Abstract: Multiple damascene layers in integrated circuits can form several advantageous designs or components that may lower cost or increase performance of certain designs. In embodiments for power bus signals, multiple damascene layers may be used to form traces with increased power capacity and lower cost. In other embodiments, multiple damascene layers may be used to form components such as capacitors and inductors with increased performance.

Abstract: A method for designing and mapping a power-bus grid in an integrated circuit. A floor plan is created by mapping wire segments of the power-bus grid to various metal layers of the IC core. Power zones which specify the current consumption of analog, digital, and memory block regions are also mapped to the IC core. A netlist of the floor plan design is generated and simulated, with the simulation returning current density and a voltage drop values in the wire segments with respect to the power zones. Calculated current density and voltage drop values are analyzed using a color map to indicate the current density and voltage drop levels of the wire segments. Power-bus wire segments are displayed in colors matched to the current density and voltage drop levels in the color map, helping the designer identify potential electromigration and voltage drop problems. The floor plan design can be modified if the calculated density and voltage drop values indicate potential electromigration or voltage drop problems.

Abstract: Relevant logic cells and waveforms of a circuit are automatically identified, traced and displayed by using conventional simulation, schematic viewing and waveform viewing tools. The input and output waveforms to and from each logic cell and a transition and a transition time point of each waveform are derived. The output waveform and a selected transition time point identify a predictive input waveform and its transition time which cause the output signal transition at the selected transition time point. The predictive input signal is the output signal of a preceding, predictive logic cell, thereby identifying the preceding predictive logic cell. Repetitions of this procedure are performed with each new identified predictive logic cell to automatically derive a series or logic cone of cells. A different logic cone is derived for each of the multiple failing output signals at output pads.

Abstract: A method for analyzing an electrical characteristic of wire segments configured as one or more power meshes in an integrated circuit (IC) core comprising the steps of (A) specifying design information corresponding to the power meshes, (B) specifying at least one type of analysis to be performed, where the analysis comprises (i) generating a file corresponding to the IC core in a format compatible with an electronic circuit simulator and (ii) calculating the electrical characteristic of the wire segments via the circuit simulator, and (C) displaying the calculated electrical characteristic.

Abstract: A clock tree uses a temporary clock buffer or reference signal in a clock tree deskew circuit to dynamically minimize skew in a variable delay clock signal that synchronizes operation of synchronized circuit components of an integrated circuit. Skew between the temporary clock buffer signals are minimized by providing identical path lengths and path geometries. The clock tree deskew circuit reduces the clock tree skew in repeated intervals over a period of time. When the tree deskew circuit is deskewed for a multilevel clock tree, the temporary clock net of that level of the clock tree deskew circuit is then turned off to prevent unnecessary further adjustments to the clock signals, but can be turned back on when conditions change that alter the clock tree skew. The clock tree deskew circuit adjusts the variable delay clock buffer signal of each pair toward the temporary clock buffer signal of the pair to reduce the skew between the two clock buffer signals.

Abstract: The subject matter described herein involves a wire bonded integrated circuit (IC) that includes a power distribution grid, or power redistribution bus, within a single layer, e.g. the topmost metallization layer, of the IC chip. Electrical conductors in the power distribution grid are generally L-shaped. Thus, the electrical conductors are arranged generally in symmetrical quadrants within which the electrical conductors extend from one side edge of the IC chip to a generally right-angled corner and then to a second side edge that is adjacent to the first side edge.

Abstract: Relevant logic cells and waveforms of a circuit are automatically identified, traced and displayed by using conventional simulation, schematic viewing and waveform viewing tools. The input and output waveforms to and from each logic cell and a transition and a transition time point of each waveform are derived. The output waveform and a selected transition time point identify a predictive input waveform and its transition time, which cause the output signal transition at the selected transition time point. The predictive input signal is the output signal of a preceding, predictive logic cell, thereby identifying the preceding predictive logic cell. Repetitions of this procedure are performed with each new identified predictive logic cell to automatically derive a series or cone of logic cells which cause the desired output signal at a selected output signal transition time.

