Abstract: Some embodiments of the invention may use a single control line signal as both a wake up signal and as an indicator of a device selection command. In a command-based protocol on a non-volatile memory bus, a host memory controller may assert a signal on a control line to bring all the memory devices on the bus into an operational mode, while concurrently placing a device selection command on the input/output lines. The memory device selected by the selection command may remain operational to perform a sequence of operations as directed by the host controller. The remaining (non-selected) memory devices may return to a sleep mode until a new signal on the control line is received, indicating a new selection command.

Abstract: Some embodiments of the invention may use a single control line signal as both a wake up signal and as an indicator of a device selection command. In a command-based protocol on a non-volatile memory bus, a host memory controller may assert a signal on a control line to bring all the memory devices on the bus into an operational mode, while concurrently placing a device selection command on the input/output lines. The memory device selected by the selection command may remain operational to perform a sequence of operations as directed by the host controller. The remaining (non-selected) memory devices may return to a sleep mode until a new signal on the control line is received, indicating a new selection command.

Abstract: A single status register, capable of providing status for simultaneous read-while-write operation on a flash memory array is described. The status of the memory array is reported to the user based on two partitions. A microcontroller is used to traffic the status register to memory array communication.

Abstract: Briefly, in accordance with an embodiment of the invention, a method and system to retrieve information from a memory is provided. The method may include transferring information from the memory in response to at least two synchronous burst read requests using pipelining.

Abstract: Briefly, in accordance with an embodiment of the invention, a method and system to retrieve information from a memory is provided. The method may include transferring information from the memory in response to at least two synchronous burst read requests using pipelining.

Abstract: A burst transfer operation with a memory device can be suspended and resumed without having to provide the current memory address when it is resumed. A chip enable signal to the memory device can be deasserted to initiate the suspend operation and place the memory device in a low power standby mode. When the chip enable signal is reasserted, the memory device can be reactivated and the burst transfer can continue where it stopped, without any setup commands. The current address counter and other bus transfer parameters can be saved within the memory device during the suspend operation. When the suspend operation is terminated by reasserting the chip enable signal, the memory device can resume the transfer using the saved parameters.

Abstract: A multilevel cell memory may use an architecture in which bits from different words are stored in the same multilevel memory cell. This may improve access time because it is not necessary to sense both cells before the word can be outputted. Therefore, the access time may be improved by removing a serial element from the access chain.

Abstract: A multilevel cell memory may use an architecture in which bits from different words are stored in the same multilevel memory cell. This may improve access time because it is not necessary to sense both cells before the word can be outputted. Therefore, the access time may be improved by removing a serial element from the access chain.

Abstract: A multilevel cell memory may use an architecture in which bits from different words are stored in the same multilevel memory cell. This may improve access time because it is not necessary to sense both cells before the word can be outputted. Therefore, the access time may be improved by removing a serial element from the access chain.

Abstract: A single status register, capable of providing status for simultaneous read-while-write operation on a flash memory array is described. The status of the memory array is reported to the user based on two partitions. A microcontroller is used to traffic the status register to memory array communication.

Abstract: A method and apparatus for controlling use of an electronic system is described. Use of the electronic system is controlled by programming at least one unique code into an auxiliary memory of the electronic system. The auxiliary memory is a permanently lockable memory that is located outside of a main memory array space. The unique code is compared to at least one component code. Use of the electronic system is controlled based on a predefined relationship between the unique code and the component code.

Abstract: An apparatus for protecting memory blocks in a block-based flash Erasable Programmable Read Only Memory (EPROM) device is disclosed. A non-volatile memory array includes a number of blocks that are capable of being placed in a locked state or an unlocked state. A volatile lock register and transmits a write protect signal and a volatile lock-down register are coupled to a lockable block in the volatile memory array. A hardware override line is coupled to both the lock register and the lock-down register. The hardware override line temporarily overrides operation of the lock-down register when it transmits a signal at a first logic state. The lock down register may be used to prevent programming of an associated lock register. The lock registers and lock down registers may be embodied in static access memory (SRAM) circuits.

