Abstract: In one embodiment, a clock distribution chip includes a clock input adapted to receive an input clock signal, clock dividers each adapted to receive a clock signal based on the first input clock signal and to generate a divided clock signal, and programmable clock outputs adapted to provide output clock signals. The clock outputs are configurable to support a number of signaling standards. A programmable switch fabric is coupled between the clock dividers and the clock outputs and is configurable to provide the divided clock signals to the clock outputs.

Abstract: In one embodiment, a clock distribution chip includes a first clock input adapted to receive a first single-ended input clock signal, a second clock input adapted to receive a second single-ended input clock signal, and input buffer circuitry coupled to the first and second clock inputs. The input buffer circuitry is adapted to select an input clock signal among the first single-ended input clock signal, the second single-ended input clock signal, and a differential input clock signal derived from the first and second single-ended input clock signals. A phase-locked loop (PLL) is adapted to receive an input clock signal selected by the input buffer circuitry and to generate a PLL clock signal based on the selected input clock signal. A clock output provides an output clock signal based on the PLL clock signal.

Abstract: In one embodiment of the invention, a clock distribution (CD) chip has one or more input pins, input buffer circuitry, clock generation and distribution circuitry, fanout circuitry, one or more output pins, a feedback pin, and feedback buffer circuitry. Based on single-ended or differential input clock signals applied to the input pins, the CD chip can be programmably configured to generate zero, one, or more zero-delay (ZD) output clock signals and zero, one, or more non-zero-delay (NZD) output clock signals for simultaneous presentation at the output pins.

Abstract: A programmable logic block within a programmable logic device includes at least two interconnected slices, each of the interconnect slices including at least two interconnected lookup tables. Each interconnected lookup table is adapted to receive input signals from a routing structure and to provide a LUT output signal. At least one of the slices includes a register adapted to register the LUT output signal of a lookup table and at least another of the slices includes fewer such registers than lookup tables.

Abstract: In one embodiment of the invention, a programmable logic block within a programmable logic device includes: a plurality of lookup tables, each lookup table providing a combinatorial output signal; and a plurality of registers, each register being adapted to register a selected one of the combinatorial output signals, wherein the number of registers is less than the number of lookup tables.

Abstract: Programmable logic devices and techniques for programming and/or reconfiguring these devices are disclosed. For example, in accordance with an embodiment of the present invention, a programmable logic device is disclosed that incorporates flash memory and SRAM and includes multiple data ports for programming the flash memory and/or the SRAM.

Abstract: Programmable devices, such as FPGAs, are designed with I/O buffer architectures having (at least) three different types of I/O buffers: single-ended buffers with Peripheral Component Interconnect (PCI) clamps, single-ended buffers without PCI clamps, and differential buffers without PCI clamps. By distributing these different types of I/O buffers around the periphery of the device, a relatively low-cost device can be implemented with relatively small I/O buffers that collectively provide all of the I/O signaling functionality of prior-art devices that are implemented with relatively large, all-purpose I/O buffers, each of which supports the full range of I/O signaling options available on the device.

Abstract: Programmable logic devices and techniques for programming and/or reconfiguring these devices are disclosed. For example, in accordance with an embodiment of the present invention, a programmable logic device is disclosed that incorporates flash memory and SRAM and includes multiple data ports for programming the flash memory and/or the SRAM.

Abstract: Systems and methods are disclosed to provide clock generation. In accordance with one embodiment, a clock generator chip is provided that is configurable and in-system programmable. The clock generator chip may provide programmable input circuits, programmable output circuits, and permit a JTAG boundary scan.

Abstract: Systems and methods are disclosed to provide clock generation. In accordance with one embodiment, a clock generator chip is provided that is configurable and in-system programmable and includes a flexible skew control architecture. The clock generator chip may also provide programmable input circuits, programmable output circuits, and permit a JTAG boundary scan.

