Sandisk Technologies Inc.

Western Digital Technologies, Inc.

Sandisk Corporation

Cynthia Hsu

Yingda Dong

Ken Oowada

Masaaki Higashitani

Deepanshu Dutta

Man Lung Mui

Henry Chin

Yan Li

Huai-Yuan Tseng

Chris Avila

Gautam Ashok Dusija

Changyuan Chen

Tai-Yuan Tseng

YenLung Li

Dana Lee

Toru Miwa

Anubhav Khandelwal

Deepak Raghu

Farookh Moogat

Navneeth Kankani

Arash Hazeghi

Manabu Sakai

Lei Lin

Kwang Ho Kim

Zhuojie Li

Ching-Huang Lu

Murong Lang

Seungpil Lee

Abhijeet Manohar

Daniel Edward Tuers

Raul Adrian Cernea

Ravi J Kumar

Eran Erez

Qui V Nguyen

Pitamber Shukla

Fanglin Zhang

Xue Bai Pitner

Jong Hak Yuh

Yen-Lung Li

Min Peng

Yee Lih Koh

Yingqa Dong

A data storage system includes a storage medium including a plurality of strings of single-level cell (SLC) memory cells connected to a plurality of word lines; and a storage controller in communication with the storage medium, the storage controller including write circuitry configured to write data to the storage medium by: selecting a first word line of the plurality of word lines, the first word line being connected to a first plurality of strings; consecutively programming a first group of memory cells of the first plurality of strings connected to the first word line; and subsequent to programming the first group of memory cells, consecutively verifying respective programming results of the first group of memory cells.

Program with consecutive verifies for non-volatile memory

Aspects of a storage device are provided that reduce calculations for identifying physical locations of data during a read operation. In one aspect, a memory device includes one or more memory arrays. Each array includes multiple chunks of memory. The device includes a first set of registers for storing prefixed starting addresses for each array. The device further includes control logic that may identify bad physical address in each array. For each successive chunk in each array and based on the prefixed starting address and the bad physical address locations, the device may determine a pointer to a starting physical address for the chunk. The pointer may be stored in a second set of registers for use in register read operations.

Circuit to reduce gating overall system performance

A storage device is disclosed herein. The storage device comprises a block including a plurality of memory cells and a circuit coupled to the plurality of memory cells of the block. The circuit is configured to program memory cells of a plurality of strings of a word line of the block and verify, for a plurality of sets of the memory cells, a data state of a set of the memory cells, where each set of the plurality of sets of the memory cells includes a memory cell from each string of the plurality of strings of the word line. Further, the circuit is configured to determine a number of sets of the plurality of memory cell sets that are verified to be in a first data state and determine, based on the number of sets, whether the block is faulty.

Programming techniques including an all string verify mode for single-level cells of a memory device

An apparatus is provided that includes a plurality of memory cells, a programming circuit configured to apply a plurality of programming pulses to the memory cells, and a scanning circuit configured to repeatedly switch between performing an n-state bitscan after each programming pulse until first predetermined criteria are satisfied, and performing an m-state bitscan after each programming pulse until second predetermined criteria are satisfied, where m&#x3e;n, and n&#x3e;0.

Dynamic bit-scan techniques for memory device programming

Non-volatile storage systems and method of operating non-volatile storage systems are disclosed. A crept up voltage on a memory cell control gate adjacent to a select gate is prevented, reduced, and/or discharged. In some aspects, the crept up voltage is not allowed to happen on the memory cell next to the select gate after a sensing operation. In some aspects, the voltage may creep up on the memory cell control gate after a sensing operation, but it is discharged. Reducing and/or preventing the crept up voltage may reduce the electric field between the dummy memory cell and select gate transistor. This may prevent, or at least reduce, changes in threshold voltage of the select gate transistor. Additional problems may also be solved by a reduction of the crept up voltage on the dummy memory cell control gates.

Non-volatile memory with methods to reduce creep-up field between dummy control gate and select gate

Systems and methods for improving the reliability of data stored in memory cells are described. To mitigate the effects of trapped electrons after one or more programming pulses have been applied to memory cells, a delay between the one or more programming pulses and subsequent program verify pulses may be set based on a chip temperature, the number of the one or more programming pulses that were applied to the memory cells, and/or the programming voltage that was applied to the memory cells during the one or more programming pulses. To mitigate the effects of residual electrons after one or more program verify pulses have been applied to memory cells, a delay between the one or more program verify pulses and subsequent programming pulses may be set based on a chip temperature and/or the programming voltage to be applied to the memory cells during the subsequent programming pulses.

