Abstract:
A method for improving sub-word line response comprises generating a variable substrate bias determined by at least one user parameter. The variable substrate bias is applied to a sub-word line driver in a selected sub-block of a memory. A voltage disturbance on a sub-word line in communication with the sub-word line driver is minimized by modifying a variable substrate bias of the sub-word line driver to change a transconductance of the sub-word line driver thereby.
Abstract:
An apparatus and method of page program operation is provided. When performing a page program operation with a selected memory device, a memory controller loads the data into the page buffer of one selected memory device and also into the page buffer of another selected memory device in order to store a back-up copy of the data. In the event that the data is not successfully programmed into the memory cells of the one selected memory device, then the memory controller recovers the data from the page buffer of the other memory device. Since a copy of the data is stored in the page buffer of the other memory device, the memory controller does not need to locally store the data in its data storage elements.
Abstract:
A phase change memory is disclosed. The phase change memory has a plurality of block units. The block units are alternately selected. The alternate block unit selection suppresses peak current ground bouncing on sub-wordline and connected ground line through sub-wordline driver transistor. An alternate bitline selection avoids adjacent cell heating interference in the selected block unit.
Abstract:
A memory controller is unaware of device types (DTs) of a plurality (N) of series-connected memory devices in an interconnection configuration. Possible DTs include, e.g., random access memories and Flash memories. First, the memory controller sends a specific DT (“don't care”) and an initial number of binary code to the first device of the interconnection configuration and the binary code is propagated through the devices. Each device performs a “+1” calculation regardless of the DT. The last device provides the memory controller with Nד+1” from which the memory controller can obtain the number N of devices in the interconnection configuration. Thereafter, the memory controller sends a search number (SN) of binary code and a search DT for DT matching that propagate through the devices. Each device performs DT match determination of “previous match”, “present match” and “don't care match”. Based on the match determination, the SN and search DT are or not modified. The modified or non-modified SN and DT are propagated through the devices. Such processes are repeated. From the propagated SN and DT and the previously recognized number of the devices, the memory controller can identify the DT of each device in the interconnection configuration.
Abstract:
Status indication in a system having a plurality of memory devices is disclosed. A memory device in the system includes a plurality of data pins for connection to a data bus. The memory device also includes a status pin for connection to a status line that is independent from the data bus. The memory device also includes first circuitry for generating, upon completion of a memory operation having a first duration, a strobe pulse of a second duration much shorter than the first duration. The strobe pulse provides an indication of the completion of the memory operation. The memory device also includes second circuitry for outputting the strobe pulse onto the status line via the status pin.
Abstract:
An apparatus, system, and computer-implemented method for controlling data transfer between a plurality of serial data link interfaces and a plurality of memory banks in a semiconductor memory is disclosed. In one example, a flash memory device with multiple links and memory banks, where the links are independent of the banks, is disclosed. The flash memory devices may be cascaded in a daisy-chain configuration using echo signal lines to serially communicate between memory devices. In addition, a virtual multiple link configuration is described wherein a single link is used to emulate multiple links.
Abstract:
An access buffer, such as page buffer, for writing to non-volatile memory, such as Flash, using a two-stage MLC (multi-level cell) operation is provided. The access buffer has a first latch for temporarily storing the data to be written. A second latch is provided for reading data from the memory as part of the two-stage write operation. The second latch has an inverter that participates in the latching function when reading from the memory. The same inverter is used to produce a complement of an input signal being written to the first latch with the result that a double ended input is used to write to the first latch.
Abstract:
A memory controller is unaware of device types (DTs) of a plurality (N) of series-connected memory devices in an interconnection configuration. Possible DTs include, e.g., random access memories and Flash memories. First, the memory controller sends a specific DT (“don't care”) and an initial number of binary code to the first device of the interconnection configuration and the binary code is propagated through the devices. Each device performs a “+1” calculation regardless of the DT. The last device provides the memory controller with Nד+1” from which the memory controller can obtain the number N of devices in the interconnection configuration. Thereafter, the memory controller sends a search number (SN) of binary code and a search DT for DT matching that propagate through the devices. Each device performs DT match determination of “previous match”, “present match” and “don't care match”. Based on the match determination, the SN and search DT are or not modified. The modified or non-modified SN and DT are propagated through the devices. Such processes are repeated. From the propagated SN and DT and the previously recognized number of the devices, the memory controller can identify the DT of each device in the interconnection configuration.
Abstract:
A plurality of memory devices of mixed type (e.g., DRAMs, SRAMs, MRAMs and NAND-, NOR- and AND-type Flash memories) are serially interconnected. Each device has device type information on its device type. A specific device type (DT) and a device identifier (ID) contained in a serial input (SI) are fed to one device of the serial interconnection. The device determines whether the fed DT matches the DT of the device. In a case of match, a calculator included in the device performs calculation to generate an ID for another device and the fed ID is latched in a register of the device. The generated ID is transferred to another device of the serial interconnection. In a case of no match, the ID generation is skipped and no ID is generated for another device. Such a device type match determination and ID generation or skip are performed in all devices of the serial interconnection. In cases of different device types being separately provided to the interconnected devices, sequential IDs are generated in each of the different device types and also the total number of each device type are recognized. In a case of a “don't care” code is provided to the interconnected devices, sequential IDs are generated and also, the total number of the interconnected devices is recognized, regardless of the type differences.
Abstract:
A method for programming NAND flash cells to minimize program stress while allowing for random page programming operations. The method includes asymmetrically precharging a NAND string from a positively biased source line while the bitline is decoupled from the NAND string, followed by the application of a programming voltage to the selected memory cell, and then followed by the application of bitline data. After asymmetrical precharging and application of the programming voltage, all the selected memory cells will be set to a program inhibit state as they will be decoupled from the other memory cells in their respective NAND strings, and their channels will be locally boosted to a voltage effective for inhibiting programming. A VSS biased bitline will discharge the locally boosted channel to VSS, thereby allowing programming of the selected memory cell to occur. A VDD biased bitline will have no effect on the precharged NAND string, thereby maintaining a program inhibited state of that selected memory cell.