Abstract: A message unit for transmitting messages in a data processing system characterized by an execution cycle is described. The message unit includes a message array and message transfer circuitry. The message transfer circuitry is operable to facilitate transfer of a message stored in a first portion of the message array in response to a first message transfer request. The message transfer circuitry is further operable to store up to one additional message transfer request per execution cycle while facilitating transfer of the message, and to maintain strict ordering between overlapping requests.

Abstract: Methods and apparatus are described for facilitating physical synthesis of a circuit design. The circuit design includes a plurality cell instances organized hierarchically. Each cell instance corresponds schematically to one of a plurality of cell types. Transistors in each of the cell instances is sized with reference to an objective function thereby resulting in a first plurality of cell subtypes for each cell type. Each cell subtype corresponding to a particular cell type differs from all other cell subtypes corresponding to the particular cell type by at least one transistor dimension. Selected ones of the subtypes for at least one of the cell types are merged thereby resulting in a second plurality of subtypes for the at least one of the cell types. The second plurality of subtypes being fewer than the first plurality of subtypes. The merging of the selected subtypes achieves a balance between the objective function and a cost associated with maintaining the selected subtypes distinct.

Abstract: Methods and apparatus are described for facilitating physical synthesis of an integrated circuit design. A set of paths between observable nodes in a netlist representing the circuit design is generated. Each path corresponds to a sequence of signal transitions. Transistors represented in the netlist are sized to attempt to meet a delay constraint for each path. The delay constraint corresponds to a unit delay times the number of signal transitions in the corresponding path. A plurality of individual delays of different durations are allocated among the transitions for at least one of the paths to meet the delay constraint. At least one of the individual delays exceeds the unit delay.

Abstract: An interface for use between an asynchronous domain and a synchronous domain is described. The asynchronous domain is characterized by transmission of data in accordance with a delay-insensitive handshake protocol. The synchronous domain is characterized by transmission of data in accordance with transitions of a clock signal. The interface includes a datapath operable to transfer a data token between the domains. The interface also includes control circuitry operable to enable transfer of the data token via the datapath in response to a transition of the clock signal and at least one completion of the handshake protocol.

Abstract: An interface for use between an asynchronous domain and a synchronous domain is described. The asynchronous domain is characterized by transmission of data in accordance with a delay-insensitive handshake protocol. The synchronous domain is characterized by transmission of data in accordance with transitions of a clock signal. The interface includes a datapath operable to transfer a data token between the domains. The interface also includes control circuitry operable to enable transfer of the data token via the datapath in response to a transition of the clock signal and at least one completion of the handshake protocol.

Abstract: Methods and apparatus are described relating to a crossbar which is operable to route data from any of a first number of input channels to any of a second number of output channels according to routing control information. Each combination of an input channel and an output channel corresponds to one of a plurality of links. The crossbar circuitry is operable to route the data in a deterministic manner on each of the links thereby preserving a partial ordering represented by the routing control information. Events on different links are uncorrelated.

Abstract: Methods and apparatus are described relating to a crossbar which is operable to route data from any of a first number of input channels to any of a second number of output channels according to routing control information. Each combination of an input channel and an output channel corresponds to one of a plurality of links. The crossbar circuitry is operable to route the data in a deterministic manner on each of the links thereby preserving a partial ordering represented by the routing control information. Events on different links are uncorrelated.