Abstract: Multiple damascene layers in integrated circuits can form several advantageous designs or components that may lower cost or increase performance of certain designs. In embodiments for power bus signals, multiple damascene layers may be used to form traces with increased power capacity and lower cost. In other embodiments, multiple damascene layers may be used to form components such as capacitors and inductors with increased performance.

Abstract: A method for analyzing electromigration and voltage drop effects in wire segments forming a power-bus grid of an integrated circuit. A floor plan design is created by mapping wire segments to various metal layers in the IC core. Digital, analog, and memory power zones indicating the power consumption of regions within the core and are also mapped to the core. An equivalent circuit of the floor plan, including a resistor array and current sources is generated in a netlist. The netlist is simulated, with the current density and voltage drop of power-bus wire segments calculated. Calculated current density and voltage drop values are analyzed in the floor plan design using a color map to indicate the current density and voltage drop levels of the wire segments. Power-bus wire segments are displayed in colors matched to the current density and voltage drop levels in the color map, helping the designer identify potential electromigration or voltage drop problems.

Abstract: A clock tree uses a temporary clock buffer or reference signal in a clock tree deskew circuit to dynamically minimize skew in a variable delay clock signal that synchronizes operation of synchronized circuit components of an integrated circuit. Skew between the temporary clock buffer signals are minimized by providing identical path lengths and path geometries. The clock tree deskew circuit reduces the clock tree skew in repeated intervals over a period of time. When the tree deskew circuit is deskewed for a multilevel clock tree, the temporary clock net of that level of the clock tree deskew circuit is then turned off to prevent unnecessary further adjustments to the clock signals, but can be turned back on when conditions change that alter the clock tree skew. The clock tree deskew circuit adjusts the variable delay clock buffer signal of each pair toward the temporary clock buffer signal of the pair to reduce the skew between the two clock buffer signals.

Abstract: Relevant logic cells and waveforms of a circuit are automatically identified, traced and displayed by using conventional simulation, schematic viewing and waveform viewing tools. The input and output waveforms to and from each logic cell and a transition and a transition time point of each waveform are derived. The output waveform and a selected transition time point identify a predictive input waveform and its transition time, which cause the output signal transition at the selected transition time point. The predictive input signal is the output signal of a preceding, predictive logic cell, thereby identifying the preceding predictive logic cell. Repetitions of this procedure are performed with each new identified predictive logic cell to automatically derive a series or logic cone of cells.

Abstract: A clock tree deskew circuit dynamically minimizes skew in clock signals that synchronize operation of synchronized circuit components of an integrated circuit. The clock tree deskew circuit reduces the clock tree skew in repeated intervals over a period of time. The clock tree deskew circuit is then turned off to prevent unnecessary further adjustments to the clock signals, but can be turned back on when conditions change that alter the clock tree skew. The clock signals are paired together in a continuous loop such that each clock signal is the first clock signal of the pair when paired with the next clock signal and is the second clock signal when paired with the one before it. The clock tree deskew circuit detects the absolute skew between each pair of the clock signals. The clock tree deskew circuit adjusts the first clock signal of each pair toward the second clock signal of the pair to reduce the skew between the two clock signals.

Abstract: A multilevel clock tree uses a temporary clock buffer or reference signal in a clock tree deskew circuit to dynamically minimize skew in a variable delay clock signal that synchronizes operation of synchronized circuit components of an integrated circuit. There are multiple temporary clock buffer signals at each level of the multilevel clock tree. Skew between the temporary clock buffer signals are minimized by providing identical path lengths and path geometries at each level of the temporary clock buffer. The clock tree deskew circuit reduces the clock tree skew, on a level by level basis, in repeated intervals over a period of time. When each level of the tree deskew circuit is deskewed, that level of the clock tree deskew circuit is then turned off to prevent unnecessary further adjustments to the clock signals, but can be turned back on when conditions change that alter the clock tree skew.

