Patent application number | Description | Published |
20080285367 | METHOD AND APPARATUS FOR REDUCING LEAKAGE CURRENT IN MEMORY ARRAYS - Techniques for reducing leakage current in memory arrays are described. A memory array has multiple rows and multiple columns of memory cells. Bit lines are coupled to the columns of memory cells, and word lines are coupled to the rows of memory cells. The bit lines have disconnected paths to a power supply and float during a sleep mode for the memory array. The bit lines may be coupled to (i) precharge circuits used to precharge the bit lines prior to each read or write operation, (ii) pass transistors used to couple the bit lines to sense amplifiers for read operations, and (iii) pull-up transistors in drivers used to drive the bit lines for write operations. The precharge circuits, pass transistors, and pull-up transistors are turned off during the sleep mode. The word lines are set to a predetermined logic level to disconnect the memory cells from the bit lines during the sleep mode. | 11-20-2008 |
20090154274 | Memory Read Stability Using Selective Precharge - A memory device utilizes selective precharge and charge sharing to reduce a bit line voltage before accessing a bit cell. A reduction in bit line voltage is achieved by precharging different sections of the bit line to different voltages (e.g., a supply voltage and ground) and using charge sharing between these sections. Read stability improves as a result of the reduction of bit line voltage. The relative capacitance difference between bit line sections determines the bit line voltage after charge sharing. Thus, the memory device is tolerant to process or temperature variations. The bit line voltage may be controlled in design by selecting the sections that are precharged to supply voltage or ground. | 06-18-2009 |
20090160253 | System and Method of Providing Power Using Switching Circuits - In a particular illustrative embodiment, a system is disclosed that includes a first power domain that is responsive to a first power switching circuit and a second power domain that is responsive to a second power switching circuit. The system also includes a logic circuit adapted to selectively activate the first power switching circuit and the second power switching circuit. At least one of the first power switching circuit and the second power switching circuit includes a first set of transistors adapted for activation during a first power up stage and a second set of transistors adapted for activation during a second power up stage after at least one of the first set of transistors are activated. | 06-25-2009 |
20090195268 | Level Shifting Circuit and Method - In a particular embodiment, a method includes receiving an input voltage at an input to a level shifting circuit that includes voltage pull-up logic. The method includes providing an output signal from the level shifting circuit. The method also includes selectively activating the voltage pull-up logic circuit of the level shifting circuit. | 08-06-2009 |
20090231934 | Advanced Bit Line Tracking in High Performance Memory Compilers - A method accurately tracks a bit line maturing time for compiler memory. The method includes enabling a dummy word line in response to an internal clock signal. The dummy word line is enabled prior to enabling a real word line. A dummy bit line is matured in response to enabling of the dummy word line. The dummy bit line matures at a same rate that a real bit line matures. The method also includes disabling the dummy word line in response to determining a threshold voltage differential based on monitoring maturation of the dummy bit line. The real word line is enabled a predefined delay after enabling of the dummy word line. Similarly, the word line is disabled the predefined delay after disabling of the dummy word line. In response to disabling the dummy word line, a sense enable signal is generated. | 09-17-2009 |
20090285044 | TESTING A MEMORY DEVICE HAVING FIELD EFFECT TRANSISTORS SUBJECT TO THRESHOLD VOLTAGE SHIFTS CAUSED BY BIAS TEMPERATURE INSTABILITY - A supply voltage is set for a memory device at a first supply voltage level. Test data is written to the memory device at the first supply voltage level in response to setting the supply voltage. The supply voltage is decreased for the memory device to a second supply voltage level below the first supply voltage level in response to writing the test data. The test data is read from the memory device at the second supply voltage level in response to decreasing the supply voltage. The supply voltage is increased for the memory device to a third supply voltage level above the second supply voltage level in response to reading the test data. The test data is read from the memory device at the third supply voltage level in response to increasing the supply voltage. The test data written to the memory device at the first supply voltage level is compared to the test data read from the memory device at the third supply voltage level in response to reading the test data from the memory device at the third supply voltage level. | 11-19-2009 |
