摘要:
A NAND cell type EEPROM has a substrate, parallel bit lines formed above the substrate, and a memory cell section including an array of NAND type cell units associated with the same corresponding bit line. Each of the NAND type cell units has a series-circuit of eight data storage transistors and at least one selection transistor. Each data storage transistor has a floating gate for storing carriers injected thereinto by tunneling and a control gate respectively connected to word lines. A control gate driver circuit is provided in common for all the NAND type cell units that are assisted with the same bit line. Transfer gates are connected between the common driver circuit and the NAND cell units.
摘要:
An electrically erasable programmable read-only memory with a NAND cell structure has parallel bit lines, and memory cells defining NAND cell blocks, each of which has a series-circuit of memory cell transistors. Each transistor has a floating gate and a control gate. Parallel word lines are connected to the control gates of the cell transistors. The first, second and third intermediate voltages are used in the data write mode: the first voltage is lower than the "H" level voltage and higher than the "L" level voltage; the second and third voltages are higher than the first voltage and lower than the "H" level voltage. Data is written into a selected memory cell transistor of a NAND cell block, by applying the "H" level voltage to a word line connected to the selected transistor, applying the second voltage to the remaining unselected word lines, applying a corresponding bit line associated with the selected transistor with one of the first and third voltages which is selected in accordance with a logic level of the data, and applying unselected bit lines with the third voltage, whereby carriers are moved by tunneling from or to the floating gate of the selected memory cell transistor.
摘要:
A highly-integrated semiconductor dynamic random-acess memory is disclosed wherein a reference voltage-generating circuit is connected by voltage-transmission lines to a row-address buffer and a column-address buffer. The reference voltage-generating circuit receives a power-supply voltage and generates first and second reference voltages which are different, by different values, from an ordinary reference potential level. These reference voltages are supplied to the address buffers through the voltage-transmission lines. The first and second reference voltages are adjusted to compensate for a potential deviation which occurs on the voltage-transmission lines. Therefore, even when either reference voltage fluctuates due to an increase in the coupling capacitance between the substrate of the dynamic random-access memory, on the one hand, and the voltage-transmission lines, on the other, both address buffers are prevented from malfunctioning.