Abstract: Distribution of a reset signal across a system-on-chip (SoC) may be the highest latency signal in the circuit. As a result, the operating frequency of the device is reduced to ensure that the reset signal reaches all intellectual property (IP) blocks during a single clock cycle. A reset synchronizer receives the clock signal and the reset signal as inputs and generates a synchronous reset signal as an output. The synchronous reset signal has a fixed timing relationship with the clock signal. The clock signal may be paused when a reset signal is received. As a result, distribution of the synchronous reset signal may be performed without regard to the latency of the signal. After the synchronous reset signal has been received by all of the IP blocks, reset is deasserted and the clock signal is resumed.

Abstract: A four-input lookup table (“LUT4”) is modified to operate in a first mode as an ordinary LUT4 and in a second mode as a 1-bit adder providing a sum output and a carry output. A six-input lookup table (“LUT6”) is modified to operate in a first mode as an ordinary LUT6 with a single output and in a second mode as a 2-bit adder providing a sum output and a carry output. Both possible results for the two different possible carry inputs can be determined and selected between when the carry input is available, implementing a 2-bit carry-select adder when in the second mode and retaining the ability to operate as an ordinary LUT6 in the first mode. Using the novel LUT6 design in a circuit chip fabric allows a 2-bit adder slice to be built that efficiently makes use of the LUT6 without requiring additional logic blocks.

Abstract: A receiving device uses an elastic buffer that is wider than the number of data elements transferred in each cycle. To compensate for frequency differences between the transmitter and the receiver, the transmitting device periodically sends a skip request with a default number of skip data elements. If the elastic buffer is filling, the receiving device ignores one or more of the skip data elements. If the elastic buffer is emptying, the receiving device adds one or more skip data elements to the skip request. To maintain the ordering of data despite the manipulation of the skip data elements, two rows of the wide elastic buffer are read at a time. This allows construction of a one-row result from any combination of the data elements of the two rows. The column pointers are adjusted appropriately, to ensure that they continue to point to the next data to be read.

Abstract: A conflict-free parallel radix sorting algorithm, and devices and systems implementing this algorithm, schedules memory copies of data elements of a large dataset so that there is always a single copy to each target memory each cycle of operation for the system implementing the algorithm. The conflict-free parallel radix sorting algorithm eliminates memory copying conflicts in copying data elements from different source memories to the same target memory and in this way maintains maximum throughput for the copying of data elements from source memories to target memories, reducing the time required to sort the data elements of the large dataset.

Abstract: Multiple designs for a multi-layer circuit may be simulated to determine impedance profiles of each design, allowing a circuit designer to select a design based on the impedance profiles. One feature that can be modified is the structure surrounding the barrels of a differential VIA on layers that are not connected to the differential VIA. Specifically, one antipad can be used that surrounds both barrels or two antipads can be used, with one antipad for each barrel. Additionally, the size of the antipad or antipads can be modified. These modifications affect the impedance of the differential VIA. Additionally, a conductive region may be placed that connects to the VIA barrel even though the circuit on the layer does not connect to the VIA. This unused pad, surrounded by a non-conductive region, also affects the impedance of the differential VIA.

Abstract: Methods, systems, and computer programs are presented for processing Ethernet packets at a Field Programmable Gate Array (FPGA). One programmable integrated circuit includes: an internal network on chip (iNOC) comprising rows and columns; clusters, coupled to the iNOC, comprising a network access point (NAP) and programmable logic; and an Ethernet controller coupled to the iNOC. When the controller operates in packet mode, each complete inbound Ethernet packet is sent from the controller to one of the NAPs via the iNOC, where two or more NAPs are configurable to receive the complete inbound Ethernet packets from the controller. The controller is configurable to operate in quad segment interface (QSI) mode where each complete inbound Ethernet packet is broken into segments, which are sent from the controller to different NAPs via the iNOC, where two or more NAPs are configurable to receive the complete inbound Ethernet packets from the controller.

Abstract: A tile of an FPGA provides memory, arithmetic functions, or both. Connections directly between multiple instances of the tile are available, allowing multiple tiles to be treated as larger memories or arithmetic circuits. By using these connections, referred to as cascade inputs and outputs, the input and output bandwidth of the arithmetic and memory circuits are increased, operand sizes are increased, or both. By using the cascade connections, multiple tiles can be used together as a single, larger tile. Thus, implementations that need memories of different sizes, arithmetic functions operating on different sized operands, or both, can use the same FPGA without additional programming or waste. Using cascade communications, more tiles are used when a large memory is needed and fewer tiles are used when a small memory is needed and the waste is avoided.

