Abstract:
A hierarchical memory structure having memory cells, and sense amplifiers and decoders coupled with the memory cells to form first tier memory module, and subsequent tiers being formed by having (n−1)-tier memory modules, which are coupled with (n)-tier sense amplifiers and (n)-tier decoders. Also provided are a single-ended sense amplifier having sample-and-hold reference, and a charge-share limited-swing-driver sense amplifier; an asynchronously-resettable decoder; a wordline decoder having row redundancy; a redundancy device having redundant memory cells operated by a redundancy controller; a diffusion replica delay circuit; a high-precision delay measurement circuit; and a data transfer bus circuit imposing a limited voltage swing on a data bus. Methods are provided for a write-after-read operation without an interposed precharge cycle, and write-after-write operation with an interposed precharge cycle are provided, either operation being completed in less than one memory access cycle.
Abstract:
The present invention relates to a synchronous self timed memory device. The device includes a plurality of memory cells forming a cell array, at least one local decoder interfacing with the cell array, at least one local sense amplifier and at least one local controller. The local sense amplifier interfaces with at least the decoder and cell array, and is adapted to precharge and equalize at least one line coupled thereto. The local controller interfaces with and coordinates the activities of at least the local decoder and sense amplifier.
Abstract:
The present invention relates to a system and method for applying a stress to a hierarchical memory structure in parallel, testing the memory structure for weak defects. The present invention includes writing a logic 0 into all the memory cells in a memory structure. All the high address predecoded lines and alternating predecoded lines for the lowest address are enabled. A voltage drop between neighboring wordlines and bitlines is affected. A logic I is written into all the memory cells in the memory structure. An opposite voltage polarity is caused on the bitlines due to the logic 1 in the memory cells. A reverse voltage polarity stress is achieved on the wordlines by flipping the state of the lowest predecoded line (i.e., by changing the input address corresponding to that line.
Abstract:
A digital memory system (30) includes a memory cell (52), a bit line (50), a transfer gate (60) a reference voltage generator (40), a sense amplifier (70) and a control circuit (80). The control circuit precharges the bit line to a bit line precharge voltage, which is sampled and stored. A corresponding reference voltage is generated after the bit line is isolated. The bit line and reference voltage are coupled to the sense amplifier so that a voltage is received based on charge stored in the memory cell. The sense amplifier then is isolated from the bit line and reference voltage and the sense amplifier is energized so that an output voltage is derived from the charge and reference voltage.
Abstract:
A method of implementing a diffusion replica delay circuit is provided in a device with a device capacitance and operational characteristics. A diffusion replica capacitor is coupled to the device and is capable of storing a predetermined replica charge representative of a selected device operational characteristic, and a diffusion replica transistor is coupled with the diffusion replica capacitor, and is coupled between the diffusion replica capacitor and a charge sink. The transistor is disposed to control the magnitude of the predetermined replica charge.
Abstract:
The present invention relates to a system and method for providing distributed, highly configurable modular predecoding. The system includes a hierarchical memory structure, including a predecoder adapted to perform a first layer of address predecoding and at least one local predecoder interacting with the global predecoder and adapted to perform a second layer of address predecoding.
Abstract:
A high-precision delay measurement circuit delivers exceptionally accurate time measurement, for example, a half-gate delay. The high-precision delay measurement circuit has a multi-stage ring oscillator coupled with multiple oscillation signal detectors, which can be counters and signal edge detection circuits, which respectively count the number of oscillations by the circuit, and determine the extent to which a particular oscillation signal propagated within the oscillator. Some oscillation counters, particularly those disposed between the stages of the oscillator are dual-edge detection counters. The high precision delay measurement circuit can have a control signal output which can constrain a limited voltage swing signal.
Abstract:
A high speed low power data transfer bus circuit that reduces bus power consumption by imposing a limited, controlled voltage swing on the associated data bus. In one embodiment, an inverter is coupled with a pMOS pass transistor and an nMOS discharge transistor, and the combination is coupled with a data bus. The discharge transistor and pass transistor can be programmed to provide a preselected bus operational characteristics. In another embodiment, multiple nMOS discharge transistors can be coupled to the data bus via the pass transistor, with each of the discharge transistors being selectively programmed to provide additional preselected bus operational characteristics, multiple, programmable discharge transistors, thus selectably imposing encoded and multilevel logic signals on the data bus. In another embodiment, a bidirectional data transfer bus circuit couples two data busses while imposing a limited, controlled voltage swing during the transfer. One preferred embodiment couples a first data bus and a second data bus with cross-linked inverters. Interposed between the inverters, and its associated bus, is a respective pMOS pass transistor. Also, coupled between each input node and ground, is a signal discharge transistor, preferably nMOS, which facilitates data transfer between the buses. Each of the inverters is coupled with a clocked charge/discharge circuit, preferably using a common clock signal.
Abstract:
In a particular embodiment, an apparatus includes a one-time programmable (OTP) memory circuit configured to be responsive to a programming voltage. The OTP memory circuit includes an OTP memory array including OTP memory cells, a first power switch configured to decouple the OTP memory array from the programming voltage, and a second power switch configured to decouple a subset of the OTP memory cells from the programming voltage.
Abstract:
A memory includes at least first and second banks of single-port memory elements, a first local controller adapted to send read and write instructions to the first memory bank, and a second local controller adapted to send read and write instructions to the second memory bank. A global controller is configured to receive first and second memory addresses and a first indication of an operation to be performed at the first memory addresses and a second indication of an operation to be performed at the second memory address and to instruct the first local controller to perform the first indicated operation at the first memory address and to instruct the second local controller to perform the second indicated operation at the second memory address at the same time.