Macronix International Co., Ltd.

Integrated Memory Technologies, Inc.

Integrated Silicon Solution Incorporated

Other

Winbond Electronics Corporation

Macronix Internatioal, Ltd.

Tien-Ler Lin

Tom D Yiu

Fuchia Shone

Ray L Wan

Ling Chen

Ling-Wen Hsiao

Liang Chao

Cheng-Chung Tsao

Kong-Mou Liou

Chun-Hsiung Hung

Albert Wu

Ray-Lin Wan

Gilbert Sung

Kota Soejima

Hui W Chen

Jun Takahashi

Eungjoon Park

Yao-Wu Cheng

Ching-Shi Jenq

Ting-Chung Hu

Kwangho Kim

Satoshi Matsubara

Method and apparatus for memory device testing at a higher clock rate than the clock rate provided by a memory tester. The method includes providing a memory tester capable of generating a first clock signal characterized by a first clock frequency, and applying the first clock signal to the memory device. The method also includes receiving a command for activating a high-clock-frequency test mode. The method generates a second clock signal in the memory device in response to the first clock signal. The second clock signal is characterized by a second clock frequency which is higher than the first clock frequency. The method then tests the memory device at the second clock frequency. In a specific embodiment, the method is applied to a serial flash memory device. The invention can also be applied to testing and operating other memory devices or systems that include synchronized circuits.

Clock frequency doubler method and apparatus for serial flash testing

An integrated circuit memory device has an array of non-floating gate non-volatile flash cells arranged in a NOR configuration. The device further has page buffers and control circuits to operate the array in either a NAND mode of operation or a NOR mode of operation. Finally, the array is partitionable by a user into two partitions such that one partition operates only in the NAND mode while the other partition operates only in a NOR mode.

Combination NAND-NOR memory device

A nonvolatile semiconductor memory includes a plurality of memory cells arranged in columns and rows, a plurality of word lines, a plurality of bit lines, a plurality of output buffers, and a plurality of page buffers grouped in a plurality of sub-pages. Each page buffer is connected to corresponding bit lines through a first column decoder circuit and connected to one corresponding output buffer through a second column decoder circuit. This construction allows the peripheral control circuits to clock out data stored in page buffers of a first sub-page into output buffers while latching bit line data into page buffers of a second sub-page. Therefore, this architecture is able to perform read and update the page buffer data of different sub-pages simultaneously. Two sets of address registers are used to store the starting and the end address for programming. During programming, only sub-pages located between the starting and end address will be programmed successively. This sub-page programming technique greatly reduces the disturbance and programming time.

Integrated circuit memory device having interleaved read and program capabilities and methods of operating same

An integrated circuit chip suitable for use in either a single chip packaged configuration or a multi-chip packaged configuration is disclosed. The chip has a conventional memory circuit portion and a control circuit portion. In operation as a single chip packaged configuration, the control circuit portion is inactive. In a multi-chip packaged configuration, the control circuit serves to prolong the activation of the currently addressed memory chip, while delaying the activation of the memory chip which is to be addressed in the next memory address cycle.

Integrated circuit memory chip for use in single or multi-chip packaging

A charge pump circuit which generates an output voltage at a selected level, but variations in the current supplied to the charge pump are limited, and variations in the output current generated by the charge pump are limited. The charge pump circuit is coupled to a power supply which has a supply voltage which varies over a specified range. It includes a first charge pump that generates a reference voltage higher than the supply voltage in response to the supply voltage. A circuit, coupled to the first charge pump and responsive to the reference voltage generates a regulated supply voltage. A second charge pump generates a controlled output voltage in response to the regulated supply voltage. The regulated supply voltage is used by pump clock drivers and as a pump reference supply for the second charge pump.

Regulated reference voltage circuit for flash memory device and other integrated circuit applications

A circuit for speeding up the pre-programming of floating gate storage transistors such as FLASH EPROMS, and particularly speeding up the pre-programming of a block or array of floating gate storage transistors includes a controllable voltage source that supplies gate programming potential across the control gate and source of the FLASH EPROM transistor cells to be programmed. A control circuit is provided that controls the voltage source to vary the gate programming potential during a programming interval as a function of time in order to decrease the time required for a given amount of charge movement to program the selected floating gate transistors. The wordline voltages are varied, while the source voltage is held constant. By starting at a lower wordline voltage, and increasing during the programming interval to a high wordline voltage, the programming speed is increased, and the high final turn-on threshold voltage for the programmed floating gate storage transistors is achieved. In addition, in order to speed up pre-programming, a programming potential is applied to four wordlines in parallel during a single programming interval. Further, the load on cells being programmed is adjusted to improve programming speed.

Fast flash EPROM programming and pre-programming circuit design

Non-volatile memory device for fault tolerant data

An integrated circuit comprises a functional module such as a FLASH memory with automatic program and erase circuits, test circuitry coupled with the functional module which executes a test of the functional module and generates status information as a result of the test, and non-volatile status write circuitry coupled with the test circuitry on the chip. A circuit in the non-volatile status write circuitry is responsive to the test of the functional circuitry to write the status information to the non-volatile memory. A port is provided on the integrated circuit coupled to the non-volatile memory through which the status information stored in the non-volatile memory is accessible in a test read mode to external devices. In a FLASH EPROM embodiment, the IC includes an array of FLASH EPROM memory cells and a port through which data in the array is accessible by external devices. A test set of FLASH EPROM memory cells is provided in the array. Program and erase circuitry, coupled to the array, has a test mode to exercise the program and erase circuitry to generate status information indicating results of the test and test read mode to read out the status information. Non-volatile status write circuitry, is coupled to the program and erase circuitry and the test set, and writes the status information to the test set. The program and erase circuits include retry counts with programmable thresholds for reducing the test times of the devices.

Automatic test circuitry with non-volatile status write

Advanced program verify for page mode flash memory

An improved contactless EPROM array, EPROM cell design, and method for fabricating the same is based on a unique drain-source-drain configuration, in which a single source diffusion is shared by two columns of transistors. An elongated first drain diffusion region, an elongated source diffusion region, and an elongated second drain diffusion region, are formed in a semi-conductor substrate along essentially parallel lines. Field oxide regions are grown on opposite sides of the first and second drain diffusion regions. Floating gates and control gate wordlines are formed orthogonal to the drain-source-drain structure to establish two columns of storage cells having a shared source region. The shared source region is coupled through a bottom block select transistor to a virtual ground terminal. Each drain diffusion region is-coupled through a top block select transistor to global bitline. The cell structure uses two metal global bitlines which extend essentially parallel to the drain, source and drain diffusion regions, and a virtual ground conductor which couples a plurality of columns of transistors to a virtual ground terminal through a horizontal conductor, such as a buried diffusion line.

Non-volatile memory cell and array architecture

Technique for reconfiguring a high density memory

Growing community of inventors

Cupertino, CA, United States of America

Tien-Ler Lin