Oracle International Corporation

Oracle America, Inc.

Sun Microsystems, Inc.

Jungyong Lee

Heechoul Park

Hoyeol Cho

Singrong Li

Jinho Kwack

Tsunghsun Hsieh

Song C Kim

Myung Gyoo Won

Peter Normand Labrecque

Xiaozhen Guo

Chienan Lai

Embodiments include systems and methods for improving column selection functionality of memory circuits. Embodiments operate in context of memory bitcells having additional series pass gates (e.g., junction sharing transistors) coupled with a column select signal to form an integrated column select port. Such a column select port can provide each bitcell with column select functionality in a manner that has improved area and power performance over some conventional (added NOR or other logic) approaches. However, the added column select port can still tend to add area, add column select load, and degrade writability (e.g., due to certain charge-sharing effects). Some embodiments are described herein for addressing the area and column select load by sharing certain intermediate nodes among multiple, adjacent bitcells. Other embodiments can include additional ground-connected transistors in a manner that improves writability (e.g., and read noise margin) of the bitcell.

Memory bitcell with column select

Embodiments include systems and methods for providing robust clock-skew-tolerant memory updating in high-speed memory circuits. For example, in each memory update interval, update of a pre-memory with un-validated update data begins when a potential match is detected between a tag memory and a key (whether according to a base clock or a delayed clock); but the update data is not considered valid (nor is it written out as such) until a determination is made according to the delayed clock. The un-validated update data can be written out from the pre-memory as validated update data for the memory update interval upon detection of a data valid indication generated from the delayed hit indication.

Clock-skew-tolerant memory updating

A memory array for process variation tolerant bypass operation. The memory array may utilize normal read operation data path of a memory I/O module. Accordingly, the speed at which the bypass operation may be executed may be increased. Furthermore, a potential for false read operations introduced by the utilization of the normal read operation data path of the memory I/O module may be reduced using a protect mechanism operable to block the output of false reads from the memory array.

High speed read access memory array with variation tolerant bypass scheme with protection circuit

A system for efficient execution of a read or a write is described. The system includes a memory array including a way. The system further includes a read and compare circuit. The read and compare circuit compares data stored within lower address memory cells of the way with information received from a storage device to generate a result of comparison. Moreover, the read and compare circuit compares data stored within higher address memory cells of the way with the information to generate a result of comparison. The system further includes a merge and multiplex circuit coupled to the read and compare circuit. The merge and multiplex circuit merges the result of comparison generated based on the comparison with the lower address memory cells and the result of comparison generated based on the comparison with the higher address memory cells to create a merged outcome of comparison.

Circuits and methods for efficient execution of a read or a write operation

Dynamic power consumption is reduced by clock gating registers that synchronize memory input signals in an embedded memory array. Where a memory enable signal associated with a memory interface input signal does not meet setup timing for clock gating input registers of the memory interface signal, a clock gate enable signal may be generated prior to evaluation of the memory enable signal. The clock gate enable signal includes all functions of the memory enable signal and additional conditions because it is generated prior to evaluation of conditions on which the memory enable signal may depend. Pre-evaluated clock gate enable signals may be generated within a processor core and used to clock gate read address registers, write address registers, data input registers, and/or CAM reference address registers of an embedded memory array.

Memory array clock gating scheme

Embodiments include systems and methods for faster memory read-out using a combined read-select circuit. A novel read-select circuit is described, which, when enabled for reading, concurrently reads its respective input line and selects its value for read-out by the circuit. This can reduce delays and unnecessary toggling resulting from separate read and select circuits. Some implementations also include a multi-global-line architecture that can reduce the number of read stages in the memory read-out circuitry, thereby further reducing read-out delays. Accordingly, embodiments can be faster and more efficient than many traditional implementations without relying on an increase in power consumption or clock speed.

Fast memory read-out

A process variation tolerant collision detection apparatus for use in detecting collisions in a multibank memory. The apparatus may receive a plurality of memory commands for execution at the multibank memory. The plurality of memory commands may be compared by an index address comparator and a bank address comparator to generate an index match signal and a bank match signal. The index match signal and the bank match signal may be analyzed by a timing correction module such that errors associated with process variation of the signals used in the system may be eliminated. Accordingly, a corrected index match signal and a corrected bank match signal may be provided to a collision detection circuit to determine whether a collision exits.

Process variation tolerant bank collision detection circuit

A memory device that includes multiple blocks of static random access memory (SRAM), which each have a standby mode and an active operating mode, is described. During the active operating mode, a selection circuit couples a higher voltage from a first power-signal line and a power-supply circuit to a given block of SRAM, and during the standby mode the selection circuit couples a lower voltage from a second power-signal line to the given block of SRAM. Note that a regulator circuit regulates the lower voltage on the second power-signal line by selectively opening or closing a first switch between the first power-signal line and the second power-signal line. Furthermore, a recycling circuit selectively opens a second switch between the first switch and the first power-signal line when the block of SRAM transitions from the active operating mode to the standby mode, thereby transferring charge from the block of SRAM to other blocks of SRAM.

Dynamically controlled voltage regulator for a memory

A push-pull voltage regulator configured to selectively provide power to used portions of a memory array is presented. The push-pull voltage regulator includes a voltage-up regulator, which provides a reference voltage to an SRAM array, and a voltage-down regulator, which controls removal of excess charge from the SRAM array. The voltage-down regulator consists of a plurality of amplifier stages with a plurality of inputs, a plurality of inverters, a gain amplifier, a biasing transistor, and a NMOS drainage transistor. The gate terminal of the NMOS drainage transistor is coupled to an output of the voltage-down regulator. A first output terminal of the NMOS drainage transistor coupled to an output node of the push-pull voltage regulator and a second output terminal of the NMOS drainage transistor coupled to ground. When activated, the NMOS drainage transistor transfers excess charge from the SRAM array to ground.

Voltage regulator for write/read assist circuit

A phase shift driver for phase shifting an input clock signal at a first phase to generate an output signal at a second phase without missing subsequent input signals. Input logic circuitry of the phase shift driver may receive an input signal at a first phase. Output logic circuitry of the phase shift driver may generate an output signal at a second phase relative to the input signal. The output signal may be a phase-shifted version of the input signal. A reset control circuit may receive a feedback signal from the output logic circuitry and an intermediate signal from the input logic circuitry and generate a reset signal based on the received feedback and intermediate signals. The reset control circuit may control a pulse width of the reset signal to reset the input logic circuitry within a period of time before the input logic circuitry receives a subsequent input signal.

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San Jose, CA, United States of America

Jungyong Lee