20100046276 | Systems and Methods for Handling Negative Bias Temperature Instability Stress in Memory Bitcells - A system and method reduce stress caused by NBTI effects by determining if a trigger event has occurred and if so inverting all input data values to the memory and all output data values from the memory during a period of time defined by the determined trigger event. In one embodiment, the trigger event is an alternate memory power-up. | 02-25-2010 |
20100046280 | SRAM Yield Enhancement by Read Margin Improvement - A sense margin is improved for a read path in a memory array. Embodiments improve the sense margin by using gates with a lower threshold voltage in a read column multiplexer. A cross coupled keeper can further improve the sense margin by increasing a voltage level on a bit line storing a high value, thereby counteracting leakage on the “high” bit line. | 02-25-2010 |
20100061161 | Self Reset Clock Buffer In Memory Devices - A memory device includes a clock buffer circuit. The clock buffer circuit includes a cross-coupled logic circuit. The cross-coupled logic circuit has at least two logic gates in which an output of at least one of the logic gates is coupled to an input of at least one of the logic gates. The cross-coupled logic circuit is coupled to an input for accepting a clock signal. The memory device also includes a clock driver operable to generate a clock signal from the output of the cross-coupled logic circuit. A feedback loop from the clock signal to the cross-coupled logic circuit controls the cross-coupled logic circuit. A buffer circuit including a tri-state inverter is coupled to the clock signal to maintain the clock signal while avoiding contention with the clock generator. The memory device is enabled by a chip select signal. | 03-11-2010 |
20100103755 | Read Assist for Memory Circuits - A method increases stability of a memory circuit by pre-charging at least one bit line of the memory circuit to a first voltage, pre-charging at least one other bit line of the memory circuit to a second voltage, and equalizing charge across the bit lines so that the bit lines are pre-charged with a third voltage. | 04-29-2010 |
20100142300 | Semiconductor Memory Device And Methods Of Performing A Stress Test On The Semiconductor Memory Device - A semiconductor memory device and method of performing a stress test on a semiconductor memory device are provided. In an example, the semiconductor memory device includes a multiplexer arrangement configured to switch a timing signal that controls an internal timing of the semiconductor memory device from an internal signal to an external signal during a stress mode, and further includes one or more word lines of the semiconductor memory device receiving a stress voltage during the stress mode, a duration of the stress mode based upon the external signal. In another example, the semiconductor memory device includes one or more word lines configured to receive a stress voltage during a stress mode, and a precharge circuit configured to provide a precharge voltage to a bit line of the semiconductor memory device during the stress mode. | 06-10-2010 |
20100146320 | Memory Access Time Measurement Using Phase Detector - Methods and systems for determining a memory access time are provided. A first phase skew is measured between a first clock signal used by a memory and a second clock signal used as a reference clock signal. Then, a second phase skew is measured between a delayed version of the first clock signal output by the memory when the memory completes a given read operation and the second clock signal. The memory access time is determined based on the first and second phase skews. | 06-10-2010 |
20100195366 | Reducing Leakage Current in a Memory Device - Memory devices and methods of reducing leakage current therein are disclosed. The memory device includes a memory core array including a plurality of bitlines, and peripheral logic configured to interface with the memory core array. The memory device further includes a footswitch configured to isolate the peripheral logic from a ground voltage, and a headswitch configured to isolate a precharge current path from the plurality of bit lines of the memory core array. Leakage current within the memory device may be reduced via the isolation provided by the footswitch and the headswitch. | 08-05-2010 |
20100226191 | Leakage Reduction in Memory Devices - A memory device includes a core array that includes memory cells. The memory device also includes a headswitch coupled to the core array and a positive supply voltage. The headswitch reduces leakage current from the core array by disconnecting the core array from the positive supply voltage. Additionally, head switches are added for pre-charge devices to further reduce leakage current. | 09-09-2010 |
20100238756 | Self Reset Clock Buffer In Memory Devices - A memory device includes a clock buffer circuit. The clock buffer circuit includes a cross-coupled logic circuit. The cross-coupled logic circuit has at least two logic gates in which an output of at least one of the logic gates is coupled to an input of at least one of the logic gates. The cross-coupled logic circuit is coupled to an input for accepting a clock signal. The memory device also includes a clock driver operable to generate a clock signal from the output of the cross-coupled logic circuit. A feedback loop from the clock signal to the cross-coupled logic circuit controls the cross-coupled logic circuit. A buffer circuit including a tri-state inverter is coupled to the clock signal to maintain the clock signal while avoiding contention with the clock generator. The memory device is enabled by a chip select signal. | 09-23-2010 |
