Xilinx, Inc.

Sean W Kao

Arifur Rahman

Tim Tuan

James B Anderson

Patrick J Crotty

Satyaki Das

Jinsong Oliver Huang

Sathaki Das

Leakage current reduction from a logic block is implemented via power gating transistors that exhibit increased gate oxide thickness as compared to the thin-oxide devices of the power gated logic block. Increased gate oxide further allows increased gate to source voltage differences to exist on the power gating devices, which enhances performance and reduces gate leakage even further. Placement of the power gating transistors in proximity to other increased gate oxide devices minimizes area penalties caused by physical design constraints of the semiconductor die.

Method and apparatus for leakage current reduction

A hardware stack (HSTACK) structure using programmable logic can include a look-up table (LUT) random access memory (RAM) circuit and circuitry within the LUT RAM circuit for propagating data upwards and downwards. The hardware structure can be arbitrarily assembled into a larger structure by adding stacks to a top portion, a bottom portion, or a portion between the top portion and the bottom portion. The hardware stack structure can further include a virtual stack (VSTACK) structure coupled to the HSTACK structure within a field programmable gate array (FPGA) fabric. The VSTACK can be arranged in the form of an appended peripheral memory and cache control for virtual extension to an HSTACK address space. The hardware stack structure can further include an auxiliary reset circuit.

Hardware stack structure using programmable logic

A PLD () includes a power management unit (PMU) that selectively implements one or more different power-reduction techniques in response to power configuration signals (PC). By manipulating the PC signals, the PMU can independently enable/disable various supply voltage circuits () that power CLBs (), IOBs (), and configuration memory cells (), can generate a capture signal that causes data stored in storage elements of the CLBs to be captured in configuration memory cells, and/or can switch power terminals of configuration memory cells between voltage supply circuits. Also, the PMU can sequentially apply and remove power from a number of configurable PLD portions in response to the PC signals, wherein each configurable portion may include any number of the PLD's resources.

Implementation of low power standby modes for integrated circuits

Power-gating circuit resources of an integrated circuit is described. The circuit resources are associated into sets responsive to utilization levels. The associating includes providing a first set of the sets, a first number of the circuit resources in the first set being associated with a first level of utilization. The associating also includes providing a second set of the sets, a second number of the circuit resources in the second set being associated with a second level of utilization. The first number is less than the second number responsive to the first level of utilization being greater than the second level of utilization. The circuit resources of the first set are commonly coupled to a reference voltage level via a first gating circuit. The circuit resources of the second set are commonly gated to the same or a different reference voltage level via a second gating circuit.

Power gating various number of resources based on utilization levels

A circuit for enabling partial reconfiguration of memory elements of a device having programmable logic is described. The circuit comprises a block of memory cells comprising a look-up table of a configurable logic block; and a reset signal coupled to the block of memory elements, the reset signal enabling partial reconfiguration of the memory cells of the configurable logic block. Each the memory cell may be coupled to receive the reset signal enabling the partial reconfiguration of the block of memory cells of the configurable logic block. The reset signal may comprise a plurality of signals, wherein each signal of the plurality of signals is coupled to a memory cell of the block of memory cells. Each memory cell may also receive a signal for setting an initial state. A method of enabling partial reconfiguration of memory cells of a look-up table of a programmable logic device is also described.

Circuit for and method of enabling partial reconfiguration of a device having programmable logic

A PLD utilizes a heterogeneous architecture to reduce power consumption of its active resources. The PLD's programmable resources are divided into a first partition and a second partition, where the resources of the first partition are optimized for low power consumption and the resources of the second partition are optimized for high performance. Portions of a user design containing non-critical timing paths are mapped to and implemented by the resources of the power-optimized first partition, and portions of the user design containing critical timing paths are mapped to and implemented by the resources of the performance-optimized second partition.

Structures and methods for heterogeneous low power programmable logic device

An FPGA system includes a combined shift register and look up table (LUT) forming a shift register LUT (SRL) that provides data write, reset and shift enable on a cell-by-cell basis. The data write and reset can be performed during FPGA operation without requiring a number of frames or columns of configuration memory cells to be reprogrammed, as with conventional SRAM cells. The shift enable provides for synchronization to facilitate the cell-by-cell write and reset.

Writeable shift register lookup table in FPGA with SRAM memory cells in lookup table reprogrammed by writing after initial configuration

An apparatus is disclosed that may reduce the dynamic power dissipation of a configurable IC device such as an FPGA by reducing the peak-to-peak voltage swing of signals transmitted over the device's interconnect signal lines without including additional level shifter circuits. For some embodiments, existing multiplexing circuit architectures provided within logic resources of various logic blocks of the configurable IC device may be used as level shifter circuits to increase the voltage swing of signals received into the blocks from the interconnect signal lines, and modified multiplexing circuit architectures provided within the logic resources may be used to reduce the voltage swing of signals output from the logic blocks onto the interconnect signal lines.

Low-swing interconnections for field programmable gate arrays

The present invention incorporates level-shifting functions within a multiplexer circuit that may be implemented in IC devices having low and high voltage domains. The multiplexer circuit utilizes pseudo-differential multiplexing architectures and employs level-shifting techniques to convert low-voltage signals received from the low-voltage domain into high-voltage signals more suitable for controlling the propagation of a selected input signal through the pass gates of the multiplexer circuit. For some embodiments, some of the select signals may be decoded to generate a number of decoded select signals that can be used to control the selective routing of signals through the multiplexer.

Level-shifting pass gate multiplexer

A configurable latch is implemented using a configurable pulse generator and a level sensitive (LS) latch. The configurable pulse generator produces either a pulse signal that is aligned with the input clock edge, or simply provides the input clock signal to its output in response to a pulse generator control signal. If a pulse signal is provided to the latch, then edge triggered (ET) latch operation is effected within the latch. If, on the other hand, a clock signal is provided to the latch, then LS latch operation is effected within the latch. Thus, configuration of latch operation is established in response to the type of clock signal that is provided to the latch.

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Campbell, CA, United States of America

Sean W Kao