Abstract: Circuits for measuring and characterizing random variations in device characteristics of integrated circuit devices.

Abstract: Circuits and methods for measuring and characterizing random variations in device characteristics of semiconductor integrated circuit devices, which enable circuit designers to accurately measure and characterize random variations in device characteristics (such as transistor threshold voltage) between neighboring devices resulting from random sources such as dopant fluctuations and line edge roughness, for purposes of integrated circuit design and analysis. In one aspect, a method for characterizing random variations in device mismatch (e.g., threshold voltage mismatch) between a pair of device (e.g., transistors) is performed by obtaining subthreshold DC voltage characteristic data for the device pair, and then determining a distribution in voltage threshold mismatch for the device pair directly from the corresponding subthreshold DC voltage characteristic data.

Abstract: A memory cell comprises a wordline, a first digital inverter with a first input and a first output, and a second digital inverter with a second input and a second output. Moreover, the memory cell further comprises a first feedback connection connecting the first output to the second input, and a second feedback connection connecting the second output to the first input. The first feedback connection comprises a first resistive element and the second feedback connection comprises a second resistive element. What is more, each digital inverter has an associated capacitance. The memory cell is configured such that reading the memory cell includes applying a read voltage pulse to the wordline. In addition, the first and second resistive elements are configured such that the first and second feedback connections have resistance-capacitance induced delays longer than the applied read voltage pulse.

Abstract: A memory cell comprises a wordline, a first digital inverter with a first input and a first output, and a second digital inverter with a second input and a second output. Moreover, the memory cell further comprises a first feedback connection connecting the first output to the second input, and a second feedback connection connecting the second output to the first input. The first feedback connection comprises a first resistive element and the second feedback connection comprises a second resistive element. What is more, each digital inverter has an associated capacitance. The memory cell is configured such that reading the memory cell includes applying a read voltage pulse to the wordline. In addition, the first and second resistive elements are configured such that the first and second feedback connections have resistance-capacitance induced delays longer than the applied read voltage pulse.

Abstract: A memory cell comprises a wordline, a first digital inverter with a first input and a first output, and a second digital inverter with a second input and a second output. Moreover, the memory cell further comprises a first feedback connection connecting the first output to the second input, and a second feedback connection connecting the second output to the first input. The first feedback connection comprises a first resistive element and the second feedback connection comprises a second resistive element. What is more, each digital inverter has an associated capacitance. The memory cell is configured such that reading the memory cell includes applying a read voltage pulse to the wordline. In addition, the first and second resistive elements are configured such that the first and second feedback connections have resistance-capacitance induced delays longer than the applied read voltage pulse.

Abstract: A memory cell comprises a wordline, a first digital inverter with a first input and a first output, and a second digital inverter with a second input and a second output. Moreover, the memory cell further comprises a first feedback connection connecting the first output to the second input, and a second feedback connection connecting the second output to the first input. The first feedback connection comprises a first resistive element and the second feedback connection comprises a second resistive element. What is more, each digital inverter has an associated capacitance. The memory cell is configured such that reading the memory cell includes applying a read voltage pulse to the wordline. In addition, the first and second resistive elements are configured such that the first and second feedback connections have resistance-capacitance induced delays longer than the applied read voltage pulse.

Abstract: A multi-port register file, integrated circuit (IC) chip including one or more multi-port register files and method of reading data from the multi-port register file. The supply to storage latches in multi-port register file is selectively bootstrapped above the supply voltage during accesses.

Abstract: Circuits and methods are provided to implement low voltage, higher performance semiconductor memory devices such as CMOS static random access memory (SRAM) or multi-port register files. For example, circuits and methods are provided for dynamically adjusting power supply and/or ground line voltages that are applied to the memory cells during different modes of memory operation to enable low voltage, high performance operation of the memory devices.

Abstract: A multi-port register file, integrated circuit (IC) chip including one or more multi-port register files and method of reading data from the multi-port register file. The supply to storage latches in multi-port register file is selectively bootstrapped above the supply voltage during accesses.

