摘要:
An electronic blackboard device capable of performing color printing. Data read by an image sensor is converted to digital data by an A/D converter and provided via a shading correcting circuit and a converter to a printer control circuit, which causes a color printer to print the appropriate data in a color corresponding to a marker.
摘要:
In erasing, electrons are simultaneously injected into floating gates from sources of a plurality of memory cells. Thus, the threshold voltages of the plurality of memory cells are increased. In programming, electrons are emitted from a floating gate of a selected memory cell to a drain. Thus, the threshold voltage of the selected memory cell is reduced.
摘要:
A source line of a memory array included in a flash memory is set to a 3V potential by a source line circuit, a power supply voltage of 6V is applied to a sense amplifier, and 3V is applied as the ground potential. After the setting of such potential conditions, reading of the memory array is performed. When current flows to the memory cells as a result of reading, it means that the memory cell has been erased. If the current does not flows through the memory cell, erasure pulse is applied again and every memory cell is verified.
摘要:
A collective erasure type nonvolatile semiconductor memory device which allows use of redundant structure to word lines is provided. A row address buffer having address converting function simultaneously selects a plurality of physically adjacent word lines from a memory array in programming before erasure. Programming before erasure is effected on the memory cells on the simultaneously selected word lines. Even when physically adjacent word lines are short-circuited between each other, programming high voltage can be transmitted to the defective word lines, as these word lines are selected simultaneously. Therefore, the memory cells on the defective word lines can be programmed before erasure, so that over erasure at the time of collective erasing operation can be prevented. Thus, redundant structure for replacing defecting word lines by spare word lines can be utilized.
摘要:
A column latch and a high voltage switch connected to each bit line are eliminated, and an address counter and the data latch are newly provided. The data latch is arranged between an I/O buffer and a Y gate. In a programming cycle, the address counter is activated and transfer gates in the Y gate are successively selected. Consequently, a high voltage Vpp or 0V is applied periodically to bit lines in the memory cell array in accordance with the write data stored in the data latch.
摘要:
A column latch and a high voltage switch connected to each bit line are eliminated, and an address counter and the data latch are newly provided. The data latch is arranged between an I/O buffer and a Y gate. In a programming cycle, the address counter is activated and transfer gates in the Y gate are successively selected. Consequently, a high voltage Vpp or 0 V is applied periodically to bit lines in the memory cell array in accordance with the write data stored in the data latch.
摘要:
A plurality of memory cell transistors having floating gates are disposed in a matrix in the direction of row and column to form a memory cell array. The memory cell array is divided into a plurality of sectors for every predetermined row. In each sector, sector selecting transistors and sub bit lines are provided, so that erasing and programming can be made for each sector. Therefore, total erasing for sector becomes possible, and since no voltage is applied to sub bit lines and word lines of non-selected sectors, the number of operations of preventing writing into non-selected memory cells is as many as the word lines included in one sector.
摘要:
Externally inputted data of one word line is temporarily stored in a latch circuit. In the writing cycle, the data stored and held in the latch circuit is collectively written in memory transistors connected to the selected word line. On this occasion, 0 V is applied to one of the control gate and the drain of the memory transistor in which "0" is written and a high voltage V.sub.PP is applied to the other of the control gate and the drain. Therefore, not only in the erasing cycle but also in the writing cycle, the operation is carried out by the movement of charges caused by the electron tunneling.
摘要:
A semiconductor device in which a capacitor of a switched-capacitor included in an RC network for defining the rise time of a programming high-voltage pulse signal of an EEPROM is formed of an oxide film having a thickness corresponding to the thickness of a tunnel oxide film or an oxide film between a floating gate and a control gate so that a shift amount of a threshold voltage of a memory transistor is made constant even if the thickness of the tunnel oxide film or the oxide film between the floating gate and the control gate is deviated from a designed value.
摘要:
A text inputting device includes a keyboard for inputting a string of characters of a first kind by keying keys and a first device for displaying characters of a second kind corresponding to the character string supplied from the keyboard as candidate characters and selecting a desired character of the second kind from the candidate characters for supplying it to a processor. A second device is also provided for reading a character of the second kind corresponding to a mnemonic code in the character string supplied from the keyboard for supplying it to the processor. In order to determine whether the first or second device is used, a selection switch is provided for selectively activating the first or the second device when a character of the second type is to be inputted. Further, to assist in teaching the mnemonic code, when the first device is selected, either visual or oral correspondence is provided between the selected candidate character and its corresponding mnemonic code. The invention is particularly useful in inputting complex texts such as Japanese or other language texts.