Abstract: The invention provides a circuit that can observe data within shift registers without altering the data. The circuit includes selectors connected to the inputs and outputs of the shift registers. The selectors selectively connect the input with the output of a selected shift register to form a wiring loop for the selected shift register. A control device connected to the wiring loop uses the wiring loop to cause the data to be continually transferred from the output of the selected shift register to the input of the selected shift register and back through the selected shift register in a circular manner. The control device includes a counter used for determining the length of a selected shift register and a set of registers to store, for future use when rotating data in the shift registers, the length of each shift register. The control device also includes a data output accessible from outside the circuit.

Abstract: A bit fail map circuit accurately generates a bit fail map of an embedded memory such as a DRAM by utilizing a high speed multiplied clock generated from a low-speed Automated Test Equipment (ATE) tester. The circuit communicates between the ATE tester, the embedded memory under test, Built-In Self-Test (BIST) and Built-In Redundancy Analysis (BIRA). An accurate bit fail map of an embedded DRAM memory is provided by pausing the BIST test circuitry at a point when a fail is encountered, namely a mismatch between BIST expected data and the actual data read from the array, and then shifting the bit fail data off the chip using the low-speed ATE tester clock. Thereafter, the high-speed test is resumed from point of fail by again running the BIST using the high-speed internal clock, to provide at-speed bit Fail Maps.

Abstract: A system for performing device-specific testing and acquiring parametric data on custom integrated circuits, for example ASICs, such that each chip is tested individually without excessive test time requirements, additional silicon, or special test equipment. The testing system includes a device test structure integrated into unused backfill space in an ASIC design which tests a set of dummy devices that are identical to some of those of the ASIC. The device test structure includes control logic for designating the type of test and which device types to activate (e.g. pFETs or nFETs), a protection circuit for protecting the SPM when the test is inactive, an isolation circuit for isolating the devices under test (DUT) from any leakage current during test, and a decode circuit for providing test input (e.g. voltages) to the DUT. By controlling which devices to test and the voltage conditions of those devices, the system calculates the relative product yield and health of the line on a die by die basis.

Abstract: A system for performing device-specific testing and acquiring parametric data on custom integrated circuits, for example ASICs, such that each chip is tested individually without excessive test time requirements, additional silicon, or special test equipment. The testing system includes a device test structure integrated into unused backfill space in an ASIC design which tests a set of dummy devices that are identical to some of those of the ASIC. The device test structure includes control logic for designating the type of test and which device types to activate (e.g. pFETs or nFETs), a protection circuit for protecting the SPM when the test is inactive, an isolation circuit for isolating the devices under test (DUT) from any leakage current during test, and a decode circuit for providing test input (e.g. voltages) to the DUT. By controlling which devices to test and the voltage conditions of those devices, the system calculates the relative product yield and health of the line on a die by die basis.

Abstract: A differential fuse sensing system includes a fuse leg configured for introducing a sense current through an electrically programmable fuse (eFUSE) to be sensed, and a differential sense amplifier having a first input node coupled to the fuse leg and a second node coupled to a reference voltage. The fuse leg further includes a current supply device controlled by a variable reference current generator configured to generate an output signal therefrom such that the voltage on the first input node of the sense amplifier is equal to the voltage on the second input node of the sense amplifier whenever the resistance value of the eFUSE is equal to the resistance value of a programmable variable resistance device included within the variable reference current generator.

Abstract: Circuitry that includes a voltage controller (224) for providing a variable gate signal (220) for controlling the gate of a programming transistor (212) used in conjunction with programming an electrically programmable fuse (“eFuse”) (204) of an integrated circuit (200). The voltage controller adjusts the gate signal depending upon whether the circuitry is in an eFuse programming mode or an eFuse resistance measuring mode. The voltage controller may optionally include a voltage tuner (252) for tuning the gate signal to account for operating variations in the programming transistor caused by manufacturing variations.

Abstract: An apparatus for sensing the state of a programmable resistive memory element device includes a latch device is coupled to a fuse node and a reference node, the fuse node included within a fuse leg and the reference node configured within a reference resistance leg. The latch device is configured to detect a differential signal developed between the reference node and the fuse node as the result of sense current passed through the fuse leg and the reference resistance leg. The fuse and reference resistance legs are further configured for first and second sensing modes, wherein the second sensing mode utilizes a different level of current than the first sensing mode.

Abstract: A method and circuit design for enabling both shift path and scan path functionality with a single port LSSD latch designed for scan path functionality only, without increasing the device's internal real estate and without substantial increase in overall device real estate. The circuit design eliminates the need for additional logic components to be built into the internal circuitry of the device and also eliminates the cost of providing dual port LSSD latches within the device. Implementation of the invention involves providing a unique configuration of low level logic components as input circuitry that is coupled to a pair of single port LSSD latches that operate as the input latches for the device. The low level logic components accomplishes the splitting of scan chain inputs and shift chain inputs to the input latches and thus enables the single ported LSSD latches to operate with similar functionality as dual ported LSSD latches.

Abstract: A system, method and program product for adjusting an environmental variable of a fuse blow of an electronic fuse are disclosed. A mimic NFET is coupled to a fuse blow source voltage line, a fuse blow gate voltage line, and a chip ground in the same manner as the electronic fuse, except that the mimic NFET is not attached to a poly fuse link. The on current (ion) and off current (ioff) of the mimic NFET are measured to determine a blow current of the electronic fuse. The environmental variable is adjusted based on the determined blow current.

