Other

Hynix Semiconductor Inc.

Stmicroelectronics S.r.l.

Vincenzo Altieri

Rino Micheloni

Roberto Ravasio

Angelo Bovino

Mario De Matteis

A memory has one bus for data, addresses, and commands. A data register is coupled to the bus to store the data written to and read from the memory, a command register is coupled to the bus for receiving memory commands, and an address register is coupled to the bus to address the memory. The memory also includes an Error Correction Code circuit for calculating an ECC. The memory is configured to be responsive to external commands for controlling the operation of the ECC circuit for reading or writing of the ECC that are separate from external commands controlling reads or writes of the memory data. The memory may also include a status register that stores information regarding the passing or failing of the ECC.

Memory with embedded error correction codes

Multi-level programming allows for writing a first and a second bit in selected cells by separately programming the first bit from the second bit. Programming of the first bit determines a shifting from a first threshold level to a second threshold level. Programming of the second bit requires a preliminary reading to detect whether the first bit has been modified, performing a first writing step to bring the cell to a third threshold voltage if the first bit has been modified and performing a second writing step to bring the selected cell to a fourth threshold voltage different from the third threshold level if the first bit has not been modified. For increasing reading and program reliability, during preliminary reading of the second portion a reading result is forced to correspond to the first threshold level.

Method for accessing a multilevel nonvolatile memory device of the flash NAND type

Growing community of inventors

Ercolano, Italy

Vincenzo Altieri