Abstract: An electronic automation system performs register retiming on a logic design, which may be a logic design for a programmable logic integrated circuit. Register retiming is a moving or rearranging of registers across combinatorial logic in a design in order to improve a maximum operating frequency or fmax. In one implementation, the system includes machine-readable code, which may be stored on a computer-readable medium such as a disk, executing on a computer. The system balances timing in order to trade off delays between critical and noncritical paths. Register retiming may make changes to a design at a gate level.

Abstract: A method for designing a system on a target device is described. In one embodiment of the method, a plurality of registers is replaced with at least one register and a timing exception. In one embodiment, the registers in the plurality of registers are in series or substantially in series. In one embodiment, the timing exception is a multi-cycle exception. In one embodiment, the method also includes identifying a critical combinational logic path that is followed or preceded by the plurality of registers. Further, in one aspect, the timing exception is removed and registers are inserted into the critical combinational logic path to account for the removed timing exception. In one embodiment, a network flow algorithm is performed to determine the locations for inserting registers.

Abstract: A field programmable gate array (“FPGA”) is provided having integrated application specific integrated circuit (“ASIC”) fabric. The ASIC fabric may be used to implement one or more custom or semi-custom hard blocks within the FPGA. The ASIC fabric can be made up of a “custom region” and an “interface region.” The custom region can implement the custom or semi-custom ASIC design and the interface region can integrate and connect the custom region to the rest of the FPGA circuitry. The custom region may be based on a structured ASIC design. The interface region may allow the ASIC fabric to be incorporated within the hierarchical organization of the FPGA, allowing the custom region to connect to the FPGA circuitry in a seamless manner.

Abstract: A field programmable gate array (“FPGA”) is provided having integrated application specific integrated circuit (“ASIC”) fabric. The ASIC fabric may be used to implement one or more custom or semi-custom hard blocks within the FPGA. The ASIC fabric can be made up of a “custom region” and an “interface region.” The custom region can implement the custom or semi-custom ASIC design and the interface region can integrate and connect the custom region to the rest of the FPGA circuitry. The custom region may be based on a structured ASIC design. The interface region may allow the ASIC fabric to be incorporated within the hierarchical organization of the FPGA, allowing the custom region to connect to the FPGA circuitry in a seamless manner.

Abstract: A method for designing a system on a target device is disclosed. Domains and sub-domains in the system are identified. A sub-domain is divided into a plurality of chunks. Slacks for the chunks are computed in parallel. Other embodiments are described and claimed.

Abstract: Circuits, methods, software, and apparatus that track the removal of, reasons for, and consequence of the removal of registers or other circuitry during the synthesis of electronic circuits. An exemplary embodiment of the present invention tracks the removal of registers and determines why the registers were removed. This information is then provided in an efficient manner for design debugging purposes.

Abstract: A performance estimation module estimates the performance values of user designs in early phases of compilation and accounts for the performance variability introduced by subsequent compilation phases. The user design is parameterized. The performance estimation model outputs a probability distribution function of estimated performance values of the user design, based upon this parameterization. The performance estimation model is created by parameterizing sample designs. The sample designs are compiled and analyzed to determine their performance values. To account for random variability in compilation phases, the module compiles and analyzes sample designs multiple times. The performance estimation model is created from the relationship between sample designs' performance values and their parameterizations. A regression analysis may be used to determine this relationship. The performance estimation model can be updated with the analysis of compiled user designs.

Abstract: An electronic automation system performs register retiming on a logic design, which may be a logic design for a programmable logic integrated circuit. Register retiming is a moving or rearranging of registers across combinatorial logic in a design in order to improve a maximum operating frequency or fmax. In one implementation, the system includes machine-readable code, which may be stored on a computer-readable medium such as a disk, executing on a computer. The system balances timing in order to trade off delays between critical and noncritical paths. Register retiming may make changes to a design at a gate level.

Abstract: A high efficiency PLD architecture having logic elements that can be selectively combined to perform higher order logic functions than can be performed alone by a single logic element. The programmable logic device includes a logic block having a first logic element. The first logic element includes a first pair of sub-function generators and is capable of implementing logic functions of a first order. The logic block also includes a second logic element having a second pair of sub-function generators. A programmable sharing circuitry is also included in the logic block. The programmable sharing circuitry selectively couples the first pair of sub-function generators and the second pair of sub-function generators so that the first logic element is capable of performing logic functions of either (i) the first order, or (ii) a second order. The second order is higher than the first order.

Abstract: The tension between fmax and Tco in a specialized processing block of a programmable integrated circuit device can be reduced by providing variable delays on the clock inputs of the pipeline registers within the specialized processing block. This allows the introduction of beneficial skew that allows slower functions to be performed within the specialized processing block rather than outside the block, thereby reducing Tco, without slowing down the clock—i.e., without reducing fmax. This technique may also apply to other specialized blocks such as memory.

