Texas Instruments Corporation

International Business Machines Corporation

Freescale Semiconductor,inc.

Tam Minh Tran

George B Jamison

David Barry Scott

Hugh Thomas Mair

Xiaowei Deng

Bryan David Sheffield

Shyh-Horng Yang

Bikas Maiti

David J Toops

Lawrence N Herr

Mehran Moghaddam

Luan A Dang

Vikas K Agrawal

Joshua Hansen

Scott A Taylor

Rajesh R Kini

John Frederick Boylan

Raj K Raheja

Eduardo Torres

Dehua Huang

Jingjing Zhao

Shuichan Xu

Heather Raymon

Robert Hubbard

Jim Leisten

Sogole Bahmanyar

Brandon Jeffy

Matthew Alexander

Kimberly Schwarz

Marianne Sloss

An integrated circuit comprises a plurality of memory cells and an array supply voltage control circuit. The plurality of memory cells are organized in rows and columns. A row comprises a word line and all of the memory cells coupled to the word line. A column comprises a bit line pair and all of the memory cells coupled to the bit line pair. The array supply voltage control circuit is coupled to the plurality of memory cells. The array supply voltage control circuit is for receiving a power supply voltage and for providing a reduced power supply voltage to memory cells of a selected column during a write operation in response to a voltage differential on the bit line pair of the selected column.

Integrated circuit having an array supply voltage control circuit

A low power E-fuse repair methodology substantially removes system latency during memory and/or E-fuse farm module power-down in a device that employs E-fuse farm technology. The method maintains power to the repair registers and minimal control logic in the memories, while all other circuitry can be either placed in a low power data retention mode, or completely powered off. There is no need to rescan the repair data from the E-fuse farm after one or more memories are powered back up. This provides dynamic power savings since there is no longer any need to idle the system to reload repair data. Since the E-fuse farm can be powered down after initial system power-up and repair data is loaded into the memories, there is also a significant leakage power savings.

Low-power SRAM E-fuse repair methodology

An embodiment of a ultra low-power data retention latch circuit involves a slave latch SL that concurrently latches the same data that is loaded into a main circuit (such as a main latch ML) during normal operation. When the circuit enters a low power (data retention) mode, power (VCC) to the main latch ML is removed and the slave latch SL retains the most recent data (retained data SA, SA-). When power is being restored to the main latch ML, the slave latch's retained data SA, SA- is quickly restored to the main latch ML through what constitute Set and Reset inputs SAR, SAR- of the ML. This arrangement ensures that data restoration is much quicker than conventional arrangements that require the output data path DATA- to be stabilized before power is re-applied to the main latch. Further, there is no need to wait for power to the ML to be stable before restoring data from the SL to the ML, providing an increase in data restoration speed over conventional data retention latches. Using retained data SA, SA- (as mirrored in SAR, SAR-) to control the Set and Reset inputs prevents data contention in the main latch ML. Moreover, compared to known arrangements, the arrangement provides minimal loading on the DATA, DATA- output paths (driving only N, N), thus not compromising speed on the data path (DATAIN . . . DATA/DATA-) through the main latch during normal operation.

Ultra low-power data retention latch

The method for powering down a circuit for a data retention mode includes: changing a supply voltage node from an active power voltage level to an inactive power level; coupling a source of a P channel device to the supply voltage node; providing a retaining power supply voltage level to a back gate of the P channel device; changing a drain voltage of the P channel device to a reference voltage level, wherein the reference voltage level is different from the retaining power supply voltage level; and changing a gate voltage of the P channel device to the reference voltage level.

Leakage current reduction method

According to one embodiment of the invention, a memory circuit operable to assume a standby mode is provided. A memory circuit includes a transistor comprising a gate and a bulk. The bulk is at a retention voltage level. The memory circuit also includes a first node and a second node that are coupled to each other by the transistor. The first node is operable to assume a higher voltage level than the second node in response to an initiation of the standby mode. The memory circuit also includes a third node coupled to the gate of the transistor. The third node is operable to assume a voltage approximately equal to the retention voltage in response to an initiation of the standby mode. The transistor is operable to reduce any direct current flow between the first node and the second node in response to a rise in voltage at the third node to a voltage approximately equal to the retention voltage.

Method and system for power conservation in memory devices

Two separate dummy wordlines, a read dummy wordline and a write dummy wordline, are implemented within a memory array to provide for higher frequency operation of read and write cycles within the memory array. The two dummy wordlines are utilized to activate and deactivate the wordline enable signal for the read and write portions of an access. Such an access can be a read/swap cycle.

Dummy wordline circuitry

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Austin, TX, United States of America

Tam Minh Tran