Silicon Storage Technology, Inc.

Xiaozhou Qian

Yao Zhou

Kai Man Yue

Xiao Yan Pi

Vipin Tiwari

Guangming Lin

Ning Bai

Bin Sheng

Yaohua Zhu

Nhan Do

Jinho Kim

Claire Zhu

Zhenlin Ding

Ryan Mei

Hieu Van Tran

Tao Wang

Xian Liu

Alexander Kotov

Viktor Markov

Yuri Tkachev

Qing Rao

Jong-Won Yoo

Jiaxu Peng

Guang Yan Luo

Li Fang Bian

Lisa Bian

Lu Guo

Kaiman Yue

Various embodiments are disclosed for performing address fault detection in a memory system using a hierarchical ROM encoding system. In one embodiment, a hierarchical ROM encoding system comprises two levels of ROM encoders that are used to detect an address fault. In another embodiment, a hierarchical ROM encoding system comprises three levels of ROM encoders that are used to detect an address fault.

Hierarchical ROM encoder system for performing address fault detection in a memory system

The present embodiments relate to systems and methods for implementing wear leveling in a flash memory device that emulates an EEPROM. The embodiments utilize an index array, which stores an index word for each logical address in the emulated EEPROM. The embodiments comprise a system and method for receiving an erase command and a logical address, the logical address corresponding to a sector of physical words of non-volatile memory cells in an array of non-volatile memory cells, the sector comprising a first physical word, a last physical word, and one or more physical words between the first physical word and the last physical word; when a current word, identified by an index bit, is the last physical word in the sector, erasing the sector; and when the current word is not the last physical word in the sector, changing a next index bit.

Wear leveling in EEPROM emulator formed of flash memory cells

The present invention relates to systems and methods for implementing wear leveling in a flash memory device that emulates an EEPROM. The embodiments utilize an index array, which stores an index word for each logical address in the emulated EEPROM. Each bit in each index word is associated with a physical address for a physical word in the emulated EEPROM, and the index word keeps track of which physical word is the current word for a particular logical address. The use of the index word enables a wear leveling algorithm that allows for a programming command to a logical address to result in: (i) skipping the programming operation if the data stored in the current word does not contain a '1' that corresponds to a '0' in the data to be stored, (ii) reprogramming one or more bits of the current word in certain situations, or (iii) shifting to and programming the next physical word in certain situations.

A memory device that includes a memory array having pluralities of non-volatile memory cells, a plurality of index memory cells each associated with a different one of the pluralities of the non-volatile memory cells, and a controller. The controller is configured to erase the pluralities of non-volatile memory cells, set each of the index memory cells to a first state, and program first data into the memory array by reading the plurality of index memory cells and determining that a first one of the index memory cells is in the first state, programming the first data into the plurality of the non-volatile memory cells associated with the first one of the index memory cells, and setting the first one of the index memory cells to a second state different from the first state.

Non-volatile memory device with stored index information

An improved level shifter is disclosed. The level shifter is able to achieve a switching time below 1 ns using a relatively low voltage for VDDL, such as 0.75 V. The improved level shifter comprises a coupling stage and a level-switching stage. A related method of level shifting is also disclosed.

Low voltage level shifter for integrated circuit

An improved level shifter for use in integrated circuits is disclosed. The level shifter is able to achieve a switching time below 1 ns while still using the core power supply voltages, VDDL and VDDH, used in the prior art. The improved level shifter comprises a coupling stage and a level-switching stage.

Level shifter for integrated circuit

A method and apparatus are disclosed for reducing the coupling that otherwise can arise between word lines and control gate lines in a flash memory system due to parasitic capacitance and parasitic resistance. The flash memory system comprises an array of flash memory cells organized into rows and columns, where each row is coupled to a word line and a control gate line.

Method and apparatus for reducing coupling between word lines and control gate lines in a flash memory system

Multiple embodiments of a low power sense amplifier for use in a flash memory system are disclosed. In some embodiments, the loading on a sense amplifier can be adjusted by selectively attaching one or more bit lines to the sense amplifier, where the one or more bit lines each is coupled to an extraneous memory cell.

Low power sense amplifier for a flash memory system

The present invention relates to an improved sense amplifier for reading values in flash memory cells in an array. In one embodiment, a sense amplifier comprises an improved pre-charge circuit for pre-charging a bit line during a pre-charge period to increase the speed of read operations. In another embodiment, a sense amplifier comprises simplified address decoding circuitry to increase the speed of read operations.

Sense amplifier with bit line pre-charge circuit for reading flash memory cells in an array

The disclosed embodiments comprise a flash memory device and a method of programming the device in a way that reduces degradation of the device compared to prior art methods.

System and method for programming split-gate, non-volatile memory cells

An improved sensing circuit is disclosed that utilizes a bit line in an unused memory array to provide reference values to compare against selected cells in another memory array. A circuit that can perform a self-test for identifying bit lines with leakage currents about an acceptable threshold also is disclosed.

High speed and low power sense amplifier

A system and method to inhibit the erasing of a portion of a sector of split gate flash memory cells while allowing the remainder of the sector to be erased is disclosed. The inhibiting is controlled by control logic that applies one or more bias voltages to the portion of the sector whose erasure is to be inhibited.

System and method to inhibit erasing of portion of sector of split gate flash memory cells

A self-timer for a sense amplifier in a memory device is disclosed.

Self-timer for sense amplifier in memory device

A memory device that includes a plurality of ROM cells each having spaced apart source and drain regions formed in a substrate with a channel region therebetween, a first gate disposed over and insulated from a first portion of the channel region, a second gate disposed over and insulated from a second portion of the channel region, and a conductive line extending over the plurality of ROM cells. The conductive line is electrically coupled to the drain regions of a first subgroup of the ROM cells, and is not electrically coupled to the drain regions of a second subgroup of the ROM cells. Alternately, a first subgroup of the ROM cells each includes a higher voltage threshold implant region in the channel region, whereas a second subgroup of the ROM cells each lack any higher voltage threshold implant region in the channel region.

Array of non-volatile memory cells with ROM cells

The invention comprises a non-volatile memory device with a sensing amplifier that includes a current mirror comprising a pair of resistors.

Growing community of inventors

Shanghai, China

Xiaozhou Qian