Abstract: A multilevel clock tree uses a temporary clock buffer or reference signal in a clock tree deskew circuit to dynamically minimize skew in a variable delay clock signal that synchronizes operation of synchronized circuit components of an integrated circuit. There are multiple temporary clock buffer signals at each level of the multilevel clock tree. Skew between the temporary clock buffer signals are minimized by providing identical path lengths and path geometries at each level of the temporary clock buffer. The clock tree deskew circuit reduces the clock tree skew, on a level by level basis, in repeated intervals over a period of time. When each level of the tree deskew circuit is deskewed, that level of the clock tree deskew circuit is then turned off to prevent unnecessary further adjustments to the clock signals, but can be turned back on when conditions change that alter the clock tree skew.

Abstract: A metastability risk simulation analysis device and method for identifying metastability risks of a design. The metastability risk simulation analysis device includes computer readable code which is configured to analyze simulation information relating to the design and determine whether the design presents a metastability risk. Desirably, the computer readable code is configured to determine whether two signals, such as a data signal and a clock signal of a synchronous element of the design, cross over each other thereby presenting a metastability risk, and is configured to generate a summary report identifying those synchronous elements of the design which present a metastability risk.

Abstract: The slew rate of a digital logic output signal delivered from an output pad of an integrated circuit is controlled relative to a load connected to the output pad. At least two pluralities of trigger signals at sequentially spaced time intervals are generated, and the time intervals between the first and second trigger signals or the temporal occurrence of the first and second trigger signals in relation to the load connected to the output pad is selected to change the slew rate of the output signal. The timing of the plurality of trigger signals is established in relation to an input signal to which the driver circuit responds and in relation to the change in the output signal with time as influenced by the load connected to the output pad.

Abstract: An integrated circuit includes a substrate of semiconductor material having a periphery and a geometric center, a plurality of circuits formed on the substrate, and a power bus grid electrically coupled to the plurality of circuits. The power bus grid is formed of a plurality of power bus straps having a strap density that progressively varies with distance from the geometric center toward the periphery.

Abstract: A clock tree deskew circuit dynamically minimizes skew in clock signals that synchronize operation of synchronized circuit components of an integrated circuit. The clock tree deskew circuit reduces the clock tree skew in repeated intervals over a period of time. The clock tree deskew circuit is then turned off to prevent unnecessary further adjustments to the clock signals, but can be turned back on when conditions change that alter the clock tree skew. The clock signals are paired together in a continuous loop, such that each clock signal is the first clock signal of the pair when paired with the next clock signal and is the second clock signal when paired with the one before it. The clock tree deskew circuit detects the absolute skew between each pair of the clock signals. The clock tree deskew circuit adjusts the first clock signal of each pair toward the second clock signal of the pair to reduce the skew between the two clock signals.

Abstract: A power bus grid architecture for an integrated circuit including a plurality of main bars assembled along the perimeter of the grid and a plurality of bus bars assembled within the perimeter of the grid. The bus bars are each composed of a plurality of segments with each segment having a substantially constant width. Each segment on certain bus bars has a different width from the next adjacent segment. The width of a particular segment is determined by the distance of the segment from the nearest main power bar. Because the current flow through the segments nearest to the main power bar tends to be greater than the current flow through the segments further from the main power bar, the segments nearest to the main power bar can be made much wider than the segments furthest from the main power bar without significant deleterious effects to the circuit from voltage drops or electromigration.

Abstract: A meta-hardened circuit that reduces the effects of metastability preferably includes a pulse generator coupled to receive a first clock signal and generate in response thereto a second clock signal and an enable signal. A buffer, preferably tri-state, is coupled to receive a first data signal and the enable signal and generate in response thereto a second data signal. A bi-stable device, such as a flip-flop, is coupled to receive the second clock signal and the second data signal. The pulse generator preferably includes a combining device and a delay device. The buffer preferably includes at least one tri-state inverter and a keeper circuit. A method to reduce the metastability effects preferably includes the step of generating a delay between a second data input signal and a second clock signal that is greater than a delay between a first data input signal and a first clock signal. The step of generating preferably occurs in one clock cycle.