM is partitioned into read slices and write slices, which will typically be of different widths. The read slices comprise the read multiplexers. The write slices comprise the array of storage elements and the write multiplexers.

Apparatus and method for partitioning multiport rams

An optimized multiplexer structure reduces the cost in emulation gates in an emulator test system. Extra encoding and decoding logic is added to form a selector with multiple separate subblocks so that the data flow subblock has a reduced input/output (I/O) control path. The circuit reduces the number of control bits from N bits to log.sub.2 N bits.

Optimized multiplexer structure for emulation systems

A control circuit and protocol are disclosed for an integrated circuit (such as a static PLA) wherein standby power is minimized during an idle processor state condition without loss of circuit outputs. For static PLAs, control circuits shutoff any active current path and drive the logic array outputs to zero whenever an idle state condition exists. Inputs to the logic array are held in static latches associated with the static PLA. The novel halt protocol includes: powering-down the logic macro upon initiation of an idle state by halting all internal clocks and then decoupling the logic array from power supply voltage VDD. Circuit power-up includes reactivating the logic array by first coupling the array to supply voltage VDD and allowing sufficient time for the outputs of the array and any associated logic to stabilize; and then restarting the previously halted internal clocks. Analogous techniques are also described for dynamic PLAs.

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Underhill, VT, United States of America

Jonathan Henry Raymond