摘要:
A method, system and computer program product for analyzing and modifying a static timing slack of a timing path in a static timing analysis of a design of an integrated circuit (IC) with a transient power supply are disclosed. A static timing slack analysis is performed at a selected endpoint in an IC to obtain a candidate timing path leading to the endpoint with a worst static timing slack. A transient static timing slack is determined for the candidate timing path for each clock cycle of a clock signal under the transient power supply. The determined transient static timing slack is used to adjust the timing of the IC and to modify the static timing slack of the candidate timing path.
摘要:
A method and service of balancing delay in a circuit design begins with nodes that are to be connected together by a wiring design, or by being supplied with an initial wiring design that is to be altered. The wiring design will have many wiring paths, such as a first wiring path, a second wiring path, etc. Two or more of the wiring paths are designed to have matching timing, such that the time needed for a signal to travel along the first wiring path is about the same time needed for a signal to travel along the second wiring path, the third path, etc. The method/service designs one or all of the wiring paths to make the paths traverse wire segments of about the same length and orientation, within each wiring level that the first wiring path and the second wiring path traverse. Also, this process makes the first wiring path and the second wiring path traverse the wire segments in the same order, within each wiring level that the first wiring path and the second wiring path traverse.
摘要:
A method for incrementally calculating the impact of coupling noise on the timing of an integrated circuit (IC) having a plurality of logic stages by performing an initial timing analysis on the IC to provide a first determination of the impact of coupling noise on the timing. One or more design changes to the IC are then performed. In response to the design change, the impact of the coupling noise to the timing is calculated on the logic stage where the change was made and on the logic stages downstream thereof. The results of the calculations are then inputted to a timing analysis tool to adjust the delay and slew of each logic stage where the design change was made and to the logic stages downstream thereof.
摘要:
A method of performing node-based static timing analysis on a digital network and a program storage device for implementing the method, wherein the method comprises partitioning timing delays in the digital network into portions attributable to a factor of interest and portions attributable to other factors; multiplying the timing delays by different weights based on the factor of interest to produce weighted timing delays; and using the multiplied timing delays to determine a relative impact of the factor of interest on the various paths in the digital network. The method further comprises setting arrival times of timing signals at digital network path start points to zero and identifying digital network paths whose timing delays are dominated by a particular factor of interest. The different weights comprise any of a positive weight, a negative weight, and a zero weight.
摘要:
An electrical wiring structure and method of designing thereof. The method identifies at least one wire pair having a first wire and a second wire. The second wire is already tri-stated or can be tri-stated. The wire pair may have a same-direction switching probability per clock cycle that is no less than a predetermined or user-selected minimum same-direction switching probability. Alternatively, the wire pair may have an opposite-direction switching probability per clock cycle that is no less than a predetermined or user-selected minimum opposite-direction switching probability. The first wire and the second wire satisfy at least one mathematical relationship involving: a spacing between the first wire and the second wire; and a common run length of the first wire and the second wire.
摘要:
A hybrid linear wire model for tuning the transistor widths of circuits linked by RC interconnects is described. The method uses two embedded simulators during the tuning process on netlists that contain resistors (Rs). A Timing oriented simulator is used only for timing purposes on the original netlist that includes all the Rs. A Gradient oriented simulator is then run only on the modified netlist with all Rs shorted and within the iterative loop of the tuner to compute gradients. The present hybrid method achieves a significant improvement in computational speed. The Timing oriented simulator is fast and accurate for only timing netlists with Rs, but cannot compute gradients efficiently. The Gradient oriented simulator computes gradients efficiently but cannot do so in the presence of Rs. To prevent “de-tuning” that typically occurs when all Rs are shorted, ‘wire-adjusts’ are provided that make the initial timing results using the Gradient oriented simulator on the shorted netlist match the timing results using Timing oriented simulator on the original netlist. This permits the optimizer sense initially the correct set of critical timing paths, and more significantly, it permits the wire-adjusts keep track of the changing transistor widths to guide the optimizer during the iterations until convergence is achieved.
摘要:
A differential sinusoidal signal pair is generated on an integrated circuit (IC). The differential sinusoidal signal pair is distributed to clock receiver circuits, which may be differential amplifiers. The clock receiver circuits receive the differential sinusoidal signal pair and convert the differential sinusoidal pair to local clock signals. Power consumption and noise generation are reduced as compared to conventional clock signal distribution arrangements.
摘要:
A differential sinusoidal signal pair is generated on an integrated circuit (IC). The differential sinusoidal signal pair is distributed to clock receiver circuits, which may be differential amplifiers. The clock receiver circuits receive the differential sinusoidal signal pair and convert the differential sinusoidal pair to local clock signals. Power consumption and noise generation are reduced as compared to conventional clock signal distribution arrangements.
摘要:
A method for optimizing the design of a chip or system by decreasing the cost function that encompasses a plurality of constraints in the presence of variations in the design parameters is described. The method makes use of numerical optimization, simulated annealing, or any other objective-driven optimization means, and accounts for uncertainties in the modeling of the design variables and functions. A significant reduction in the number of design constraints which are violated at the end of an optimization process is achieved, even when all the design constraints cannot be satisfied. The optimization also reduces the cycle time at which the design operates and limits the increase in the minimum operational cycle time of a particular implementation in the presence of variations that cannot be modeled or unpredictable variations in delay introduced by elements of the design. The method for optimizing the design includes the steps of: defining an objective function computed from variables and functions of the design of the chip or system; deriving a merit function from the objective function by adding to it a plurality of separation terms; and minimizing the merit function which reduces the expected value of the objective function when confronted with significant variations of the design variables and functions.
摘要:
Both logical and physical construction of voltage islands is disclosed. A semiconductor chip design is partitioned into “bins”, which are areas of the design. In this way, a semiconductor chip design may be “sliced” into various areas and the areas may then be assigned to various voltage levels. Each bin may be thought of as a voltage island. Circuits in the design can be added to or removed from the various bins, thereby increasing or decreasing the speed and power of the circuits: the speed and power increase if a circuit is placed into a bin assigned a higher voltage, and the speed and power decrease if a circuit is placed into a bin having a lower voltage. The size and location of the bins may also be changed. By iterating these steps, the optimum power consumption may be met while still meeting speed constraints and other criteria. The present invention is applicable to any placement environment, such as an annealing placement tool, that proceeds through successive refinement of the locations of the circuits on the design and in which the placement process may be interrupted to make changes in placement of the logic.