Method of selecting device threshold voltages for high speed and low power
First Claim
1. A computer implemented method of selecting a device threshold voltage, comprising the steps of:
- identifying a critical path through a circuit;
selecting devices in said critical path according to a predetermined cost function to adjust the threshold voltage of at least one of the selected devices, wherein the cost function includes at least two components, a first component dependent on process parameters and a second component dependent on design specific parameters; and
adjusting the threshold voltage of said at least one of the selected devices in said critical path to meet predetermined timing criteria.
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Accused Products
Abstract
A method of selecting device (14-16, 18-24, 28-30) threshold voltages for high speed and low overall power involves identifying (42) the critical paths by predetermined timing criteria. All transistors have an initial, typically high, threshold voltage (40). Transistors outside the critical paths keep the initial high threshold voltages to minimize static power drain. The transistors in the critical path are selected (43) according to a predetermined sorting function to have a low threshold voltage and thereby switch faster. Although the lower threshold voltage devices consume more static power in standby mode, the power drain is accepted as a trade-off in favor of increased speed through the critical path. The supply voltage is reduced to minimize dynamic power. The integrated circuit is thus optimized to run at a higher frequency with lower overall power consumption.
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Citations
19 Claims
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1. A computer implemented method of selecting a device threshold voltage, comprising the steps of:
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identifying a critical path through a circuit; selecting devices in said critical path according to a predetermined cost function to adjust the threshold voltage of at least one of the selected devices, wherein the cost function includes at least two components, a first component dependent on process parameters and a second component dependent on design specific parameters; and adjusting the threshold voltage of said at least one of the selected devices in said critical path to meet predetermined timing criteria. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A computer implemented method of selecting a device threshold voltage, comprising the steps of:
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providing a netlist of devices in a circuit each including an initial threshold voltage; identifying a critical path through said circuit; selecting devices in said critical path according to a predetermined cost function to adjust the initial threshold voltage, wherein the cost function includes at least two components, a first component dependent on process parameters and a second component dependent on design specific parameters; and adjusting the threshold voltage of said selected devices in said critical path to meet predetermined timing criteria. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
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17. An apparatus for selecting a device threshold voltage, comprising:
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means for identifying a critical path through a circuit; means for selecting devices in said critical path according to a predetermined cost function to adjust a threshold voltage of at least one selected device, wherein the cost function includes at least two components, a first component dependent on process parameters and a second component dependent on design specific parameters; and means for adjusting the threshold voltage of said at least one selected device in said critical path to meet predetermined timing criteria. - View Dependent Claims (18, 19)
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Specification