Multi-die programming with die-jumping induced periodic delays

A storage module and method for scheduling memory operations for peak-power management and balancing are provided. In one embodiment, a storage module maintains a count of time slots over a period of time. The period of time corresponds to an amount of time between periodic power peaks of a memory operation. For each time slot, the storage module determines whether to commence a memory operation on one or more of the plurality of memory dies based on whether a power peak generated in the time slot by the memory operation would exceed a power threshold allowed for the time slot. Other embodiments are provided.

Storage module and method for scheduling memory operations for peak-power management and balancing

Techniques are presented to reduce the amount of read disturb on partially written blocks of NAND type non-volatile memory, both for when determining the last written word line in a block and also for data read. In both cases, non-selected word lines that are unwritten or, in the case of finding the last written word line, may be unwritten are biased with a lower read-pass voltage then is typically used. The result of such reads can also be applied to an algorithm for finding the last written word by skipping a varying number of word lines. Performance in a last written page determination can also be improved by use of shorter bit line settling times than for a standard read.

Techniques for reducing read disturb in partially written blocks of non-volatile memory

Apparatuses, systems, and methods are disclosed for accessing non-volatile memory. A bit line is coupled to storage cells for a non-volatile memory element. A sense amplifier is coupled to a bit line. A sense amplifier includes a sense circuit and a bias circuit. A sense circuit senses an electrical property of a bit line for reading data from one or more storage cells, and a bias circuit applies a bias voltage to the bit line for writing data to one or more storage cells. A bias circuit and a sense circuit comprise separate parallel electrical paths within a sense amplifier.

Sense amplifier with program biasing and fast sensing

Techniques are provided for optimizing the programming of memory cells by obtaining a metric which indicates a program or erase rate of the memory cells. In one approach, a count of pulses used to program the cells to different verify levels of respective data states is stored. A slope of a straight line fit of data points is then obtained. Each data point can include one of the verify levels and a corresponding one of the counts. An optimal step size is determined based on the slope. The counts may exclude one or more initial program voltages while the cells are programmed sufficiently to allow faster and slower cells to be distinguished, e.g., in a natural threshold voltage distribution. An erase depth can also be adjusted. The cells can be programmed in a separate evaluation or during programming of user data.

Adaptive determination of program parameter using program of erase rate

Techniques are provided for efficiently performing programming operations in a memory device. In particular, power consumption is reduced in sensing circuitry by avoiding pre-charging of bit lines for certain memory cells at certain times during a programming operation. One approach uses knowledge of the different phases of a programming operation to reduce the number of unnecessary bit line pre-charges. For example, during the lower program loop numbers of a programming operation, bit line pre-charging may occur for lower data states but not for higher data states. Similarly, during the higher program loop numbers, bit line pre-charging may occur for higher data states but not for lower data states. In another approach, which may or may not incorporate knowledge of the different phases of a programming operation, the setting of the bit line pre-charge can be updated at least once after it is initially set in the verify portion.

Adaptive selective bit line pre-charge for current savings and fast programming

A non-volatile memory system mitigates the effects of open block reading by analyzing the un-programmed region of a block before programming to determine a potential for read disturbance. The system may determine a read count value associated with open block reading of the memory block and/or perform partial block erase verification. To mitigate the effects of open block read disturbance, the system performs partial block erase for the un-programmed region of the memory block and/or limits programming in the un-programmed region.

Partial block erase for open block reading in non-volatile memory

A non-volatile memory includes an data latch structure for programming bit lines using at least three programming levels. A sense amplifier includes a first data latch for controlling the voltage of a corresponding bit line, and a second static data latch with scan circuitry for performing logic operations on the program data and sense results. The sense amplifier scans low verify sense results with program data to generate reduced programming data. The reduced programming data is transferred out of the first data latch after sensing for all states and the program data is scanned to generate program enable/inhibit data which is stored in the first data latch. After setting the bit line to a program inhibit or program enable level, the reduced programming data is transferred back to the first data latch. The bit lines for reduced programming are then adjusted to the reduced programming level.

Sense amplifier with efficient use of data latches

Growing community of inventors

Milpitas, CA, United States of America

Cynthia Hsu