Kabushiki Kaisha Toshiba

Jun-ichi Tsujimoto

Masataka Matsui

Junichi Miyamoto

Mitsuo Isobe

Takayuki Ohtani

Hiroshi Iwai

Nobu Matsumoto

Kimiyoshi Usami

Tetsuya Iizuka

Takayuki Ootani

A CMOS logic circuit consists of a domino gate serving as a logic gate 1 not disposed on a critical path and operating on a lower supply voltage (VDDL) and another domino gate serving as a logic gate 2 operating on a higher supply voltage (VDDH). An output of the logic gate 1 is an input to the logic gate 2. No level converter is arranged between the logic gates 1 and 2, and therefore, the power dissipation of the CMOS logic circuit is small. The CMOS logic circuit is designed according to a method that satisfies timing requirements and maximizes the number of logic gates that operate on the lower supply voltage (VDDL).

Logic circuit and method of designing the same

A semiconductor integrated circuit device is provided which comprises a first charge pumping circuit comprising a plurality of MOS transistors cascade-connected between an input voltage node and a booster output node, where, of all associated nodes, those odd-numbered nodes receive one of first and second clock signals through a corresponding capacitor and those even-numbered nodes receive the other clock signal through a corresponding capacitor, a second charge pumping circuit comprising a plurality of MOS transistors cascade-connected between the input voltage node and the booster output node and equal in number to those of the first charge pumping circuit where, of all associated nodes, those odd-numbered nodes receive one of first and second clock signals through a corresponding capacitor and those even-numbered nodes receive the other clock signal through a corresponding capacitor and the gates of the respective MOS transistors are connected to the gate of the corresponding MOS transistors, and a high resistive element connected to an output terminal of said first charge pumping circuit.

Charge pump circuit having a boosted output signal

A static semiconductor memory comprises a word line, a memory cell array divided into a plurality of blocks in an extending direction of the word line, each block including a plurality of sections each of which includes a plurality of static memory cells, a controller, a section data line provided for each section, first sense amplifiers, a block data line provided for each block, second sense amplifiers, a main data line and a latch circuit for latching data on the main data line. The controller selects an arbitrary section in the memory cell array at the time of data readout and controls the reading of data from memory cells included in the selected section. The section data line is supplied with data read out from the memory cells. The first sense amplifiers, coupled at their input terminals to the section data line, are activated only when their associated section is selected. The individual first sense amplifiers in the same block have their output terminals commonly coupled to the block data line. Each second sense amplifier, coupled at its input terminal to the associated block data line, is activated only when the sections belonging to that block are selected. The second sense amplifiers have their output terminals commonly coupled to the main data line.

Static semiconductor memory with section and block sense amplifiers

In a semiconductor memory device with normal word lines and spare word lines, a partial decoder receives and decodes a predetermined two of the bit signals of the original logic levels of an address signal, and two of the bit signals of the complementary logic levels, which correspond to the predetermined two bit signals, and outputs different signal combinations of the predetermined two bit signals and the two corresponding bit signals. A spare word line selecting circuit receives the different signals and selects one of the different signals in order to select a spare word line which corresponds to a normal word line to which a defective cell is connected. The partial decoder may be used for both the normal word line selection and the selection of spare word lines. With a device constructed in such a manner, bit signals of an address signal are not directly input to the spare word line selecting circuit, but rather signals of different bit signal combinations are input to it. The spare word line selecting circuit merely selects signals of different combinations, and does not need the partial decoding of the address signal. Therefore, the chip area required for wiring may be remarkably reduced when compared with the conventional memory device.

Semiconductor memory device using partial decoders for redundancy

A power voltage regulator circuit has a power terminal to which an external power voltage is supplied, an output line, and a voltage-drop circuit connected between the power terminal and the output line. The voltage drop circuit includes an N-channel MOS transistor having a drain connected to the power terminal and a source connected to the output line, a constant voltage generator for supplying a voltage, lower than the external power voltage, to a gate of the MOS transistor, and a semiconductor well whose surface area serves as a channel region of the MOS transistor.

Power voltage regulator circuit

The threshold voltage of bit line percharge/equalize MOS transistors is smaller than that of normally ON type bit line pull-up transistors. With this feature, there is no current flows through a bit line from power source V.sub.DD during a read-out operation. The voltage difference between a pair of bit lines can be increased at high speed, thereby increasing the read-out speed.

Static memory with pull-up circuit for pulling-up a potential on a bit

A timer circuit which is used for write and erase time control of a semicondcutor memory, and configured so as to transfer a charge of a charge storage capacitor to a charge pump capacitor through a first transfer gate thereafter to repeatedly effect a discharge operation by using a second transfer gate thereby to gradually reduce a charge of the charge storage capacitor, thus performing a timer operation, characterized in that there is provided a circuit for making an adjustment such that a voltage applied to the charge pump capacitor is smaller than a voltage applied to the charge storage capacitor.

Timer circuit

A semiconductor memory device provided with first and second bit lines, each of which is connected to a memory cell comprising a nonvolatile transistor and a dummy cell comprising a nonvolatile transistor. The first and second bit lines are respectively connected to high voltage generators which are applied at the time of data programming. At the time of data reading, data-detecting and storing means comprising a flip-flop circuit detects data, while amplifying a potential difference between the first and second bit lines. At the time of data writing, the data detecting and storing means temporarily stores data in accordance with the contents of externally supplied writing data. A first switching transistor is provided between the first data input-output node of the data-detecting and storing means and the first bit line. The second switching transistor is connected between the second data input-output node of the data-detecting and storing means and second bit line. The paired switching transistors are controlled in accordance with the operation mode of the memory device.

Programmable semiconductor memory device with combined sense

A sense amplifier comprising a flip-flop circuit is provided for each bit line pair. A first transistor is connected between the flip-flop circuit and V.sub.DD power source. A second transistor is connected between the flip-flop circuit and ground. A control signal for controlling the active state of the flip-flop is applied to the gate of the first transistor, with a minimum time delay. The control signal is also applied to the gate of the second transistor, with a time delay corresponding to that caused by the word line. The timing for rendering each flip-flop circuit in the active state is substantially coincident with the optimum timing of a change in potential on each corresponding bit line.

Semiconductor memory device

A memory matrix array consists of a plurality of memory cells with addresses expressed by a plurality of bits. The parity bit for the data stored in all of the memory cells of each linear memory cell array in the row direction are stored in the corresponding one of a plurality of parity storage cells. Storage is made into second and third parity storage cells, respectively, the parity bits for the data stored in all of the memory cells which are specified such that the corresponding bits of the addresses of the memory cells in the memory matrix array are high in logical level. In a read mode, the parity is read out from the first to third parity storage cells of the parity memory circuit.

Growing community of inventors

Yokohama, Japan

Jun-ichi Tsujimoto