Apple Inc.

Transmeta Corporation

Other

Shingo Suzuki

Toshinari Takayanagi

Bo Tang

Karthik Rajagopal

James B Burr

Victor Zyuban

Conrad Havluj Ziesler

Rajat Goel

Edvin Catovic

Vincent R Von Kaenel

Ajay Bhatia

Mohamed Hassan Abu-Rahma

Greg M Hess

Daniel C Murray

Pradeep Kanapathipillai

Richard F Russo

Harsha Krishnamurthy

Jaroslav Raszka

Shahzad Nazar

Amrinder S Barn

Matthew R Johnson

Manoj Gopalan

Raghava Rao V Denduluri

Jung-Cheng Yeh

Pankaj Lnu

Robert E Lamburn, Jr

Neehar Jandhyala

Robert E Lamburn

A power switch control circuit is disclosed. A sensor circuit may determine a leakage current of a power switch coupled to a power supply signal and a power terminal of a circuit block. The power switch may be configured to selectively couple or decouple the circuit block from the power supply signal using a switch control signal. The switch control circuit may, in response to receiving a request to open the power switch, determine a target voltage level that is greater than a voltage level of the power supply signal for the switch control signal using the leakage current, and transition the switch control signal from an initial voltage to the target voltage level.

Low leakage power switch

A method and apparatus for distributing power in an integrated circuit (IC) is disclosed. The IC includes at least one electrically conductive bump coupled to a true voltage node. Power may be distributed to the IC from an external power source coupled to the bump. The integrated circuit further includes a virtual voltage node. A power switch may be implemented, with the power switch being located directly beneath the bump. A first vertical connector may couple one portion of the power switch to the bump, while a second vertical conductor may couple another portion of the switch to the virtual voltage node.

Method and apparatus for power distribution in integrated circuits

A processor includes an instruction issue circuit, and high-utilization and low-utilization execution unit circuits coupled to execute instructions received from the instruction issue unit. On average, utilization of the low-utilization execution unit circuit is lower than utilization of the high-utilization execution unit circuit. The processor also includes a retention circuit coupled to a different power domain than the low-utilization execution unit circuit, and a power management circuit. The power management circuit may be configured to detect that inactivity of the low-utilization execution unit circuit satisfies a threshold inactivity level; upon detecting that the threshold inactivity level is satisfied, cause architecturally-visible state of the low-utilization execution unit circuit to be copied to the retention circuit; and subsequent to copying of the architecturally-visible state to the retention circuit, cause the low-utilization execution unit circuit to enter a power-off state, where the retention circuit retains stored data during the power-off state.

Execution unit power management

Techniques are disclosed relating to generating an overdrive voltage for power switch circuitry. In some embodiments, the value of the overdrive voltage is adjusted dynamically in order to reduce leakage current during power gating. In some embodiments, an apparatus includes a power switch circuit element configured to gate power to circuitry in the apparatus based on a control signal. In some embodiments, the power switch circuit element is powered by a supply voltage. In some embodiments, the apparatus also includes control circuitry configured to generate the control voltage at a different voltage level than the supply voltage, based on comparison of leakage current of ones of a plurality of replicas of the power switch circuit element. In some embodiments, the replicas are configured to receive different reference voltages as respective replica control signals. In various embodiments, the disclosed techniques may generate overdrive voltages that reduce leakage current during power gating.

Generating an overdrive voltage for power switch circuitry

A method of generating an area efficient power switch cell includes receiving, by a cell library design tool, a specification of a power switch circuit to be established as a power switch cell in a cell library. The cell library design tool also receives one or more attributes of the power switch cell including a height of the cell boundary and receiving, by the cell library design tool, a layout placement constraint requiring the power switch cell to be placed in a semiconductor layout so as to bridge two parallel rows of doped wells. The parallel rows of doped wells are interleaved with doped substrate and the doping of the wells is of a different type than that of the substrate. Based on the specification of the power switch circuit, the one or more attributes, and the layout placement constraint, the cell library design tool generates the power switch cell.

