Abstract: An in-system programmable and verifiable (ISPAV) configuration restoring device (CROP device) has an Electrically Erasable and reprogrammable, NonVolatile Integrated Storage array (e.g., a FLASH EE.sub.-- NVIS array) into which configuration instructions may be written for later readout during configuration restoration of a Programmable Logic Device (PLD) where the PLD has a volatile configuration memory. The volatile PLD may be an FPGA or a CPLD. The ISPAV CROP device includes a shared shift register through which configuration instructions read from the EE.sub.-- NVIS array are serially shifted out to a to-be-configured PLD. The shared shift register is also used for loading new configuration instructions into the EE.sub.-- NVIS array by way of a 4-wire interface such as JTAG and also for verifying proper writing of these instructions into the EE.sub.-- NVIS array.

Abstract: A Variable Grain Architecture (VGA) includes a shared output component (SOC) that may be used for outputting different signals onto a shared longline within an FPGA. Plural VGB's make shared use of the SOC to out respective function signals to the shared longline.

Abstract: A Variable Grain Architecture is disclosed wherein Variable Grain Blocks (VGB's) are wedged together in mirror opposition to one another to define super-VGB structures. The super-VGB structures are arranged as a matrix within an FPGA device. Each VGB includes progressive function synthesizing layers for forming more complex function signals by folding together less complex function signals of preceding layers. A function spawning layer containing a set of function spawning lookup tables (LUT's) is provided near the periphery of the corresponding super-VGB structure. In one case, the function spawning layer is L-shaped and includes a symmetrical distribution of Configurable Building Blocks. A signal-acquiring layer interfaces with adjacent interconnect lines to acquire input terms for the LUT's and controls. A decoding layer is interposed between the signal-acquiring layer and the function spawning layer for providing strapping and intercept functions.

Abstract: A serial scan chain extends into an array of SRAM cells within a multi-ported memory system for allowing serial introduction of write data into the SRAM cells and serial read-back of the data. Initial data may be pre-loaded into the SRAM cells by way of the serial scan chain before being read parallel-wise in response to read requests submitted through any of multiple, parallel data access ports of the system.

Abstract: A field-programmable gate array device (FPGA) having plural rows and columns of logic function units (VGB's) further includes a plurality of embedded memory blocks, where each memory block is embedded in a corresponding row of logic function units. Each embedded memory block has an address port for capturing received address signals and a controls port for capturing supplied control signals, including a read-mode (RMODE) control signal that switches the memory block between synchronous and asynchronous data transfer modes. Interconnect resources are provided including a Memory Controls-conveying Interconnect Channel (MCIC) for conveying shared address and control signals to plural ones of the memory blocks on a broadcast or narrowcast basis.

Abstract: A Field Programmable Gate Array (FPGA) device includes a plurality of input/output blocks (IOBs) and variable grain blocks (VGBs) An inter-connect network provides routing of signals between the IOBs and VGBs. The VGBs include a plurality of L-organized CBBs (configurable logic blocks) having function-producing resources. The IOBs are arranged along a top, left, bottom and right side of the plurality of VGBs. An IOB includes a 1) delay for timing input signals, 2) a configurable output latch which may be set or reset responsive to control signals, and 3) transistor for controlling a NOR line. The IOB is programmably configured to the inter-connect network which includes vertical and horizontal inter-connect channels comprising adjacent inter-connect lines.

Abstract: A programmable logic device (PLD) cell is used to construct a high density high performance programmable logic device (PLD). The PLD cell includes two programmable logic block cells. The PLD cell also includes an I/O cell and an input macrocell. In addition the PLD cell includes a sub-bank of a programmable output switch matrix bank and a sub-bank of a programmable input switch matrix bank. Each programmable logic block cell includes a multiplicity of product terms. At least one product term in the cluster is programmably available to the cluster. When the product term is disconnected from the cluster, the product term is used for control of the polarity of the logic macrocell output signal or asynchronous functions. Thus, the programmably connectable product term can be used for either synchronous or asynchronous operations. If the programmably connectable and disconnectable product term is connected to the product term cluster, the programmable logic block cell is used for synchronous operations.

