Micron Technology Incorporated

Samuel A Shapero

Theodore T Pekny

Peter Sean Feeley

Wanmo Wong

Brady L Keays

Kirubakaran Periyannan

One or more techniques are provided for restricting access to protected modes of operation in a memory device. In one embodiment, detection circuitry is provided and configured to receive and evaluate a protected mode entry sequence for accessing a protected mode of operation. The detection circuitry may be further configured to temporarily enable an output pin on a serial interface between the memory device and a master device to receive inputs, such that a entry sequence may be entered on both the input and output pins. In another embodiment, the detection circuitry may be enabled only if a security code is first provided, thus requiring both the correct security code and entry sequence before protected mode access is allowed. The memory device may also include a parallel NAND memory array, and detection logic may be further configured to enable a serial-to-parallel NAND translator once protected mode access is allowed.

SPI NAND protected mode entry methodology

One or more techniques are provided for programming a flash memory device. In one embodiment, the memory device is programmed such that a data pattern written to a page in the memory device has encoded therein an expected count value corresponding to the number of times a first binary value occurs in the data pattern. The data pattern includes the program data and the expected count value, and is written to the page in a single operation. The expected count value may be stored in a count field in the management area of the page. During a page read operation, the expected count value is compared to the actual count of the number of bits having the first binary value in the data area of the page. If the expected count is equal to the actual count, then the program data is determined to be valid.

Growing community of inventors

Atlanta, GA, United States of America

Samuel A Shapero