Abstract: A logic block can be relocated without recompilation from a first area to a second area on a field-programmable gate array (FPGA) if the pattern of fabric tiles in the second area is the same as the pattern of fabric tiles in the first area, and if the two areas have the same dimensions. The design system runs synthesis, placement, and routing on a partition of a design at a first location, exports that partition to a persistent on-disk database, imports one or multiple copies of the partition into a larger design, and moves one or more of the copies from the first area to a target area in the larger design. The compatibility of the second area may be identified based on fabric tile signatures of the first area and the second area.

Abstract: A tile of an FPGA fuses memory and arithmetic circuits. Connections directly between multiple instances of the tile are also available, allowing multiple tiles to be treated as larger memories or arithmetic circuits. By using these connections, referred to as cascade inputs and outputs, the input and output bandwidth of the arithmetic circuit is further increased. The arithmetic unit accesses inputs from a combination of: the switch fabric, the memory circuit, a second memory circuit of the tile, and a cascade input. In some example embodiments, the routing of the connections on the tile is based on post-fabrication configuration. In one configuration, all connections are used by the memory circuit, allowing for higher bandwidth in writing or reading the memory. In another configuration, all connections are used by the arithmetic circuit.

Abstract: A tile of an FPGA includes a multiple mode arithmetic circuit. The multiple mode arithmetic circuit is configured by control signals to operate in an integer mode, a floating-point mode, or both. In some example embodiments, multiple integer modes (e.g., unsigned, two's complement, and sign-magnitude) are selectable, multiple floating-point modes (e.g., 16-bit mantissa and 8-bit sign, 8-bit mantissa and 6-bit sign, and 6-bit mantissa and 6-bit sign) are supported, or any suitable combination thereof. The tile may also fuse a memory circuit with the arithmetic circuits. Connections directly between multiple instances of the tile are also available, allowing multiple tiles to be treated as larger memories or arithmetic circuits. By using these connections, referred to as cascade inputs and outputs, the input and output bandwidth of the arithmetic circuit is further increased.

Abstract: A four-input lookup table (“LUT4”) is modified to operate in a first mode as an ordinary LUT4 and in a second mode as a 1-bit adder providing a sum output and a carry output. A six-input lookup table (“LUT6”) is modified to operate in a first mode as an ordinary LUT6 with a single output and in a second mode as a 2-bit adder providing a sum output and a carry output. Both possible results for the two different possible carry inputs can be determined and selected between when the carry input is available, implementing a 2-bit carry-select adder when in the second mode and retaining the ability to operate as an ordinary LUT6 in the first mode. Using the novel LUT6 design in a circuit chip fabric allows a 2-bit adder slice to be built that efficiently makes use of the LUT6 without requiring additional logic blocks.

Abstract: A logic block can be relocated without recompilation from a first area to a second area on a field-programmable gate array (FPGA) if the pattern of fabric tiles in the second area is the same as the pattern of fabric tiles in the first area, and if the two areas have the same dimensions. The design system runs synthesis, placement, and routing on a partition of a design at a first location, exports that partition to a persistent on-disk database, imports one or multiple copies of the partition into a larger design, and moves one or more of the copies from the first area to a target area in the larger design. The compatibility of the second area may be identified based on fabric tile signatures of the first area and the second area.

Abstract: A tile of an FPGA provides memory, arithmetic functions, or both. Connections directly between multiple instances of the tile are available, allowing multiple tiles to be treated as larger memories or arithmetic circuits. By using these connections, referred to as cascade inputs and outputs, the input and output bandwidth of the arithmetic and memory circuits are increased, operand sizes are increased, or both. By using the cascade connections, multiple tiles can be used together as a single, larger tile. Thus, implementations that need memories of different sizes, arithmetic functions operating on different sized operands, or both, can use the same FPGA without additional programming or waste. Using cascade communications, more tiles are used when a large memory is needed and fewer tiles are used when a small memory is needed and the waste is avoided.

Abstract: A four-input lookup table (“LUT4”) is modified to operate in a first mode as an ordinary LUT4 and in a second mode as a 1-bit adder providing a sum output and a carry output. A six-input lookup table (“LUT6”) is modified to operate in a first mode as an ordinary LUT6 with a single output and in a second mode as a 2-bit adder providing a sum output and a carry output. Both possible results for the two different possible carry inputs can be determined and selected between when the carry input is available, implementing a 2-bit carry-select adder when in the second mode and retaining the ability to operate as an ordinary LUT6 in the first mode. Using the novel LUT6 design in a circuit chip fabric allows a 2-bit adder slice to be built that efficiently makes use of the LUT6 without requiring additional logic blocks.