Abstract: A hybrid interconnect structure that possesses a higher interconnect capacitance in one set of regions than in other regions on the same microelectronic chip is described. Several methods to fabricate such a structure are provided. Circuit implementations of such hybrid interconnect structures are described that enable increased static noise margin and reduce the leakage in SRAM cells and common power supply voltages for SRAM and logic in such a chip. Methods that enable combining these circuit benefits with higher interconnect performance speed and superior mechanical robustness in such chips are also taught.

Abstract: A quasi-static random access memory cell exhibits increased READ mode operation stability by statically storing the cell logic value during idle periods and dynamically storing the cell logic value during READ mode operation.

Abstract: Loadless 4T SRAM cells, and methods for operating such SRAM cells, which can provide highly integrated semiconductor memory devices while providing increased performance with respect to data stability and increased I/O speed for data access operations. A loadless 4T SRAM cell comprises a pair of access transistors and a pair of pull-down transistors, all of which are implemented as N-channel transistors (NFETs or NMOSFETS). The access transistors have lower threshold voltages than the pull-down transistors, which enables the SRAM cell to effectively maintain a logic “1” potential during standby. The pull-down transistors have larger channel widths as compared to the access transistors, which enables the SRAM cell to effectively maintain a logic “0” potential at a given storage node during a read operation.

Abstract: Circuits and methods for controlling data access operations in memory devices such as SRAM (static random access memory) devices. The circuits and methods provide timing and control for memory access operations by propagating a control pulse along a decode path from which a sequence of control pulses are generated at points in the decode path to synchronize activation of wordlines and sense amplifiers and precharge/equalization of bit lines. Preferably, an address gated pulse schema is implemented to synchronize and restrict switching activity spatially and temporally to only regions of a memory array that are being accessed, and for limited periods of time just sufficient to generate signals for read or write operations. Advantageously, the circuits and methods enable SRAM cell delays to track CMOS gate delays more closely at low voltages and reduce switching power by restricting switching transitions only to the regions of memory that are accessed.

Abstract: Loadless 4T SRAM cells, and methods for operating such SRAM cells, which can provide highly integrated semiconductor memory devices while providing increased performance with respect to data stability and increased I/O speed for data access operations. A loadless 4T SRAM cell comprises a pair of access transistors and a pair of pull-down transistors, all of which are implemented as N-channel transistors (NFETs or NMOSFETS). The access transistors have lower threshold voltages than the pull-down transistors, which enables the SRAM cell to effectively maintain a logic “1” potential during standby. The pull-down transistors have larger channel widths as compared to the access transistors, which enables the SRAM cell to effectively maintain a logic “0” potential at a given storage node during a read operation.

Abstract: Circuits and methods for measuring and characterizing random variations in device characteristics of semiconductor integrated circuit devices, which enable circuit designers to accurately measure and characterize random variations in device characteristics (such as transistor threshold voltage) between neighboring devices resulting from random sources such as dopant fluctuations and line edge roughness, for purposes of integrated circuit design and analysis. In one aspect, a method for characterizing random variations in device mismatch (e.g., threshold voltage mismatch) between a pair of device (e.g., transistors) is performed by obtaining subthreshold DC voltage characteristic data for the device pair, and then determining a distribution in voltage threshold mismatch for the device pair directly from the corresponding subthreshold DC voltage characteristic data.

Abstract: A memory device has a memory cell including a plurality of active devices, which can be switched on by an applied threshold voltage. A power line is coupled to at least one storage node by one of the active devices. One other of the active devices couples a virtual ground to the storage node. Potentials of the power line and the virtual ground cause the plurality of active devices to be selectively operated in near subthreshold and/or superthreshold regimes in accordance with a mode of operation.

Abstract: Circuits and methods for controlling data access operations in memory devices such as SRAM (static random access memory) devices. The circuits and methods provide timing and control for memory access operations by propagating a control pulse along a decode path from which a sequence of control pulses are generated at points in the decode path to synchronize activation of wordlines and sense amplifiers and precharge/equalization of bit lines. Preferably, an address gated pulse schema is implemented to synchronize and restrict switching activity spatially and temporally to only regions of a memory array that are being accessed, and for limited periods of time just sufficient to generate signals for read or write operations. Advantageously, the circuits and methods enable SRAM cell delays to track CMOS gate delays more closely at low voltages and reduce switching power by restricting switching transitions only to the regions of memory that are accessed.