摘要:
Methods and apparatuses to automatically modify a circuit design (e.g., a synthesis solution) according to the sensitivity in design parameters with respect to the possible deviation in the subsequent implementation (e.g., placement and routing) of the circuit. In one aspect of the present invention, a method to design a circuit includes: determining likelihood of a design constraint being violated in an implementation of a first circuit design (e.g., a technology specific netlist with or without a placement solution); and, modifying the first circuit design to reduce the likelihood of the design constraint being violated. In one example, the implementation of the first circuit design includes a routing solution for implementing the first circuit design; and, the first circuit is modified through sizing an instance of a logic element, buffering a signal, load shielding for a signal, or other operations.
摘要:
Methods and apparatuses to multiplex logic data pseudo synchronously are described. A representation of a multiplexer logic is generated to transmit data items asynchronously relative to a design clock. The data items may be transmitted under control of a transmission clock from a first integrated circuit to a second integrated circuit. A representation of a counter logic may be generated to couple with the multiplexer logic for transmitting the data asynchronously. Additionally, a representation of reset logic may be generated for a configuration to repeatedly reset the counter logic. Synchronization signals may be generated for a design clock cycle of a design clock driving the data items. The synchronization signals may be transmitted via the transmission clock asynchronous with the design clock. The data items may be transmitted via a number of transmission slots determined based on the clock cycles of the transmission clock and the design clock The total time for the transmission slots for transmitting the logic data may be less than the clock cycle of the design clock. One or more transmission slots within the clock cycle of the design clock may be used to transmit the synchronization data to indicate a new cycle to transmit the data items according to the design clock.
摘要:
In one aspect of an embodiment, a method implemented on a data processing system for circuit design, includes identifying one or more first portions of a design of a circuit, each of the one or more first portions containing a set of elements interconnected via timing nets and generating weights for the timing critical nets, the weights being generated after identifying the one or more first portions and executing a placer algorithm which uses the weights for the timing critical nets to place the set of elements on a representation of the design. In this method, in one embodiment, the weights for the timing critical nets can be generated to have values that differ from weights for non-critical nets. The placer algorithm can be any one of a variety of conventional placer algorithms such as a weighted wire length driven placer algorithm or a force directed timing driven placer algorithm or a min-cut placer algorithm.
摘要:
In one aspect of an embodiment, a method implemented on a data processing system for circuit design, includes: identifying one or more first portions (e.g., islands) of a design of a circuit, where each of the one or more first portions contains a set of elements interconnected via timing critical nets; and reporting inter-dependency between portions of the circuit in view of the one or more first portions. In one aspect of an embodiment, a method implemented on a data processing system for circuit design, includes: identifying a first portion (e.g., island) of a design of a circuit, the first portion containing a set of elements interconnected via timing critical nets; and performing a synthesis transformation of the first portion to isolate timing dependency of the first portion on a non-critical net connected to an element of the first portion.
摘要:
Methods and apparatuses to design an Integrated Circuit (IC) with a shielding of wires. In at least one embodiment, a shielding mesh of at least two reference voltages (e.g., power and ground) is used to reduce both the capacitive coupling and the inductive coupling in routed signal wires in IC chips. In some embodiments, a type of shielding mesh (e.g., a shielding mesh with a window surrounded by a power ring, or a window with a parser set of shielding wires) is selected to make more routing area available in locally congested areas. In other embodiments, the shielding mesh is used to create or add bypass capacitance. Other embodiments are also disclosed.
摘要:
Methods and apparatuses to automatically generate time multiplexed multi-channel circuits from single-channel circuits. At least one embodiment of the present invention automatically and efficiently synthesize multi-channel hardware for time-multiplexed resource sharing by automatically generating a time multiplexed design of multi-channel circuits from the design of a single-channel circuit. Channel specific elements of the single-channel design (e.g., registers and memories) are replaced with corresponding elements of N-times more capacity for pipelining the signal processing for multiple channels.
摘要:
Techniques for timing-optimal placement, pin assignment, and routing for integrated circuits are described herein. According to one embodiment, a list of paths providing implementation possibilities is constructed. A means is provided for removing paths from the list as well as a means for committing paths to the implementation if such paths are required for making the circuit implementation valid. Paths with worst case attributes are iteratively removed from the list until all paths in the list are committed to the implementation. Other methods and apparatuses are also described.
摘要:
Methods and apparatuses to design an Integrated Circuit (IC) with a shielding of wires. In at least one embodiment, a shielding mesh of at least two reference voltages (e.g., power and ground) is used to reduce both the capacitive coupling and the inductive coupling in routed signal wires in IC chips. In some embodiments, a type of shielding mesh (e.g., a shielding mesh with a window surrounded by a power ring, or a window with a parser set of shielding wires) is selected to make more routing area available in locally congested areas. In other embodiments, the shielding mesh is used to create or add bypass capacitance. Other embodiments are also disclosed.
摘要:
Methods and apparatuses to automatically determine conditions at hierarchical boundaries of a hierarchical circuit design and to use the determined conditions in hierarchical optimization and verification. In one embodiment, a hierarchical block is optimized and transformed during design synthesis using one or more lemmas at the boundary of the hierarchical block. For example, the lemmas are automatically generated to specify range information for input boundary nodes. The lemmas are also used for the equivalence checker to perform hierarchical equivalence checking. Equivalence of hierarchical blocks is individually checked, in view of the lemmas. Thus, based on the lemmas, optimizations across hierarchical boundaries can be performed, while the hierarchical structure of the design is preserved so that equivalence checking of hierarchical circuit designs can still be based on the equivalence of individual hierarchical blocks.
摘要:
Methods and apparatuses for circuit design to reduce power usage, such as reducing temperature dependent power usage, and/or to improve timing, such as reducing temperature dependent delay or transition time. At least one embodiment of the present invention reduces the power dissipation and improves the timing of an integrated circuit to optimize the design. A thermal analysis is used to determine the temperature dependent power dissipation of a circuit and the temperature distribution of the circuit resulting from dissipating the heat created by the temperature dependent power dissipation. Then, the components of the design are selectively transformed to reduce the power dissipation and to improve timing based on the temperature solution. The transformation may include placement changes and netlist changes, such as the change of transistor threshold voltages for cells or for blocks of the circuit chip.