Abstract: A Field Programmable Gate Array (FPGA) device includes a plurality of input/output blocks (IOBs) and variable grain blocks (VGBs). An inter-connect network provides routing of signals between the IOBs and VGBs. The VGBs include a plurality of L-organized CBBs (configurable logic blocks) having function-producing resources. The IOBs are arranged along a top, left, bottom and right side of the plurality of VGBs. An IOB includes a 1) delay for timing input signals, 2) a configurable output latch which may be set or reset responsive to control signals, and 3) transistor for controlling a NOR line. The IOB is programmably configured to the inter-connect network which includes vertical and horizontal inter-connect channels comprising adjacent inter-connect lines. The IOB inputs are connected to adjacent inter-connect lines including 1) direct connect input lines from adjacent super-VGBs, 2) MaxL lines, and 3) dendrite lines from adjacent dendrites.

Abstract: A Field Programmable Gate Array (FPGA) device includes a plurality of input/output blocks (IOBs) and variable grain blocks (VGBs). An inter-connect network provides routing of signals between the IOBs and VGBs. The VGBs include a plurality of L-organized CBBs (configurable logic blocks) having function-producing resources. The IOBs are arranged along a top, left, bottom and right side of the plurality of VGBs. An IOB includes a 1) delay for timing input signals, 2) a configurable output latch which may be set or reset responsive to control signals, and 3) transistor for controlling a NOR line. The IOB is programmably configured to the inter-connect network which includes vertical and horizontal inter-connect channels comprising adjacent inter-connect lines. The IOB inputs are connected to adjacent inter-connect lines including 1) direct connect input lines from adjacent super-VGBs, 2) MaxL lines, and 3) dendrite lines from adjacent dendrites.

Abstract: Each programmable logic device in at least two families of high density segmented programmable array logic device utilizes a programmable switch interconnection matrix to couple an array of symmetric programmable logic blocks. Each programmable logic block includes programmable logic macrocells, programmable input/output macrocells, a logic allocator and a programmable product term array. The programmable switch matrix provides centralized global routing with a fixed path independent delay and decouples the logic macrocells from the product term array. The logic allocator decouples the product term array from the logic macrocells, and the I/O macrocells decouple the logic macrocells from the package I/O pins. The logic allocator steers product terms from the product term array to selected logic macrocells so that no product terms are permanently allocated to a specific logic macrocell.

Abstract: A hierarchical switch matrix in a very high-density programmable logic device (CPLD) interconnects a multiplicity of programmable logic blocks in the CPLD. A new level of functionality coupled with high speed is provided by the hierarchical switch matrix. The hierarchical switch matrix includes three levels, a global switch matrix, a segment switch matrix and a block switch matrix. The block switch matrix provides a high speed signal path for signals within a programmable logic block. The segment switch matrix provides a high speed means of communication for signals within a segment, while the global switch matrix provides a high speed path for communication between segments. The hierarchical switch matrix of this invention provides a fixed, path independent, uniform, predictable and deterministic time delay for each group of signals routed through the hierarchical switch matrix.

Abstract: A programmable logic device (PLD) cell is used to construct a high density high performance programmable logic device (PLD). The PLD cell includes two programmable logic block cells. The PLD cell also includes an I/O cell and an input macrocell. In addition the PLD cell includes a sub-bank of a programmable output switch matrix bank and a sub-bank of a programmable input switch matrix bank. Each programmable logic block cell includes a multiplicity of product terms. At least one product term in the cluster is programmably available to the cluster. When the product term is disconnected from the cluster, the product term is used for control of the polarity of the logic macrocell output signal or asynchronous functions. Thus, the programmably connectable product term can be used for either synchronous or asynchronous operations. If the programmably connectable and disconnectable product term is connected to the product term cluster, the programmable logic block cell is used for synchronous operations.

Abstract: A very high-density complex programmable logic device (CPLD) has a plurality of hierarchical signal paths. The lowest level of the hierarchy is independent from all higher levels. Similarly, an intermediate level is independent from all higher levels and utilizes only resources of the CPLD associated with the lowest and intermediate hierarchical levels. The first hierarchical level resources include a programmable logic block having a plurality of input lines and a plurality of output lines, and a programmable block switch matrix connected to the plurality of input lines of the programmable logic block. The second hierarchical level resources include a programmable segment switch matrix connected to a plurality of input lines of the programmable block switch matrix.

Abstract: A programmable uniform distribution logic allocator enhances the speed, silicon utilization, logic efficiency, logic utilization, and scalability of very high-density CPLDs including the logic allocator. The programmable uniform distribution logic allocator provides a uniform number of product terms to each I/O pin of the CPLDS and the same uniform number of product terms as feedback. However, no product terms are permanently connected to either a particular macrocell or a particular I/O pin. The programmable uniform distribution logic allocator includes a multiplicity of router elements where each router element steers a sum of a selected number of sum-of-product terms from a PAL structure, i.e, a selected number of logic product term-clusters, to a programmably selected logic macrocell. Specifically, the programmable uniform distribution logic allocator has a plurality of input lines, a plurality of output lines and a plurality of programmable router elements.

