Lattice Semiconductor Corporation

Quicklogic Corporation

Senani Gunaratna

Brad Sharpe-Geisler

Ting Yew

Ket-Chong Yap

Wilma Waiman Shiao

Andrew K Chan

Ronald L Cline

James M Apland

Timothy Saxe

Stephen U Yao

SunilKumar G Mudunuri

Various techniques are provided to efficiently implement user designs in programmable logic devices (PLDs). In one example, a programmable logic device (PLD) includes a plurality of programmable logic blocks (PLBs) and at least first and second logic cells within at least one of the PLBs, where each logic cell includes a lookup table (LUT) and associated mode logic configured to receive a LUT output signal from the LUT. The associated mode logic is configured to use a single physical signal output to provide a logic cell output signal corresponding to a selected logic function operational mode, ripple arithmetic operational mode, or extended logic function operational mode for each logic cell.

Multiple mode device implementation for programmable logic devices

Various techniques are provided to efficiently implement user designs in programmable logic devices (PLDs). In one example, a programmable logic device (PLD) includes a plurality of programmable logic blocks (PLBs) and a plurality of logic cells within at least one of the PLBs, where each logic cell includes a four input lookup table (4-LUT) configured to provide a 4-LUT output signal to associated carry logic. Each logic cell is configurable according to at least two selectable operational modes including a logic function output mode and a ripple arithmetic output mode, and at least three of the 4-LUT inputs are interchangeable when a selected operational mode comprises the ripple arithmetic output mode.

Flexible ripple mode device implementation for programmable logic devices

Various techniques are provided to efficiently implement selective power gating of routing resource configuration memory bits for programmable logic devices (PLDs). In one example, a PLD includes a routing circuit configured to selectively route input nodes to an output node. The PLD further includes configuration memory cells configured to store configuration bit values to control the routing circuit. The PLD further includes a power circuit configured to power the configuration memory cells while storing the configuration bit values. The PLD further includes an enable bit memory cell configured to store an enable bit value to interrupt at least one connection of the power circuit to the configuration memory cells. The configuration memory cells are configured to provide, in response to an interruption of the connection, default configuration bit values to the routing circuit to prevent routing the input nodes to the output node. Additional systems and related methods are provided.

Selective power gating of routing resource configuration memory bits for programmable logic devices

A programmable logic is provided that uses only NMOS pass transistors to pass a true output signal to an internal true node and to pass a complement output signal to an internal complement node. The internal true and complement nodes are cross-coupled through PMOS transistors so that the discharge of one of the internal true and complement nodes switches on a corresponding one of the cross-coupled PMOS transistors to charge a remaining one of the internal true and complement nodes.

High speed complementary NMOS LUT logic

A control circuit is provided that enables a register to provide a synchronous initialization capability as well as an asynchronous capability despite the register having no asynchronous input.

Shared logic for multiple registers with asynchronous initialization

An integrated circuit includes a programmable logic device, a dedicated device, and an interface circuit between the two. The interface circuit can be easily modified to accommodate the different interface I/O demands of various dedicated devices that may be embedded into the integrated circuit. In one embodiment, the interface circuit may be implemented using a plurality of mask programmable uni-directional interface buffer circuits. The direction of any desired number of the interface buffer circuits can be reversed based on the needs of a desired dedicated device by re-routing the conductors in the interface buffer circuits in a single metal layer of the integrated circuit. In another embodiment, the interface circuit may be implemented using a hardware configurable bi-directional interface buffer circuit.

Adjustable interface buffer circuit between a programmable logic device and a dedicated device

An implementation of an apparatus and method to generate a dynamically controlled clock is provided. The resulting clock reduces otherwise produced narrow clock pulses and allows for control from two separate control signals. A first control signal indicates a low power mode, for example a chip-wide low power mode. A second control signal indicates a user-selected mode to shutdown a selected clock.

Dynamic clock control

In accordance with the invention, a serializer/deserializer core of a field programmable gate array includes a channel clock and a data channel. The data channel can serialize and deserialize data in two modes. In the first mode, an embedded clock signal is recovered from the data. In the second mode, a clock signal is provided by the channel clock. A selection signal determines in which mode each of the data channels in the serializer/deserializer core operates. An stair-step clock generator generates a series of rising edge signals used to serialize and deserialize data. The number of bits serialized and deserialized is determined by the control signals to a set of multiplexers in the stair-step clock generator which determine how many registers in the stair-step clock generator are activated.

Growing community of inventors

Los Gatos, CA, United States of America

Senani Gunaratna