摘要:
A novel FLASH-based EEPROM cell, decoder, and layout scheme are disclosed to eliminate the area-consuming divided triple-well in cell array and allows byte-erase and byte-program for high P/E cycles. Furthermore, the process-compatible FLASH cell for EEPROM part can be integrated with FLASH and ROM parts so that a superior combo, monolithic, nonvolatile memory is achieved. Unlike all previous arts, the novel combo nonvolatile memory of the present invention of ROM, EEPROM and FLASH or combination of any two is made of one unified, fully compatible, highly-scalable BN+ cell and unified process. In addition, its cell operation schemes have zero array overhead and zero disturbance during P/E operations. The novel combo nonvolatile memory is designed to meet the need in those markets requiring flexible write size in units of bytes, pages and blocks at a lower cost.
摘要:
A flash memory having over-erased cells eliminated and comprising adjustable erase and program conditions. The maximum and minimum threshold voltages of the cells are measured during the whole erase and program operations. The over-erased cells are shut down by applying a word line voltage lower than the minimum threshold voltage measured previously. Pre-program and repair operations for the over-erased cell are eliminated. Low read voltage is achieved. The erase and program conditions for the gate, source, drain voltage, width of a pulse, and number of pulses are adjustable in accordance with the threshold voltage to optimize the performance. A lookup table stores the relevant gate, source, drain voltage, width of a pulse, and number of pulses with respect to the threshold voltage for the adjustable conditions. The benefits achieved by the operation of the flash memory include high efficiency, long endurance, narrow threshold voltage distribution, low power consumption, and low process-sensitivity.
摘要:
New bias conditions for flash memory cells and X-decoder circuits for providing the bias conditions. In an erasing operation, a positive high voltage is provided to the bulk and a negative high voltage is provided to the control gate for establishing a sufficient electric field to induce electron tunneling effect. In an operation for repairing a cell's threshold voltage, the biased voltages are reversed. A first X-decoder circuit structure is presented for supplying positive and negative high voltages to the memory cells for block erasing or repairing. The first X-decoder circuit structure has a plurality of X-decoder blocks each being constructed in a separated X-decoder well, and the memory cells are fabricated in a separate common array well. A second X-decoder circuit structure is presented to provide an appropriate bias condition for erasing or repairing a small sector of word lines. For the second X-decoder circuit structure, each memory block is fabricated in a separated array well. Separated X-decoder wells are constructed to provide voltages to the word lines of memory blocks. Every word line in a memory block has an X-decoder driver so that the word line can be erased or repaired individually. A new layout is also presented for the construction of the X-decoder circuits.
摘要:
A nonvolatile memory device includes multiple independent nonvolatile memory arrays that concurrently for parallel reading and writing the nonvolatile memory arrays. A parallel interface communicates commands, address, device status, and data between a master device and nonvolatile memory arrays for concurrently reading and writing of the nonvolatile memory arrays and sub-arrays. Data is transferred on the parallel interface at the rising edge and the falling edge of the synchronizing clock. The parallel interface transmits a command code and an address code from a master device and transfers a data code between the master device and the nonvolatile memory device, wherein the data code has a length that is determined by the command code and a location determined by the address code. Reading one nonvolatile memory array may be interrupted for reading another. One reading operation has two sub-addresses with one transferred prior to a command.
摘要:
A nonvolatile memory device includes multiple independent nonvolatile memory arrays that concurrently for parallel reading and writing the nonvolatile memory arrays. A parallel interface communicates commands, address, device status, and data between a master device and nonvolatile memory arrays for concurrently reading and writing of the nonvolatile memory arrays and sub-arrays. Data is transferred on the parallel interface at the rising edge and the falling edge of the synchronizing clock. The parallel interface transmits a command code and an address code from a master device and transfers a data code between the master device and the nonvolatile memory device, wherein the data code has a length that is determined by the command code and a location determined by the address code. Reading one nonvolatile memory array may be interrupted for reading another. One reading operation has two sub-addresses with one transferred prior to a command.
摘要:
A nonvolatile memory device includes multiple independent nonvolatile memory arrays that concurrently for parallel reading and writing the nonvolatile memory arrays. A serial interface communicates commands, address, device status, and data between a master device and nonvolatile memory arrays for concurrently reading and writing of the nonvolatile memory arrays and sub-arrays. Data is transferred on the serial interface at the rising edge and the falling edge of the synchronizing clock. The serial interface transmits a command code and an address code from a master device and transfers a data code between the master device and the nonvolatile memory device, wherein the data code has a length that is determined by the command code and a location determined by the address code. Reading one nonvolatile memory array may be interrupted for reading another. One reading operation has two sub-addresses with one transferred prior to a command.
摘要:
A nonvolatile memory device includes multiple independent nonvolatile memory arrays that concurrently for parallel reading and writing the nonvolatile memory arrays. A serial interface communicates commands, address, device status, and data between a master device and nonvolatile memory arrays for concurrently reading and writing of the nonvolatile memory arrays and sub-arrays. Data is transferred on the serial interface at the rising edge and the falling edge of the synchronizing clock. The serial interface transmits a command code and an address code from a master device and transfers a data code between the master device and the nonvolatile memory device, wherein the data code has a length that is determined by the command code and a location determined by the address code. Reading one nonvolatile memory array may be interrupted for reading another. One reading operation has two sub-addresses with one transferred prior to a command.
摘要:
A memory cell device is achieved. The memory cell device comprises a first transistor having gate, drain, and source. A second transistor has gate, drain, and source. The first transistor drain is coupled to an array bit line. The second transistor source is coupled to an array source line. The first transistor source is coupled to the second transistor drain. The first transistor and the second transistor comprise one Flash transistor and one mask ROM transistor. The programmed state of the mask ROM transistor can be read.
摘要:
A nonvolatile memory device includes multiple independent nonvolatile memory arrays that concurrently for parallel reading and writing the nonvolatile memory arrays. A serial interface communicates commands, address, device status, and data between a master device and nonvolatile memory arrays for concurrently reading and writing of the nonvolatile memory arrays and sub-arrays. Data is transferred on the serial interface at the rising edge and the falling edge of the synchronizing clock. The serial interface transmits a command code and an address code from a master device and transfers a data code between the master device and the nonvolatile memory device, wherein the data code has a length that is determined by the command code and a location determined by the address code. An enable signal defines a beginning and termination of a reading or writing operation. Reading one nonvolatile memory array may be interrupted for another operation and then resumed.
摘要:
A method and apparatus for operation for the NAND-like dual charge retaining transistor NOR flash memory cells begins by erasing, verifying over-erasing the threshold voltage level of the erased charge retaining transistors to an erased threshold voltage level. Then method progresses by programming one of two charge retaining transistors of the NAND-like dual charge retaining transistor NOR flash memory cells to a first programmed threshold voltage level, and programming the other of the two charge retaining transistors of the NAND-like dual charge retaining transistor NOR flash memory cells to the first programmed threshold voltage level or to a second programmed threshold voltage level. Combinations of the erased threshold voltage level and the first and second programmed threshold voltage levels determine an internal data state of the NAND-like dual charge retaining transistor NOR flash memory cells which are then decoded to ascertain the external data logical state.