Abstract: Each programmable logic device in at least two families of high density segmented programmable array logic device utilizes a programmable switch interconnection matrix to couple an array of symmetric programmable logic blocks. Each programmable logic block includes programmable logic macrocells, programmable input/output macrocells, a logic allocator and a programmable product term array. The programmable switch matrix provides centralized global routing with a fixed path independent delay and decouples the logic macrocells from the product term array. The logic allocator decouples the product term array from the logic macrocells, and the I/O macrocells decouple the logic macrocells from the package I/O pins. The logic allocator steers product terms from the product term array to selected logic macrocells so that no product terms are permanently allocated to a specific logic macrocell.

Abstract: A method and on-chip architecture are disclosed for multiplexing signals from selected external interconnect buses to chip internal buses such that bus rerouting can be implemented programmably without substantially affecting timing relations between time-parallel signals of a rerouted bus. An on-chip switch matrix is provided having N input lines crossing with M output lines to provide N times M crosspoints. A plurality of substantially less than N times M programmable interconnect switches (PIP's) are distributed symmetrically among the N.multidot.M crosspoints such that a same first number of interconnect switches (PIP's) are found along each of the N input lines thereby providing equal loading on each input line. The plurality of programmable interconnect switches (PIP's) are further distributed among the N.multidot.M crosspoints such that a same second number of interconnect switches (PIP's) are found along each of the M output lines thereby providing equal loading on each output line.

Abstract: A method and on-chip architecture are disclosed for multiplexing signals from selected external interconnect buses to chip internal buses such that bus rerouting can be implemented programmably without substantially affecting timing relations between time-parallel signals of a rerouted bus. An on-chip switch matrix is provided having N input lines crossing with M output lines to provide N times M crosspoints. A plurality of substantially less than N times M programmable interconnect switches (PIP's) are distributed symmetrically among the N.multidot.M crosspoints such that a same first number of interconnect switches (PIP's) are found along each of the N input lines thereby providing equal loading on each input line. The plurality of programmable interconnect switches (PIP's) are further distributed among the N.multidot.M crosspoints such that a same second number of interconnect switches (PIP's) are found along each of the M output lines thereby providing equal loading on each output line.

Abstract: The programmable logic device (PLD) of this invention includes two or more programmable logic blocks interconnected by a programmable switch matrix that includes a programmable input switch matrix and a programmable centralized switch matrix. Each programmable logic block is coupled to a plurality of programmable I/O macrocells by an output switch matrix. Each programmable I/O macrocell is connected to one of a plurality of I/O pins for the programmable logic block. In one embodiment, an input macrocell couples an I/O macrocell and the associated I/O pin to the programmable input switch matrix. The programmable input switch matrix provides a uniform treatment of all feedback signals to the programmable centralized switch matrix and thereby simplifies signal routing, provides an improved functionality balance, and improved resource utilization within the PLD. The output switch matrix routes output signals from a programmable logic block to any one of a multiplicity of the I/O macrocells.

Abstract: Each programmable logic device in at least two families of high density segmented programmable array logic device utilizes a programmable switch interconnection matrix to couple an array of symmetric programmable logic blocks. Each programmable logic block includes programmable logic macrocells, programmable input/output macrocells, a logic allocator and a programmable product term array. The programmable switch matrix provides centralized global routing with a fixed path independent delay and decouples the logic macrocells from the product term array. The logic allocator decouples the product term array from the logic macrocells, and the I/O macrocells decouple the logic macrocells from the package I/O pins. The logic allocator steers product terms from the product term array to selected logic macrocells so that no product terms are permanently allocated to a specific logic macrocell.

Abstract: A programmable integrated circuit includes configurable logic blocks (CLB's), configurable input/output blocks (IOB's) and a configurable interconnect network for providing program-defined routing of signals between the CLB's and IOB's. Each CLB includes an internal clock selector for selecting a CLB-internal clock and at least one register that is responsive to the selected CLB-internal clock. The configurable interconnect network includes clock-carrying longlines extending in different directions past each CLB for broadcasting clock signals. The broadcast clock signals can originate outside the programmable integrated circuit or such broadcast clock signals can be generated within one or more of the CLB's and thereafter broadcast by way of the clock broadcasting longlines to others of the CLB's.