20100250865 | Self-Timing For A Multi-Ported Memory System - Multi-ported memory systems (e.g., register files) employ self-timing for operational synchronization. Thus, rather than using a reference clock duty cycle for operational synchronization, as in conventional multi-ported register files, embodiments of the present disclosure employ self-timing for such operational synchronization. According to certain embodiments, self-timing is employed to synchronize all the internal events within the memory so that all the events are spaced in time for appropriate synchronization. For instance, the completion of one event leads to triggering another event, the completion of which leads to triggering another event, and so on. Thus, in one embodiment, the self-timing is achieved by referencing the operational events with the memory (or register file) to each other, rather than to a reference clock duty cycle. | 09-30-2010 |
20110235449 | Dual Sensing Current Latched Sense Amplifier - A sense amplifier and method thereof are provided. The sense amplifier includes first and second transistors coupled to first and second bit lines, respectively. The first and second transistors are configured to connect the first and second bit lines to a differential amplifier during a first state (e.g., when a differential voltage is present on the first and second bit lines and prior to a sense signal transition) and to isolate the first and second bit lines from the differential amplifier during a second state (e.g., after the sense signal transition). The sense amplifier further includes a third transistor configured to deactivate the differential amplifier during the first state and configured to activate the differential amplifier during the second state. | 09-29-2011 |
20120068774 | Amplitude Control for Oscillator - An amplitude control circuit includes a pair of peak detectors. The pair of peak detectors are responsive to a voltage reference generator. The amplitude control circuit is configured to be responsive to an oscillating signal of a crystal oscillator and configured to generate a control signal to control an amplitude of the oscillating signal. | 03-22-2012 |
20120072793 | Registers with Full Scan Capability - A scan test of a first latch and a second latch couples a given scan value to the input of the first latch, to switch the first latch to a state corresponding to the scan value, uncouples the scan value from the first latch to latch the first latch at that state, couples the output of the first latch while latched at that state to the input of the second latch to switch the second latch to that state, and uncoupling the output of the first latch from the input of the second latch to latch the second latch at that state. | 03-22-2012 |
20120082174 | Sense Amplifier with Selectively Powered Inverter - A sense amplifier includes a first inverter responsive to a first output of a latch. The first inverter is powered by a sense enable signal. The sense amplifier also includes a second inverter responsive to a second output of the latch. The second inverter is also powered by the sense enable signal. | 04-05-2012 |
20140266343 | AREA-EFFICIENT PLL WITH A LOW-NOISE LOW-POWER LOOP FILTER - Techniques for reducing noise and power consumption in a loop filter for a phase-locked loop (PLL) are described herein. In one embodiment, a loop filter for a PLL comprises a first proportional capacitor, a second proportional capacitor, an active device, and a plurality of switches. The plurality of switches are configured to alternately couple the first proportional capacitor and the second proportional capacitor to a first charge pump, to alternately couple noise from the active device to the first proportional capacitor and the second proportional capacitor, and to alternately couple the first proportional capacitor and the second proportional capacitor into a feedback circuit, wherein the feedback circuit produces an output voltage of the loop filter. | 09-18-2014 |
20140321227 | FREQUENCY POWER MANAGER - A method and an apparatus are provided. The apparatus is a hardware module that controls a power mode of a plurality of modules. The apparatus receives an indication of a desired operational frequency. Based on the received indication, the apparatus determines to switch from a first power mode associated with a first set of modules to a second power mode corresponding to the desired operational frequency and associated with a second set of modules. The apparatus enables modules in the second set of modules that are unassociated with the first power mode, stops traffic through the plurality of modules upon expiration of a time period after enabling the modules in the second set of modules that are unassociated with the first power mode, routes traffic through the second set of modules, and disables modules in the first set of modules that are unassociated with the second power mode. | 10-30-2014 |