Abstract:
An SRAM cell eliminates the p-channel pull-up resistors to decrease its physical size. A tracking circuit generates a control signal used to ensure that the memory state is preserved during the idle state. The control signal controls the wordline voltage during the idle state to vary the leakage through the access transistors to ensure that current into the node through the access device is not exceeded by leakage current out of the output nodes through the storage devices. The tracking circuit control signal can also be used to vary the well to substrate bias voltage of the storage devices to decrease the leakage through the storage devices. The control signal can also be used to bias the supply rail voltage to which the storage devices are directly coupled to decrease the amount of leakage through the storage devices. The tracking circuit comprises a number of half configured memory cells that are placed in a state which mimics the stored state in a normal memory cell that would degrade during the idle state. A differential amplifier detects when the output state of the dummy cells have fallen below a predetermined reference voltage. The differential amplifier generates the control signal at a level required to restore the output state to at or near the reference voltage.
Abstract:
The present invention relates to a system and method adapted to increase memory cell and memory architecture design yield. The present invention includes memory architecture having a decoder and a multi-bank memory. The decoder is adapted to decode addresses. The multi-bank memory interacts with the decoder, wherein the multi-bank memory includes at least one output data bit adapted to complete a word for a failing bank in the multi-bank memory.
Abstract:
The present invention relates to a system and method for increasing the manufacturing yield of a plurality of memory cells used in cell arrays. A programmable fuse, having both hardware and software elements, is used with the plurality of memory cells to indicate that at least one memory cell is unusable and should be shifted out of operation. The software programmable element includes a programmable register adapted to shift in an appropriate value indicating that at least one of the memory cells is flawed. The hardware element includes a fuse gated with the programmable register. Shifting is indicated either by software programmable fuse or hard fuse. Soft fuse registers may be chained together forming a shift register.
Abstract:
In a memory module having a designated group of memory cells assigned to represent a logical portion of the memory structure, a memory redundancy circuit having a redundant group of memory cells; and a redundancy controller coupled with the designated group and the redundant group. The redundancy controller, which can include a redundancy decoder, assigns the redundant group to the logical portion of the memory structure in response to a preselected memory group condition, e.g., a “FAILED” memory group condition. The redundancy controller also can include selectable switches, for example, fuses, which can encode the preselected memory group condition. The designated group of memory cells and the redundant group of memory cells can be a memory row, a memory column, a preselected portion of a memory module, a selectable portion of a memory module, a memory module, or a combination thereof.
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:
A limited swing driver with a pass transistor coupled between a memory cell and an associated bitline; an inverter, its output coupled to the gate of the pass transistor, and its input coupled with the memory cell. A memory node is formed at the juncture of the inverter input and the memory cell forming a memory node. The driver also includes a discharge transistor coupled between the memory node and ground. The discharge transistor is driven by an input on the discharge transistor gate. It is preferred that the discharge transistor being programmed to produce a limited swing voltage at the memory node. It is desirable that the limited swing voltage be less than about 350 mV, and it is preferable that the limited swing voltage be between about 300 mV and about 200 mV. In addition, the limited swing voltage driver can include a tri-state output enable isolating the memory node from the bitline, particularly if the bitline is a shared or multiplexed bitline; and a self-reset circuit resetting the driver to a predetermined signal state.
Abstract:
Power-on-reset (POR) circuits for resetting memory devices, and related circuits, systems, and methods are disclosed. In one embodiment, a POR circuit is provided. The POR circuit is configured to receive as input, a plurality of decoded address outputs from at least one memory decoding device. The POR circuit is further configured to generate a POR reset if any of the plurality of decoded address outputs are active. As a result, memory decoding device latches can be reset to a known, default condition to avoid causing an unintentional word line selection in the memory during power-on state before an external reset is available. Because the POR circuit can generate the POR reset without need of an external reset, the memory decoding devices can be reset quickly to allow for quicker availability of memory after a power-on condition.
Abstract:
The present invention relates to a system and method for adjusting timing of memory access operations to a memory block. In one embodiment, a controller may be in communication with a memory block. The controller may be adapted to adjust timing of a memory access operation to the memory block by extending a portion of a clock pulse to compensate for delay associated with the memory block. The delay may correspond to a predecoder delay or a global decoder delay. The clock pulse may be a read clock pulse or a write clock pulse. In one embodiment, the controller may be adapted to adjust timing of a read clock pulse differently from a write clock pulse
Abstract:
Read and write operations of a non-volatile memory (NVM) bitcell have different optimum parameters resulting in a conflict during design of the NVM bitcell. A single bitline in the NVM bitcell prevents optimum read performance. Read performance may be improved by splitting the read path and the write path in a NVM bitcell between two bitlines. A read bitline of the NVM bitcell has a low capacitance for improved read operation speed and decreased power consumption. A write bitline of the NVM bitcell has a low resistance to handle large currents present during write operations. A memory element of the NVM bitcell may be a fuse, anti-fuse, eFUSE, or magnetic tunnel junction. Read performance may be further enhanced with differential sensing read operations.
Abstract:
In one embodiment, a DRAM is provided that includes: a word line intersecting with a pair of bit lines, the DRAM including a memory cell at each intersection, each memory cell including an access transistor adapted to couple a storage cell to the corresponding bit line if its gate voltage is raised; and a word line compensation circuit adapted to compensate for a capacitively-coupled voltage increase on the corresponding bit line if the access transistor's gate voltage is raised.