Programmable Microelectronics Corporation

Nexflash Technologies, Inc.

Chingis Technology Corporation

Ker-Ching Liu

Hsi-Hsien Hung

Kyoung-Chon Jin

Shiou-Yu Alex Wang

Fungioon Park

A memory apparatus includes a main memory, a redundant memory, and a substitution control unit. The main memory is configured to receive a read address and output a main data word comprising a plurality of main data sub-words where the read address includes a first portion and a second portion. The redundant memory is configured to receive the read address first portion and output a redundant data sub-word. The substitution control unit includes a substitution control word memory configured to store a plurality of substitution control words and configured to receive the read address first portion and assert a substitution control word including a substitution address second portion. The read address first portion and substitution address second portion form a substitution address. The substitution control unit asserts a substitution control signal when there is a match between the read address and the substitution address.

Redundant memory content substitution apparatus and method

A memory cell array is physically divided into an even number of sectors, with each pair of sectors sharing read circuitry. The outputs of the shared read circuitry are commonly connected to form data lines spanning the height of the array, which are input to global sense amplifiers. A two-stage sensing scheme is employed, with first stage and global sense amplifiers. The driving capability of the first stage sense amplifier can be used to decrease the time to charge or discharge the data lines, which reduces the total signal development time and consequently improves read performance. Granularity of the array can be adjusted by dividing groups and sub-groups of memory cells within a sector accordingly. In a read operation, the bit line in the opposite sector at the same column location is used as reference bit line, which greatly improves matching of bit line loading for the sensing.

Non-volatile memory architecture to improve read performance

A sub-bit line architecture for non-volatile memory devices. Four sub-bit lines are coupled to each main bit line. The sub-bit lines are approximately one half the length of the main bit lines in each sector. This sub-bit line length provides low parasitic capacitance and high signal integrity. Each sub-bit line is coupled to a main bit line through a select transistor. A column latch is coupled to each main bit line to provide program data. Data is programmed to the memory array in a page program mode. In page program mode, the selected sub-bit line applies a programming voltage to the memory cell transistor drain terminals. The drain voltage is applied to all of the memory cell transistor drains coupled to the selected sub-bit line. Since the sub-bit lines are only half the length of the main bit lines in each sector, the number of memory cell transistors coupled to each sub-bit line is about half the number coupled to sub-bit lines that are the length of the main bit line. As a result, the number of times memory cell transistors are disturbed due to increases in drain voltage caused by the sub-bit line being selected is reduced. A further advantage of the present invention is that program disturb is reduced.

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Palo Alto, CA, United States of America

Ker-Ching Liu