摘要:
A method for erasing a flash EEPROM. The flash EEROM includes a number of memory units. First, the flash EEPROM is pre-programmed. Second, the step of erasing the flash EEPROM is performed and the flash EEPROM is then soft-programmed. Subsequently, the final step is performed to determine if the erasing step succeeds.
摘要:
A voltage-boosting generator for reducing the effects due to operating voltage variation and temperature change. The generator comprises a delay line circuit and a voltage boosting circuit. The delay line circuit is used to perform a time delay according to an initial boosting signal and to produce a control signal. The voltage boosting circuit is used to boosted voltage according to the control signal.
摘要:
A NOR-structured semiconductor memory device with a novel configuration of bit line connection is disclosed. The NOR-structured semiconductor memory device comprises a semiconductor memory cell array electrically connected to a plurality of bit lines. The plurality of bit lines are divided into at least four bit line groups. At least two bit lines of each bit line group are coupled to a main bit line through at least two bit line transistors, respectively. Furthermore, the bit lines of the NOR-structured semiconductor memory device are arranged in such a way that at least four adjacent bit lines thereof are selected from four different bit line groups and coupled to four different main bit lines, respectively. During a programming or data reading operation, two adjacent bit lines of the four adjacent bit lines are supplied with a programming voltage or sense current while the other two adjacent bit lines are grounded. Therefore, the NOR-structured semiconductor memory device successfully prevents the programming disturbance or correctly determines the data stored in memory cells at a high speed because no leakage current path is formed.
摘要:
A method for designing a circuit layout of non-neighboring metal bit lines to reduce coupling effect in sensing operation is disclosed. The method comprises providing a memory array having a plurality of bit lines arranged sequentially, wherein every two adjacent bit lines are paired in the sensing operation of a memory cell in the memory array. The first embodiment is presented by assigning a first pair of the bit lines permuted with each other to create a non-neighboring bit line layout. The second embodiment is presented by inserting one of a second pair of the bit lines into a first pair of bit lines to separate the first pair of bit lines in layout design. The method further comprises shrinking the layout space between two adjacent non-paired bit lines. In this way, the method contributes to the reduction of metal bit line coupling effect without any trade off of integrated circuit density by modifying the circuit layout of metal bit lines to a non-neighboring bit line arrangement in a memory array.
摘要:
The present invention provides a dual reference cell sensing scheme for non-volatile memory. A high voltage reference cell and a low voltage reference cell are individually coupled to two sense amplifiers for providing two distinct reference voltages for comparison against the memory cell voltage. The output of the two sense amplifiers is further connected to a second stage sense amplifier to determine the status of the memory. The dual reference cell sensing scheme provides an increased sensing window which increases performance under low voltage application. The dual reference cell sensing scheme can be implemented by either voltage-based, current-based, or ground.
摘要:
A system for reading data in a memory cell includes three comparators, each of which has two inputs. A first reference cell having a low reference voltage is coupled to one input of the first comparator. A second reference cell having a high reference voltage is coupled to one input of the second comparator. A memory cell having a memory cell voltage is coupled to the other input of the first and second comparators. One input of the third comparator is coupled to the first comparator's output signal, which includes a difference voltage between the memory cell voltage and the low reference voltage. The other input of the third comparator is coupled to the second comparator's output signal, which includes a difference voltage between the memory cell voltage and the high reference voltage. A method and apparatus for reading data in a memory cell also are described.
摘要:
A memory array architecture includes a plurality of memory cells formed into rows and columns. A plurality of bit lines is connected to the memory cells through select transistors. By disposing adjacent bit lines into different metal layers or alternatively interlocating adjacent bit lines, the coupling effect between bit lines can be effectively reduced, and thus can improve reading speed of memory while performing read operation.
摘要:
A method and structure for testing embedded flash memory including a memory array and a logic element. A control transistor is disposed and is connected between a sense amplifier and an I/O buffer in the memory array, and a speed control pin connected to the logic element in one terminal is coupled to the gate terminal of the control transistor in the other terminal to switch the control transistor on or off. Turning off the control transistor after a test time by the speed control pin closes the channel between the sense amplifier and I/O buffer, and an output signal from the memory array to a test system connected to the logic element is detected with the test system to determine an access time of the memory array.
摘要:
A method for tracking metal bit line coupling effect in sensing a signal received from an array cell within a memory array is disclosed. The method includes that a reference unit with a reference cell is provided, wherein the reference unit induces coupling effect. Then, the memory array and the reference unit are charged to generate a cell signal having coupling effect and a reference signal having coupling effect. Next, a sensing signal is generated from the difference of the cell signal and the reference signal, whereby the coupling effect is compensated. In the read-out operation of the present invention, because of the closeness of two adjacent metal bit lines, the coupling effect is induced in both memory array and reference unit at the same time, so that the coupling effect is compensated. Therefore, precise read-out operation of data stored in a memory cell is made possible, and the reliability of the device is improved by the present invention.
摘要:
A method of reprogramming field-effect memory cells of a memory array of an electrically erasable flash memory device is described. Each cell has a drain, a source, and a control gate. The drains of the cells are electrically connected to a bit line of the memory array. The cells are programmed and erased. The cells are repaired by grounding the sources and the control gates and taking the bit line to a predetermined potential. The memory array is selectively programmed. Other embodiments include repairing field-effect memory cells connected to a source line or part of a word line. Verification may be done between the repair step and selectively programming step.