Winbond Electronics Corporation

Nexflash Technologies, Inc.

Kwangho Kim

Eungjoon Park

Hui W Chen

Tien-Ler Lin

Joo Weon Park

Poongyeub Lee

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

In an array of nonvolatile memory cells, as many memory cells as desired and indeed even the entire array of memory cells may be placed in a single region of the bulk, illustratively a p-well. Peripheral circuitry is used to in effect section the memory array into blocks and groups of blocks, and to establish suitable biasing and counter-biasing within those blocks and groups during page or block erase operations to limit erase disturb. Each group is provided with its own set of voltage switches, which furnishes the bias voltages for the various modes of operation, including erase. Each of the voltage switches furnish either a large positive voltage when its group is selected, or a large negative voltage when its group is unselected. The size of the group is established as a compromise between degree of erase disturb and substrate area required for the voltage switches.

Nonvolatile memory and method of operation thereof to control erase disturb

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Pleasanton, CA, United States of America

Kwangho Kim