Abstract: A receiving device uses an elastic buffer that is wider than the number of data elements transferred in each cycle. To compensate for frequency differences between the transmitter and the receiver, the transmitting device periodically sends a skip request with a default number of skip data elements. If the elastic buffer is filling, the receiving device ignores one or more of the skip data elements. If the elastic buffer is emptying, the receiving device adds one or more skip data elements to the skip request. To maintain the ordering of data despite the manipulation of the skip data elements, two rows of the wide elastic buffer are read at a time. This allows construction of a one-row result from any combination of the data elements of the two rows. The column pointers are adjusted appropriately, to ensure that they continue to point to the next data to be read.

Abstract: Distribution of a reset signal across a system-on-chip (SoC) may be the highest latency signal in the circuit. As a result, the operating frequency of the device is reduced to ensure that the reset signal reaches all intellectual property (IP) blocks during a single clock cycle. A reset synchronizer receives the clock signal and the reset signal as inputs and generates a synchronous reset signal as an output. The synchronous reset signal has a fixed timing relationship with the clock signal. The clock signal may be paused when a reset signal is received. As a result, distribution of the synchronous reset signal may be performed without regard to the latency of the signal. After the synchronous reset signal has been received by all of the IP blocks, reset is deasserted and the clock signal is resumed.

Abstract: A tile of an FPGA includes a multiple mode arithmetic circuit. The multiple mode arithmetic circuit is configured by control signals to operate in an integer mode, a floating-point mode, or both. In some example embodiments, multiple integer modes (e.g., unsigned, two's complement, and sign-magnitude) are selectable, multiple floating-point modes (e.g., 16-bit mantissa and 8-bit sign, 8-bit mantissa and 6-bit sign, and 6-bit mantissa and 6-bit sign) are supported, or any suitable combination thereof. The tile may also fuse a memory circuit with the arithmetic circuits. Connections directly between multiple instances of the tile are also available, allowing multiple tiles to be treated as larger memories or arithmetic circuits. By using these connections, referred to as cascade inputs and outputs, the input and output bandwidth of the arithmetic circuit is further increased.

Abstract: Methods, systems, and computer programs are presented for processing Ethernet packets at a Field Programmable Gate Array (FPGA). One programmable integrated circuit includes: an internal network on chip (iNOC) comprising rows and columns; clusters, coupled to the iNOC, comprising a network access point (NAP) and programmable logic; and an Ethernet controller coupled to the iNOC. When the controller operates in packet mode, each complete inbound Ethernet packet is sent from the controller to one of the NAPs via the iNOC, where two or more NAPs are configurable to receive the complete inbound Ethernet packets from the controller. The controller is configurable to operate in quad segment interface (QSI) mode where each complete inbound Ethernet packet is broken into segments, which are sent from the controller to different NAPs via the iNOC, where two or more NAPs are configurable to receive the complete inbound Ethernet packets from the controller.

Abstract: An S-parameter of a reference impedance is determined and converted to a desired mode of operation. Example modes of operation include a single-ended input output mode, a differential input output mode, and a common input output mode. The complex values of the impedance at each port as a function of frequency can be computed using the novel closed-form quadratic S-parameter equation which utilizes the concept of matched networks by setting the reflections and re-reflections to zero through S-parameter renormalization. Using the S-parameter renormalization, the insertion loss corresponding to zero reflections and re-reflections is calculated. Based on the determination of the matching impedance used to reduce the reflections and re-reflections to zero, a parameter of a circuit comprising the network may be modified to reduce noise.

Abstract: Methods, systems, and computer programs are presented for processing Ethernet packets at a Field Programmable Gate Array (FPGA). One programmable integrated circuit includes: an internal network on chip (iNOC) comprising rows and columns, clusters, coupled to the iNOC, comprising a network access point (NAP) and programmable logic; and an Ethernet controller coupled to the iNOC. When the controller operates in packet mode, each complete inbound Ethernet packet is sent from the controller to one of the NAPs via the iNOC, where two or more NAPs are configurable to receive the complete inbound Ethernet packets from the controller. The controller is configurable to operate in quad segment interface (QSI) mode where each complete inbound Ethernet packet is broken into segments, which are sent from the controller to different NAPs via the iNOC, where two or more NAPs are configurable to receive the complete inbound Ethernet packets from the controller.