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:
In integrated circuit (IC) designs, a component of power consumed may be represented as Power=½ FCV2, where C is the load capacitance being driven by a source cell, F is the switching frequency of the source cell, and V is the total output voltage swing. However, not every signal value generated by a source cell is required to propagate to all the sink cells connected to the source for every clock cycle of a chip. Accordingly, an isolate cell is inserted in a net (wire) connecting a source cell to at least one sink cell, to de-couple the at least one sink cell and a portion of the net from the source cell when a signal output by the source need not propagate. Due to the de-coupling, the load capacitance associated with the at least one sink and net portion is not experienced by the source cell for such signals. Accordingly, overall IC power consumption is reduced.
摘要:
An electrical wiring structure and a computer system for designing the electrical wiring structure. The electrical wiring structure includes a wire pair. The wire pair includes a first wire and a second wire. The second wire is slated for being tri-stated. The wire pair has a same-direction switching probability φSD per clock cycle that is no less than a pre-selected minimum same-direction switching probability φSD,MIN or has an opposite-direction switching probability φOD per clock cycle that is no less than a pre-selected minimum opposite-direction switching probability φOD,MIN. The first wire and the second wire satisfies at least one mathematical relationship involving LCOMMON and WSPACING, where WSPACING is defined as a spacing between the first wire and the second wire, and LCOMMON is defined as a common run length of the first wire and the second wire.
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:
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 method for constructing delay rules which include the effects of MIS simulations for static timing analysis with reduced cost. The present method includes constructing skew windows for applying MIS penalties purely from SIS data, and scales the MIS penalties during rule use based upon how closely the skews in the use case approach the edge of the skew window. The method applies both to timing rule construction for a library of circuits and to timing rule construction for macros where only part of the circuits in the macro may be sensitive to skew between macro inputs.
摘要:
A method for efficient multithreaded analysis of a timing graph is described. The method is applicable to multithreaded common path pessimism removal, critical path traversing for timing report generation, and other types of analysis requiring traversal of sub-graphs of timing graph. In order to achieve high efficiency and scalability for parallel multithreaded execution, the number of access locks is minimized. One parent computation thread and multiple child threads are employed. The parent computational thread identifies the tasks for analysis and distributes them among child threads. Each child thread identifies a sub-graph to be analyzed, creates a thread-specific replica of the identified sub-graph, and performs the analysis required. After completing the analysis, the child thread transfers the results back to the main timing graph and waits for next task. As all data structures of each child thread are accessed only by the child thread owing them, no access locks are required for construction and processing of thread specific graph replica of the timing sub-graph. The construction of each thread specific graph replica is performed by the child thread without locking the main timing graph data structures. Access locks are used only for transferring results of the analysis back to the main timing graph where the results computed by all child threads are combined together.
摘要:
Disclosed are embodiments of a system and of an associated method for estimating the leakage current of an electronic circuit. The embodiments analyze a layout of an electronic circuit in order to identify all driven and non-driven nets within the electronic circuit, to identify all of the driven net-bounded partitions within the electronic circuit (based on the driven and non-driven nets), and to identify, for each driven net-bounded partition, all possible states of the electronic circuit that can leak. Then, using this information, the embodiments estimate the leakage current of the electronic circuit. This is accomplished by first determining, for each state of each driven net-bounded partition, a leakage current of the driven net-bounded partition and a probability that the state will occur in the driven net-bounded partition during operation of the electronic circuit. Then, for each state of each driven net-bounded partition, the leakage current of the driven net-bounded partition and the state probability are multiplied together. The results are then aggregated.
摘要:
A method for loading checkpoint timing in an environment where the boundary arrival times, slews, required arrival times, or loads differ from the checkpoint run. A timing checkpoint file generated for one or more hierarchical modules, during which each input is assigned a unique phase tag. The association of unique phase tags allows subsequent restart analyses to efficiently adjust the checkpoint timing in relation to the restart timing environment. In the restart run, one or more such checkpoint files is read, during which an initial propagation of arrival, required arrivals and slew times are performed, followed by a local re-update based on adjusted arrival times and the required arrival times. Finally, if multiple hierarchical modules are updated, a global recalculation of timing values is performed based on a slack change threshold in order to determine whether any new timing failures have been introduced.