Abstract: A programmable logic device is disclosed having a delay line macrocell with programmably selectable taps feeding inputs to a programmable logic circuit. The delay line taps may feed the programmable logic circuit through logic circuit driving circuitry, which performs a certain amount of prepossessing on the tap signals before being provided to the programmable logic circuit. Outputs of the programmable logic circuit, which may be a programmable AND array followed by a fixed OR array, are provided to the edge-triggered inputs of dual set/reset flip flops. Other outputs of the programmable logic circuit are selectable as inputs to the delay line.

Abstract: Method and apparatus providing a programmable logic device which has a high level subroutine stack element and a random access memory suitable for control applications. The method utilizes high level constructs bearing a one-to-one relationship to the architecture of the apparatus so that the design of the controller is facilitated resulting in a rapidly-executed program which is easy to comprehend, verify and document. Subroutines are readily implemented by the controller by virtue of its last-in, first-out stack and a state counter which allow the contents of the counter to be "pushed" onto the stack upon invocation of the subroutine and "popped" from the stack upon return from the subroutine. Provision of the random access memory allows the controller to store information supplied from an external device, such as a central processing unit. The operation of the controller can be readily modified according to the control information stored in the memory by use of a high level language RAMREAD construct.

Abstract: A method for designing a control sequencer having a high level counter element and a programmable AND array suitable for control applications. The method utilizes high level constructs bearing a one-to-one relationship to the architecture of the apparatus so that the design of the controller is facilitated resulting in a rapidly-executed program which is easy to comprehend, verify and document. Moore and Mealy state machines are readily implemented by the controller by virtue of its programmable AND array and counter which allow the next-state and output to be based on the contents of the counter as well as any set of input signals. Conditional testing can be made entirely state dependent, partially-state dependent, or state-independent.

Abstract: Disclosed is an integrated circuit having multiple programmable arrays providing customizable logic. The integrated circuit has at least a first programmable array receiving a plurality of first inputs and generating a plurality of first outputs as programmed by the user. Also, it includes a second programmable array receiving a plurality of second inputs and generating a plurality of second outputs as programmed by the user. A means for selectiving interconnecting the inputs and outputs from the first and second programmable arrays is provided so that the programmable signals generated can be selectively connected in series, in parallel, or in a combination of series and parallel. Also provided are buried state registers for storing signals as programmed by the user. The stored signals from the buried state registers are likewise selectively interconnected with the input signals and output signals to provide added flexibility and power for the logic designer utilizing the device of the present invention.

Abstract: A programmable logic device has a high level counter element and a programmable AND array suitable for control applications. Moore and Mealy state machines are readily implemented by the controller by virtue of its programmable AND array and counter which allow the next-state and output to be based on the contents of the counter as well as any set of input signals. Conditional testing can be made entirely state dependent, partially-state dependent, or state-independent. Multiway branching is also readily implemented since the presence of the programmable AND array allows the user to specify a number of sets of input conditions, so that from a given state, as determined by the counter contents, each set of input condition gives rise to a transition to a specified next state. Instructions can be stored in the AND array in a logical form directly useable by the hardware.

Abstract: A logic circuit communicating to and from an input/output port in a variety of input modes and in a variety of output modes. The circuit may be configured to have a dedicated, registered, or latched input; and in the output mode to have a registered, combinatorial or latched output. A register/latch, in conjunction with a programmable input select multiplexer, can function as an input, output or buried register or as a transparent latch. A programmable clock select multiplexer selects between a clock/latch enable signal applied at an external pin or a product term generated internally. Clock polarity control is also provided. Asynchronous reset and preset of the register/latch is provided along with polarity control therefor. Dedicated and programmable feedback paths are provided. An output inverter can selectably be enabled from internal signals or from an external pin. The logic circuit can be deployed in banks, each bank electably receiving the same or a different clock.

Abstract: An integrated circuit having multiple programmable arrays in which a first programmable array receives a plurality of first inputs and generates a plurality of first outputs as programmed by the user. Also, a second programmable array receives a plurality of second inputs and generates a plurality of second outputs as programmed by the user. Also, buried state registers store signals as programmed by the user. An input multiplexer selects and supplies the first and second inputs from a variety of sources, including the first and second outputs, the buried state registers and I/O pins. An output multiplexer selects and supplies output signals to a set of output pins from a variety of sources, including the first and second outputs and the buried state registers.