Abstract: A memory system having memory cells for storing one of a plurality of threshold levels to store more than a single bit per cell is disclosed. The memory system contains a switch control to permit selection of an operating mode including a multi-level cell mode and a standard cell mode. The memory system further includes a reading circuit to read a single bit per cell when operating in the standard cell mode, and to read multiple bits of data per memory cell when operating in the multi-level cell mode. A program circuit programs a single bit of data per memory cell for addressed memory cells when operating in the standard cell mode, and programs multiple bits of data per memory cell for addressed memory cells when operating in the multi-level cell mode.

Abstract: An operation control method and apparatus are described. The apparatus includes a timer circuit, a blocking circuit and a control circuit. The timer circuit provides a done signal upon completion of timing a predetermined elapsed time interval initiated by a start signal. The blocking circuit receives the done signal and provides the done signal as output if the done signal is not blocked when received. The control circuit receives a begin signal indicating that the operation is to be performed and a limit signal to indicate whether or not a condition exists that would prevent the operation from being completed in a single step. If the limit signal indicates the operation can be completed in the single step, the control circuit starts the timing circuit and controls performance of the single step until the done signal is received.

Abstract: An operation control method and apparatus are described. The apparatus includes a timer circuit, a blocking circuit and a control circuit. The timer circuit provides a done signal upon completion of timing a predetermined elapsed time interval initiated by a start signal. The blocking circuit receives the done signal and provides the done signal as output if the done signal is not blocked when received. The control circuit receives a begin signal indicating that the operation is to be performed and a limit signal to indicate whether or not a condition exists that would prevent the operation from being completed in a single step. If the limit signal indicates the operation can be completed in the single step, the control circuit starts the timing circuit and controls performance of the single step until the done signal is received.

Abstract: A method of quickly aborting an automated program or erase sequence on a nonvolatile memory array in which each operation of the sequence is performed by a write state machine. During each operation of the program or erase sequence, the state of an abort signal is detected to determine whether or not the sequence should be aborted. If the abort signal is in a second state, the sequence continues to the next operation. If the abort signal is in a first state, the write state machine aborts the sequence and the nonvolatile memory array is placed in a read-only mode. The nonvolatile memory array is then available for user access.

Abstract: Schemes for verifying the successful programming of a memory cell having more than two possible states are disclosed. Each program verify reference flash cell is set to have a V.sub.t that defines a boundary of a possible state for the selected flash cell. For a first embodiment, program verify reference flash cells are used in the place of read reference cells to perform a binary search read operation similar to a standard read operation for the memory device architecture. The data sensed by the write verify operation is compared to expected data. For a second embodiment, a single program verify reference flash cell is used to define a threshold voltage beyond which the floating gate of the selected flash cell must be programmed to pass the write verify operation. Thus, for the second embodiment, the program verify reference flash cell is used to verify the analog V.sub.

Abstract: A memory device is disclosed which includes memory cells having m possible states, where m is at least 2. The memory device includes a multiplexed pair of output paths, wherein each output path is coupled to sense the state of a memory cell and includes a read path circuit, a column load circuit, and a comparator. Provided between the pair of output paths is a switching circuit for coupling the comparators to one another in response to a control signal. For single-bit read operations, each output path senses and outputs the data of the associated memory cell, and the control signal is inactive. When the control signal is active, the read path circuit and column load circuit of one of the output paths is disabled and the switching circuit couples the other read path circuit to the second comparator such that the state of the memory cell is sensed by two comparators.

Abstract: A nonvolatile memory includes a first and a second output, a main array having a first and a second column, and a redundant array having a first and a second redundant column. A logic includes a first and a second CAM set. The first CAM set activates the first redundant column to replace the first column if defective. The second CAM set activates the second redundant column to replace the second column if it is defective. A configuration circuit is provided for controlling the logic to selectively couple the first and second columns and the first and second redundant columns to the first and second outputs. When the configuration circuit is in a first state, the logic couples the first redundant column to the first output if it is activated and the second redundant column to the second output if it is activated.

Abstract: A circuit for accessing data which may be stored in a flash EEPROM memory array in sixteen bit quantities has apparatus for writing data to the array in eight bit quantities which quantities may be either the lower or upper byte of a word and appear at identical input terminals, apparatus for writing data to the array in sixteen bit quantities, apparatus for reading data from the array to identical output terminals in eight bit quantities which quantities may be either the lower or upper byte of a word, and apparatus for reading data from the array in sixteen bit quantities. The circuit also has apparatus for reading data from the array in eight and sixteen bit quantities during periods in which an erase operation conducted on sixteen bits is suspended.