455 results about "Power gating" patented technology

Field Programmable Logic Arrays (FPGAs) are described which utilize multiple power supply voltages to reduce both dynamic power and leakage power without sacrificing speed or substantially increasing device area. Power reduction mechanisms are described for numerous portions of the FPGA, including logic blocks, routing circuits, connection blocks, switch blocks, configuration memory cells, and so forth. Embodiments describe circuits and methods for implementing multiple supplies as sources of Vdd, multiple voltage thresholding Vt, signal level translators, and power gating of circuitry to deactivate portions of the circuit which are inactive. The supply voltage levels can be fixed, or programmable. Methods are described for performing circuit CAD in the routing and assignment process on FPGAs, in particular for optimizing FPGA use having the power reduction circuits taught. Routing methods describe utilizing slack timing, power sensitivity, trace-based simulations, and other techniques to optimize circuit utilization on a multi Vdd FPGA.

A power gated semiconductor integrated circuit comprises: (1) logic circuit to be power gated, said logic circuit having a virtual ground rail; (2) footer device disposed between said virtual ground rail and a ground rail for reducing power consumption of said logic circuit; and (3) virtual rail voltage clamp disposed electrically in parallel with said footer device for limiting the voltage at the virtual ground rail, the virtual rail voltage clamp comprising at least one NFET. A total of Nf NFETs are connected to the virtual ground rail of the integrated circuit for use as both virtual rail voltage clamps and footer devices. A quantity of Nmax-VC NFETs are scanned and perform the function of voltage clamps and the remaining (Nf−Nmax-VC) NFETs perform power gating. Manufacturing variability immunity and tuning of the variability immunity is achieved by adjusting the quantity Nmax-VC based upon testing of the manufactured integrated circuit.

A method of power gating a latch including detecting a state of the latch, detecting a power gate signal, providing power to the latch while the power gate signal is negated, and removing power from the latch when the power gate signal is asserted and the latch is in a predetermined state. The method may include any one or more of pulling a node of the latch to a selected state while the power gate signal is asserted to ensure that the latch powers up in the predetermined state, providing a signal indicative of the latch state and the power gate signal to respective inputs of a logic gate having an output indicative thereof, switching a supply voltage to a power input of the latch based on a state of the output of the logic gate, and closing a switch to pull a node of the latch low.

A method and a structure provide a space efficient integrated circuit using standard cells and power gating by switch cells. The standard cells may be tapless, i.e., not provided a substrate connection to a power supply or ground rail by a tap within the cell. The substrate connection for these standard cells may be provided by the switch cells or by specialized tap cells. The tapless standard cells may include only a context-sensitive rail, which may be configured to be a virtual ground rail by a power gating connection to a switch cell or by a direct connection to a power supply or ground rail.

A method extends a clock-gating technique to provide a sleep signal for controlling switch circuits that reduce active leakage power. Using this extension of the clock-gating technique, fine-grained power-gating is achieved. The method automatically identifies, at an RTL or a gate level, the logic circuits that can be power-gated. The method of the present invention derives a sleep signal for fine-grained power-gating that may be applicable to both time-critical and non-time-critical designs.