US 7,627,844 B2 · Methods and apparatuses for transient analyses of circuits

Abstract

Methods and apparatuses for transient analyses of a circuit using a hierarchical approach. In one embodiment, the cells are grouped locally on the power supply network according to average power dissipation. A time varying current of each cell group is estimated using a probabilistic approach to represent the cell group so that the probability of a more severe waveform for the current of the cell group is under a certain level. For example, the cells in a group are partitioned as switching cells and non-switching cells using cell toggle rates for the determination of the time varying current. The circuit model of the power supply network includes the current sources according to the estimated time varying currents for the cell groups, the power supply wire resistance, the power supply to ground wire capacitance, well capacitance and the de-coupling capacitance from non-switching cells.

Claims27

Dependent claims

A machine implemented method for circuit analysis, the method comprising:

determining, through a processor, a representation of a first current, drawn by a group of cells from a power supplying network of a circuit in a clock cycle, using data indicating probabilities of state switching at the cells of the group that includes determining a first number of cells from the group of cells that switch together in a same clock cycle, the representation of the first current specifying the first current as a non-constant function of time in the clock cycle, wherein the first number of the cells is determined from the data indicating probabilities of state switching at the cells of the group such that a probability of more than the first number of cells of the group switching in the same clock cycle is about a predetermined value;
and wherein the determining the representation of the first current comprises
selecting first cells of the first number from the group to determine the representation of the first current from currents drawn by the first number of the first cells when the first cells switch together in the same clock cycle and wherein said determining the representation of the first current further comprises
determining a representation of a second current, drawn by one of the cells of the group.

1 more element

A machine readable medium containing executable computer program instructions which when executed by a data processing system cause said system to perform a method for circuit analysis, the method comprising:

determining a representation of a first current, drawn by a group of cells from a power supplying network of a circuit in a clock cycle, using data indicating probabilities of state switching at the cells of the group that includes determining a first number of cells from the group of cells that switch together in a same clock cycle, the representation of the first current specifying the first current as a non-constant function of time in the clock cycle, wherein the first number of the cells is determined from the data indicating probabilities of state switching at the cells of the group such that a probability of more than the first number of cells of the group switching in the same clock cycle is about a predetermined value;
and wherein the determining the representation of the first current comprises
selecting first cells of the first number from the group to determine the representation of the first current from currents drawn by the first number of the first cells when the first cells switch together in the same clock cycle and wherein said determining the representation of the first current further comprises
determining a representation of a second current, drawn by one of the cells of the group.

1 more element

A date processing system for circuit analysis, the data processing system comprising:

means for determining a representation of a first current, drawn by a group of cells from a power supplying network of a circuit in a clock cycle, using data indicating probabilities of state switching at the cells of the group that includes means for determining a first number of cells from the group of cells that switch together in a same clock cycle, the representation of the first current specifying the first current as a non-constant function of time in the clock cycle, wherein the first number of cells is determined from the data indicating probabilities of state switching at the cells of the group such that a probability of more than the first number of cells of the group switching in the same clock cycle is about a predetermined value;
and wherein the determining the representation of the first current comprises
means for selecting first cells of the first number from the group to determine the representation of the first current from currents drawn by the first number of the first cells when the first cells switch together in the same clock cycle and wherein said means for determining the representation of the first current further comprises
means for determining a representation of a second current, drawn by one of the cells of the group.

1 more element

Dependencies are inferred from the claim text.

Methods and apparatuses for transient analyses of circuits

Life of this patent

Methods and apparatuses for transient analyses of circuits

Life of this patent

Abstract

Claims27