Abstract: A scheme for reduction of extra standby current induced by process defects is disclosed. After the bit lines and cells with failure due to process defects are repaired by using redundancy in the repairing process, the fuses connected with the pull-transistors coupled to the defect bit lines are disconnected, therefore cutting the leakage current completely. The standby leakage current can be reduced such that the SRAM can pass the standby current test and the yield is improved.

Abstract: A semiconductor memory device with a redundancy circuit includes a reference section, a fuse section and a latch section. The reference section includes a reference resistance and supplies a first current to the reference resistance. The fuse section includes a fuse and supplies a second current to the fuse. The second current is proportional to the first current. The latch section has a threshold and latches a fuse state data based on the threshold and a voltage drop across the fuse. The fuse state data indicates whether or not the fuse is cut.

Abstract: A radiation-tolerant logic circuit includes three similarly configured SRAM-based PLDs. These PLDs work in parallel to provide identical logic functions. To guard against data corruption that can result from radiation-induced upsets, the logic circuit includes a state-comparison circuit that periodically performs a bitwise comparison of the configuration and user data from each of the PLDs; if a bit from one PLD differs from the corresponding bit from the others, the state-comparison circuit sets a flag that indicates that the differing PLD is in error. The erroneous PLD is then reprogrammed using error-free state data. In one embodiment, the error-free state data is read from an error-free PLD.

Abstract: The present invention provides a method and apparatus for high yield improvements in programmable logic devices using redundancy. The present invention concerns a programmable logic device comprising a plurality of routings lines coupled to a plurality of logic blocks when programmed. During programming, a path is routed through the routing lines by programming the selected programmable elements. The selected programmable elements are located at each interconnect point between at least two routing lines or two segments of a routing lines along the path. The programmable elements include at least two interconnect circuits coupled in parallel. The programmable element is successfully programmed when at least one of the interconnect circuits is functional after programming.

Abstract: A programmable cell and a multibit register composed of a plurality of such cells, specifically for performing a coincidence check between a certain code permanently recorded in the cell or cells and a logic configuration present on a pair or on a plurality of pairs of control lines are disclosed. Each cell has two branches connected in OR configuration to a common sensing line of the cell or of the multibit register. The logic states to be tested for coincidence are applied in a complemented form through a pair of lines to each cell, that is to the two branches of the cell. Each cell, permanently programmed in one or the other of its branches, intrinsically performs a comparison between its permanently programmed logic configuration and the configuration of the complemented control lines associated therewith. A great simplification is achieved in the overall circuitry of a redundance or reconfiguration system.

Abstract: A circuit for selecting a block spare in a semiconductor device is designed with a programmable circuit (14), storing an internal address and producing an address match signal AM and a block select signal BS in response to first (A) and second (B) address signals and the internal address. A global spare circuit (28) produces a global spare select signal (GSS), in response to the address match signal. A block spare circuit (34) produces a block spare select signal (BSS), in response to the global spare select signal and the block select signal.

Abstract: A master enable circuit is provided which receives multiple enable signal inputs while matching the redundant decoder enable delay with decoder enable delay. A master enable circuit contains a hard coded master fuse, driver transistor, and a multiple input logic gate. A blown master fuse forces the driver output to an enable state. When the proper select signals are then received by the logic gate, the decoder is enabled to allow selection of the redundant row without introducing a mismatch of redundant and normal line select times.

Abstract: A circuit for selecting a block spare in a semiconductor device is designed with a programmable circuit (14), storing an internal address and producing an address match signal AM and a block select signal BS in response to first (A) and second (B) address signals and the internal address. A global spare circuit (28) produces a global spare select signal (GSS), in response to the address match signal. A block spare circuit (34) produces a block spare select signal (BSS), in response to the global spare select signal and the block select signal.

Abstract: The present invention teaches an integrated circuit ("IC") gate array having improved reliability and increased immunity to deep space interference from electromagnetic radiation, photon energy, and charged particles. In one embodiment of the present invention, the gate array comprises a first and a second logical component, and a first and a second isolation transistor. Both first and second isolation transistors comprise an input, a biasing bus having a voltage potential, and an electrical contact for electrically coupling the biasing bus with the input. Moreover, the gate array comprises a redundant coupling for increasing the immunity of the gate array to charged particles, electromagnetic radiation and photon energy.

Abstract: To provide a type of semiconductor memory device characterized by the fact that the redundancy for the defective memory of defective bits is increased and the area occupied by the redundant memory address decoder on the chip is minimized, thereby reducing the cost of the semiconductor memory device. It has multiple fuse decoders which are commonly connected to the address bus and are programmed for the different addresses, and it has a redundant address decoder which detects coincidence/uncoincidence between the outputs of the two decoders and generates a redundant address coincidence signal, so as to increase the efficiency in repairing the defective memory.

Abstract: In a semiconductor memory having a redundant circuit, a plurality of first normal cells and a plurality of first spare cells are connected to a first pair of data lines, and a plurality of second normal cells and a plurality of second spare cells are connected to a second pair of data lines. Both pairs of data lines are connected to an output data line through a selecting amplifier. A normal cell is selected based on a combination of NGWL1, NGWL2, . . . with BLK1, BLK2, both NGWL1, NGWL2, . . . and BLK1, BLK2 being supplied from a decoder, and a spare cell is selected based on a combination of the BLK1, BLK2 supplied from the decoder with SGWL1, SGWL2, . . . supplied from a redundancy judging circuit. A second spare cell is selected when a first normal cell is selected, and a first spare cell is selected when a second normal cell is selected. Only at the time when a spare address is entered, one of the SGWL1, SGWL 2, . . . is raised.

Abstract: A fuse-programmable control circuit has a master control circuit with a first fusible link that controls the feeding of power to a fuse-programmable memory. If output of signals from the fuse-programmable memory is not required, the first fusible link is cut. If output of signals from the fuse-programmable memory is required, the first fusible link is left uncut and the fuse-programmable memory is programmed by cutting one fusible link in each of a number of pairs of fusible links. In either case, no current can flow through the fuse-programmable control circuit.

Abstract: A programmable logic device is provided that has redundant circuitry. When a portion of the programmable logic device circuitry is found to be defective, the redundant circuitry is switched into use in place of the defective circuitry by programming appropriate portions of the circuitry of the programmable logic device. The programmable logic device is arranged in rows and columns of programmable logic containing logic array blocks, which a user selectively configures by loading programming data into vertical and horizontal programming blocks. Programming blocks are used to program the logic array blocks and various associated logic circuitry. When the redundant circuitry is switched into place, the programming data is redirected to the appropriate programming blocks, so that the device functions identically, regardless of whether or not the redundant circuitry is used.