摘要:
A field programmable gate array (FPGA) includes a distributed switch matrix for programmably connecting the various routing conductors. The distributed switch matrix comprises groups of additional conductors (e.g., 305, 306, 307), referred to as "Switching R-nodes". The Switching R-nodes programmably connect selected ones of the (e.g, horizontal) routing conductors (e.g., 301, 302, 303, 304) to other selected ones of the (e.g., vertical) routing conductors (e.g., 308, 309, 310, 311, 312). In this manner, the direct connection between the routing conductors may be avoided, allowing for a reduced number of programmable interconnect devices. In one preferred embodiment, a nibble-mode architecture is used, wherein four data conductors are provided for each group of routing conductors, with other multiples-of-four data conductors also being advantageous.
摘要:
A field configurable function element offers multi-function use of memory cells by organizing the cells in memory banks and by providing internal configurable interconnections of the memory banks. A versatile logic function configuration is obtained by storing the truth table of the desired logic functions in the memory cells. An arithmetic functions configuration is obtained by internally interconnecting the memory cells. A read/write memory function configuration is obtained by adding write address decoding, write enablement capability and input data leads. The configuration permits a parallel writing and reading of the memory cells, thereby effectuating a two- port memory operation. An added set of latches connected to the configurable function element and a configurable routing network connected to the inputs of the configurable function element, to the output of the configurable function element and to the output of the latches, form a powerful device that can be easily configured to any one of the three primary modes (logic, arithmetic and memory). A generalized routing fabric coupled to the routing network provides for configurable connections to other configurable function devices. To minimize the load that such a device may present to the routing fabric because of the various configurable interconnections that it can effect, the input leads from the routing fabric to the routing network in configurable function device are all multiplexed to one, or a few contact points, via an intermediate level of routing.
摘要:
A field programmable gate array includes a dedicated path (606) which directly connects an I/O pad (604) to a selected register (603) in the array of programmable function units (602). For example, a direct connection (i.e., without a configurable interconnect point) is provided from an I/O pad, through an input driver (605), to the input of a selected register in a given PFU. Either this same path, or alternatively a different path, may also be used to directly connect a register output from a given PFU to an I/O pad, through an output driver. This technique avoids the need for special I/O registers in the programmable input/output cells, thereby increasing the flexibility of use and ease of design of the FPGA.
摘要:
A field programmable array of application circuitry (C1,C2,...) is programmed (or reprogrammed) by first applying application circuitry power supply (AV dd =5v) to the application circuitry, and then applying a binary digital data signal (D0/D1) through the source-drain path of an access transistor (N3) in its on condition to the SRAM that controls the on/off condition of its associated controlled pass transistor (N4). This SRAM is one of a row-column array of similar SRAMs, and the access transistors for all SRAMs on the same row are similarly supplied with data signals through access transistors. The pass transistor determines whether application circuitry interconnection points (A1,A2), are going to be connected after the programming (or reprogramming) is terminated. While the data signal (D0/D1) is applied to the SRAM, and the power supply (PV DD ) for the SRAM is maintained at an intermediate level (3v) below the level of the application circuitry power supply voltage (AV dd =5v) and below the high binary level (D1), a row-select pulse (S) is applied to a control terminal of the access transistor, as well as to all control terminals of access transistors for accessing all other SRAMs on the same row. The row-select pulse (S) is then terminated and the SRAMs on other rows (if need be) are similarly written (or re-written). Then the power supply (PV DD ) for the SRAMs is increased to a level (PV DD =6v) advantageously higher, by a threshold of the pass transistor (N4), than that of the application circuitry (AV dd =5v), to reduce both voltage drops and power losses in pass transistors.
摘要:
A field programmable array of application circuitry (C1,C2,...) is programmed (or reprogrammed) by first applying application circuitry power supply (AV dd =5v) to the application circuitry, and then applying a binary digital data signal (D0/D1) through the source-drain path of an access transistor (N3) in its on condition to the SRAM that controls the on/off condition of its associated controlled pass transistor (N4). This SRAM is one of a row-column array of similar SRAMs, and the access transistors for all SRAMs on the same row are similarly supplied with data signals through access transistors. The pass transistor determines whether application circuitry interconnection points (A1,A2), are going to be connected after the programming (or reprogramming) is terminated. While the data signal (D0/D1) is applied to the SRAM, and the power supply (PV DD ) for the SRAM is maintained at an intermediate level (3v) below the level of the application circuitry power supply voltage (AV dd =5v) and below the high binary level (D1), a row-select pulse (S) is applied to a control terminal of the access transistor, as well as to all control terminals of access transistors for accessing all other SRAMs on the same row. The row-select pulse (S) is then terminated and the SRAMs on other rows (if need be) are similarly written (or re-written). Then the power supply (PV DD ) for the SRAMs is increased to a level (PV DD =6v) advantageously higher, by a threshold of the pass transistor (N4), than that of the application circuitry (AV dd =5v), to reduce both voltage drops and power losses in pass transistors.
摘要:
A field configurable function element offers multi-function use of memory cells by organizing the cells in memory banks and by providing internal configurable interconnections of the memory banks. A versatile logic function configuration is obtained by storing the truth table of the desired logic functions in the memory cells. An arithmetic functions configuration is obtained by internally interconnecting the memory cells. A read/write memory function configuration is obtained by adding write address decoding, write enablement capability and input data leads. The configuration permits a parallel writing and reading of the memory cells, thereby effectuating a two- port memory operation. An added set of latches connected to the configurable function element and a configurable routing network connected to the inputs of the configurable function element, to the output of the configurable function element and to the output of the latches, form a powerful device that can be easily configured to any one of the three primary modes (logic, arithmetic and memory). A generalized routing fabric coupled to the routing network provides for configurable connections to other configurable function devices. To minimize the load that such a device may present to the routing fabric because of the various configurable interconnections that it can effect, the input leads from the routing fabric to the routing network in configurable function device are all multiplexed to one, or a few contact points, via an intermediate level of routing.
摘要:
A field programmable gate array includes a dedicated path (606) which directly connects an I/O pad (604) to a selected register (603) in the array of programmable function units (602). For example, a direct connection (i.e., without a configurable interconnect point) is provided from an I/O pad, through an input driver (605), to the input of a selected register in a given PFU. Either this same path, or alternatively a different path, may also be used to directly connect a register output from a given PFU to an I/O pad, through an output driver. This technique avoids the need for special I/O registers in the programmable input/output cells, thereby increasing the flexibility of use and ease of design of the FPGA.