Abstract: The invention provides a circuit that can observe data within shift registers without altering the data. The circuit includes selectors connected to the inputs and outputs of the shift registers. The selectors selectively connect the input with the output of a selected shift register to form a wiring loop for the selected shift register. A control device connected to the wiring loop uses the wiring loop to cause the data to be continually transferred from the output of the selected shift register to the input of the selected shift register and back through the selected shift register in a circular manner. The control device includes a counter used for determining the length of a selected shift register and a set of registers to store, for future use when rotating data in the shift registers, the length of each shift register. The control device also includes a data output accessible from outside the circuit.

Abstract: An electrical fuse circuit design for reducing the testing time for a semiconductor device manufactured with redundant eFuse circuitry. A two-to-one multiplexer (MUX) is provided at each eFuse circuit in addition to the fuse latch and pattern latch. Information on which fuse is to be blown is stored in the fuse's pattern latch. The output of the pattern latch is ANDed with a program input to provide a select signal for the MUX. Based on the select signal, the MUX allows the shifted “1” to either go to the next latch in the shift chain or bypass the next latch or latches in the shift chain when the next fuse(s) is not to be blown. Accordingly, the invention enables only those fuse latches associated with fuses that are to be blown to hold up the propagation of the shifted “1” to the next eFuse circuits.

Abstract: A fuse latch circuit with a current reference generator is described where the resistive switch point of the latch is stabilized against effects of manufacturing processing, operating voltage and temperature. A digital control word is used to select the desired resistive trip point of the fuse latch and compensation within the reference generator maintains this resistive trip point with high accuracy. The variable resistive trip point is set to a first value at test and then to a second value in use condition to enhance operating margin, and soft error immunity.

Abstract: A self-timed data transmission system includes a data bit group defined by at least two data bits to be transmitted from a corresponding plurality of transmitting storage elements. A corresponding plurality of data receiving storage elements receives the data transmitted from said transmitting storage elements. Encoding logic is used for encoding the transmitted data from the transmitting storage elements, wherein the encoded transmitted data is coupled to a plurality of data lines. The encoding logic is further configured so as to result in only one of the plurality of data lines being activated during a given data transmission cycle.

Abstract: A modular Digital Locked Loop (DLL) architecture capable of generating a plurality of multiple phase clock signals, having particular applicability to synchronization of embedded DRAM systems with on chip timing. The architecture comprises a single core frequency locking circuit that includes a delay element with control logic and locking circuitry capable of locking the DLL system clock frequency to an external reference clock, and a plurality of secondary phase locking circuits capable of synchronizing a plurality of internal clock signals to any phase of the external reference clock.

Abstract: A method and circuit for timing the start of a precharge period in an eDRAM. The circuit including: a delayed lock loop circuit for receiving a clock signal and generating a control signal for adjusting an internal delay of the clock signal; and means for generating a delayed clock signal in response to the control signal. The means for generating the delayed clock signal is a multiple stage delay circuit, each stage of the multiple delay stage circuit connected in series and each stage individually responsive to the control signal.

Abstract: A control circuit for a memory array device having one or more memory storage cells associated therewith includes a true bit-line and a complementary bit-line coupled to the one or more memory storage cells. A sense amplifier is coupled to the true and complementary bit-lines, the sense amplifier being configured to amplify a small voltage difference between the true bit-line and the complementary bit-line to a full level signal at predetermined high and low logic voltage levels. A bit-switch pair selectively couples the bit-lines and said sense amplifier to fan-in circuitry, and is further configured so as to couple the fan-in circuitry to the true and complementary bit-lines prior to the activation of a wordline associated with a selected cell for a write operation thereto. Thereby, the write operation to the selected cell is commenced prior to the completion of time associated with signal development on the true and complementary bit-lines.

Abstract: A chip repair system designed for automated test equipment independent application on many unique very dense ASIC devices in a high turnover environment is disclosed. During test, the system will control on chip built-in self-test (BIST) engines collect and compress repair data, program fuses and finally decompress and reload the repair data for post fuse testing. In end use application this system decompresses and loads the repair data at power-up or at the request of the system.

Abstract: A growable multibank DRAM macro is achieved with a flexible multibank interface which can be grown without redesign and without change of appearance/behavior to the customer. The interface is preferably characterized by the presence of bank select inputs (pins) which permit selection of one or more banks of the macro. The banks preferably each have respective row decode circuitry and respective limited repair redundancy.

Abstract: A chip repair system designed for automated test equipment independent application on many unique very dense ASIC devices in a high turnover environment is disclosed. During test, the system will control on chip built-in self-test (BIST) engines collect and compress repair data, program fuses and finally decompress and reload the repair data for post fuse testing. In end use application this system decompresses and loads the repair data at power-up or at the request of the system.

Abstract: A growable multibank DRAM macro is achieved with a flexible multibank interface which can be grown without redesign and without change of appearance/behavior to the customer. The interface is preferably characterized by the presence of bank select inputs (pins) which permit selection of one or more banks of the macro. The banks preferably each have respective row decode circuitry and respective limited repair redundancy.