Micron Technology Incorporated

Cypress Semiconductor Corporation

Kevin Widmer

Frankie F Roohparvar

Cliff Zitlaw

Anthony Le

A memory subsystem is disclosed. The memory subsystem includes a serial peripheral interface (SPI) double data rate (DDR) volatile memory component, a serial peripheral interface (SPI) double data rate (DDR) non-volatile memory component coupled to the serial peripheral interface (SPI) double data rate (DDR) volatile memory component and a serial peripheral interface (SPI) double data rate (DDR) interface. The serial peripheral interface (SPI) double data rate (DDR) interface accesses the serial peripheral interface (SPI) double data rate (DDR) volatile memory component and the serial peripheral interface (SPI) double data rate (DDR) non-volatile memory component where data is accessed on leading and falling edges of a clock signal.

High speed serial peripheral interface memory subsystem

A synchronous flash memory includes an array of non-volatile memory cells. The memory device has a package configuration that is compatible with an SDRAM. The memory device can comprise an array of memory cells having N addressable sectors, and control circuitry to control erase or write operations on the array of memory cells. Protection circuitry can be coupled to the control circuitry to selectively prevent erase or write operations from being performed on both first and last sectors of the N addressable sectors. The protection circuitry can comprise a multi-bit register having a first bit corresponding to the first sector and a second bit corresponding to the last sector.

Top/bottom symmetrical protection scheme for flash

A flash memory device having a pipelined RAS/CAS architecture is logically organized as an array of rows and columns of multi-bit flash memory cells each capable of being selectively programmed to have a threshold voltage corresponding to one of a plurality of multi-bit bit-sets. In one embodiment, the memory device is adapted to perform a burst read operation in which a row of flash memory cells is sensed and latched and subsequently outputted from the device on consecutive clock cycles following a sense latency period. In accordance with one aspect of the invention, the pipelined architecture allows for a second burst read operation to be initiated prior to completion of the first, such that the sense latency periods for all but the first of a series of successive burst read operations are hidden, enabling the memory device to perform comparably to a memory device having conventional flash memory cells.

Flash memory architecture for optimizing performance of memory having multi-level memory cells

An improved memory device and architecture has been detailed that enhances a Flash memory device that has an SDRAM compatible interface. The memory device employs a virtual paging scheme that allows the memory to have an efficient Flash internal structure, while logically re-mapping this architecture externally to a compatible virtual SDRAM architecture. This allows for access and operation of the improved memory device with a compatible SDRAM controller device, while Flash specific functions can be performed with an SDRAM command sequence. Internal to the memory, memory array banks are divided into four equal segments by row range and logically re-mapped by placing the segments virtually beside each other. This forms a virtual memory bank structure of equivalent rows and columns as a comparable SDRAM device. Additionally, the improved memory device may also have an extended interface that allows for direct access to the internal Flash memory architecture without logical abstraction.

Synchronous flash memory with virtual segment architecture

A flash memory has been described that has an interface corresponding to a rambus dynamic random access memory (RDRAM). The memory samples commands and addresses on a rising edge of a clock signal. The read and write data are provided on both the rising edge and the falling edge of the clock signal.

Flash memory with RDRAM interface

An improved memory device and architecture has been detailed that enhances a Flash memory device that has an SDRAM compatible interface. The memory device employs a virtual paging scheme that allows for the architecture of the memory to implement an efficient Flash memory structure internally. Externally, the memory logically maps the internal Flash architecture to an SDRAM compatible interface and virtual architecture, allowing for memory access and operation with a compatible SDRAM controller device. A double data rate interface is provided to allow data to be input and output from the memory in synchronization with both rising and falling edges of a clock signal.

DDR synchronous flash memory with virtual segment architecture

A flash memory has erase blocks aligned primarily with array rows and secondarily with array rows. This architecture allows data to be stored across numerous pages without risking accidental erasure caused by crossing multiple erase blocks. As a result, non-volatile memory devices to be more easily substituted for volatile memory devices. In one embodiment, a flash memory includes an array of memory cells that have a plurality of adjacent pages. Addresses of the memory cells are scrambled within the pages to define erase blocks that cross the page boundaries.

Growing community of inventors

San Carlos, CA, United States of America

Kevin Widmer