Area efficient power switch

In an embodiment, an integrated circuit may include one or more power gated blocks and a power manager circuit. The power manager circuit may be configured to generate a block enable for each power gated block and a block enable clock. The power gated block may generate local block enables to various power switch segments in the power gated block. In particular, the power gated block may include a set of series-connected flops that receive the block enable from the power manager circuit. The power gated block may include a set of multiplexors (muxes) that provide the local block enables for each power switch segment. One input of the muxes is coupled to the block enable, and the other input is coupled to another enable propagated through one of the other power switch segments. Accordingly, the muxes may be controlled to select the propagated enables or the input block enable.

Power switch ramp rate control using selectable daisy-chained connection of enable to power switches or daisy-chained flops providing enables

A method an apparatus for a power switch acceleration scheme during wakeup is disclosed. In one embodiment, an integrated circuit includes at least one power gated circuit block. The power gated circuit block includes a virtual voltage node from which a voltage is provided to the circuitry of the block when active. Power switches are coupled between the virtual voltage node and a corresponding global voltage node. When the power gated circuit block is powered on, power switches are activated sequentially. The rate at which power switches are activated is increased as the voltage on the virtual voltage node increases. Sequentially activating the power switches may prevent an excess of current inrush into the power gated circuit block. The increase in the rate at which power switches are activated when the voltage on the virtual voltage node is at least at a certain level may allow for a faster wakeup.

Power switch acceleration scheme for fast wakeup

A multi-path power switch scheme for functional block wakeup is disclosed. The scheme may be applied to functional blocks of an integrated circuit. When a power on procedure is initiated within a given functional block, a first group of power switches in a functional block may be powered on, while a second group of power switches is inhibited from powering on. After a predetermined time has elapsed, activation of the second group of power switches is initiated. After initiation of a power up procedure for a given functional block, the powering up of a second functional block to be powered on may initially be inhibited. After a predetermined time has elapsed, the powering on of the second functional block may be initiated. Overlap between times when the first and second groups of switches are active may depend on process, voltage, and temperature variations.

Multi-path power switch scheme for functional block wakeup

In one embodiment, a configurable power switch cell methodology may include designing multiple power switch cells which may be assembled to form a set of power switches such as a power switch segment. The power switch cells may all be designed to occupy the same amount of integrated circuit area, in an embodiment. Accordingly, one cell may be readily replaced by another, even late in the design process, without disturbing the placement of surrounding circuitry. In an embodiment, the power switch cells may include the interconnect layers that connect between cells, and abutting the power switch cells may automatically connect the interconnect between cells. Accordingly, swapping one power switch cell for another may be accomplished by placing the cell. No routing work may be required.

Configurable power switch cells and methodology

In an embodiment, an integrated circuit includes a power gated block and a power manager circuit. The power manager circuit is configured to provide a block enable signal and at least one select signal to the power gated block. The power manager may generate the select signal responsive to various parameters that affect the speed of the integrated circuit, such as power supply voltage magnitude, operating temperature, and/or process corner. The power gated block may control the rate at which power switches are enabled based on the select signal or signals. For example, the power switches may be enabled in a more parallel or more serial fashion and/or the drive strength of block enable buffering to the power switches may be varied. In another embodiment, the power manager circuit may assert multiple block enables to the power gated block (which are connected to separate sets of power switches), and may control the timing of assertion of the enables to control the rate at which power switches are enabled.

Power switch ramp rate control using programmable connection to switches

In an embodiment, an integrated circuit may include one or more power managed blocks and a power manager circuit. The power manager circuit may be configured to generate a block enable for each power managed block and a block enable clock. The power managed block may generate local block enables to various power switches in the power managed block, staggering the block enables over two or more block enable clock cycles. In particular, the power managed block may include a set of series-connected flops that receive the block enable from the power manager circuit. The output of each flop may be coupled to a respective set of power switches and may enabled those switches. The change in current flow due to enabling and/or disabling the power managed block may thus be controlled. In an embodiment, the frequency of the block enable clock may be set to a defined value independent of process, voltage, and temperature conditions in the integrated circuit.

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San Jose, CA, United States of America

Shingo Suzuki