Abstract: A pragma is used to pass circuit type information to a Computer Aided design (CAD) tool. The CAD tool then selects an alternate synthesis or timing algorithm based on the circuit type, and a circuit design for use in an electronic device is created. Practical applications include using alternate algorithms specific to different circuit types, such as, Cyclic Redundancy Checks (CRC), bus arbiters, state machine encoders, barrel shifters, preferential cores, and legacy circuits. One embodiment generates informative messages for the designer once the circuit type is known and the analysis is performed. Another embodiment generates pragmas that can be later used by circuit designers in future circuit designs.

Abstract: Disclosed is a programmable logic device (“PLD”) including at least one lookup table (“LUT”) based logic element (“LE”) of a first type and at least one LUT based LE of a second type. The first type of LE is different from the second type of LE. The term ‘different’ when used herein to describe the relationship of a first logic structure and/or its components to a second logic structure and/or its components indicates a difference in hardware design as opposed to a configuration difference or non-designed differences resulting, for example, from manufacturing variability. Additionally, a PLD can include at least one logic array block (“LAB”) of a first type having at least one LUT based LE and at least one LAB of a second type having at least one LUT based LE. The first type of LAB being different from the second type of LAB.

Abstract: A programmable logic device architecture having logic elements with dedicated hardware to configure the look up tables of the logic element to either perform logic functions or to operate as a register for pipelining or other purposes. The programmable logic device includes a general interconnect and a plurality of logic array blocks interconnected by the general interconnect. Each of the plurality of logic blocks further includes one or more logic elements. The logic elements each include a first look up table, a second look up table, and dedicated hardware within the logic element to configure the first look table and the second look up table as a register without having to use the general interconnect. In one embodiment, the dedicated hardware includes a plurality of dedicated interconnects within the logic element to configure the two look up tables as a pair of cross coupled muxes or latches when configured as a register.

Abstract: A programmable logic device (PLD) includes a configuration circuit, and first and second freeze-logic circuits. The configuration circuit provides configuration data for configuring programmable resources of the PLD during a configuration mode of the PLD. One of the two freeze-logic circuits provides a freeze logic signal during the configuration mode of the PLD. The other freeze-logic circuit provides a freeze logic signal during a user mode of the PLD.

Abstract: Serializing circuitry is provided that can multiplex multiple device output signals and that can drive time-multiplexed data signals on the bus wires of a data path of an electronic system. Bus registers placed at the ends of the bus wires can register or buffer the data signals transmitted over the bus wires. The registered signals may be passed on to deserializing circuitry for demultiplexing the data signals to provide parallel device input signals. The bus registers and the serializing/deserializing circuitry can be provided along signal paths that require additional latency.

Abstract: A skew generator unit includes a delay chain. The delay chain is coupled to a clock line that transmits a clock signal. The delay chain generates a skewed clock signal having a unit of delay from the clock signal. The skew generator unit also includes a selector. The selector is coupled to the delay chain and the clock line and may select one of the clock signal and the skewed clock signal.

Abstract: A high efficiency PLD architecture having adjacent logic elements that can be selectively combined to perform higher order logic functions than can be performed alone by a single logic element. The programmable logic device includes a logic block having a first logic element including a first look up table. The first look up table includes a first pair of sub-function generators and is capable of implementing logic functions of a first order. The logic block also includes a second logic element having a second input look up table including a second pair of sub-function generators. Programmable sharing circuitry is also included in the logic block. The programmable sharing circuitry selectively couples the first pair of sub-function generators and the second pair of sub-function generators so that the first logic element is capable of performing logic functions of either (i) the first order, or (ii) a second order, wherein the second order is higher than the first order.

Abstract: To improve interfacing between a block of dedicated function circuitry and blocks of more general purpose circuitry on an integrated circuit (“IC”), signals that are to be output by the dedicated function block are routed internally in that block so that they go into interconnection circuitry on the IC for more efficient application by that interconnection circuitry to the general purpose circuitry. Some of this routing internal to the dedicated function block may be controllably variable. The routing internal to the dedicated function block may also be arranged to take advantage of “sneak” connections that may exist between the dedicated function block and the general purpose blocks.

Abstract: A visualization displays user designs and performance information at different levels of detail. Related register bits are combined into a metaregister and displayed as a graph node. The set of paths and associated combinatorial logic between two or more metaregisters are collapsed into a metapath and displayed as a graph connection. The set of paths associated with a metapath can be selectively revealed in response to user input. Metapaths can be annotated with performance information of its associated paths, such as timing, area, and power consumption information. The annotated performance information can represent performance information of one or more paths or aggregate attributes of the set of paths. Paths associated with control signals and finite state machines can be identified and displayed as separate graph connections.

Abstract: A field programmable gate array (“FPGA”) is provided having integrated application specific integrated circuit (“ASIC”) fabric. The ASIC fabric may be used to implement one or more custom or semi-custom hard blocks within the FPGA. The ASIC fabric can be made up of a “custom region” and an “interface region.” The custom region can implement the custom or semi-custom ASIC design and the interface region can integrate and connect the custom region to the rest of the FPGA circuitry. The custom region may be based on a structured ASIC design. The interface region may allow the ASIC fabric to be incorporated within the hierarchical organization of the FPGA, allowing the custom region to connect to the FPGA circuitry in a seamless manner.