Abstract: The present invention is provided with: subword drivers SWD for driving subword lines SWL, a selection circuit for supplying either negative potential VKK1 or VKK2 to the subword drivers SWD, and memory cells MC that are selected in the case when the subword line SWL is set to an active potential VPP and are not selected in the case when the subword line SWL is either a negative potential VKK1 or VKK2.

Abstract: A semiconductor device is disclosed, which comprises: a memory cell, first and second bit lines, a switch between the first and second bit lines, a sense amplifier, a sense amplifier driving circuit driving the sense amplifier with first and second voltages, a precharge circuit precharging the first bit line, and a control circuit. The control circuit performs a read operation so that the first and second bit lines are disconnected from each other and the first bit line is precharged to a precharge voltage, during a first period. Thereafter, the control circuit performs a restoring operation in a state where the first and second bit lines are connected to each other and the precharging of the first bit line is cancelled, during a second period after the first period.

Abstract: A semiconductor device having hierarchical bit lines is disclosed, which comprises: a first global bit line; first and second local bit lines coupled in common to the first global bit line; first and second power lines; a first transistor coupled between the first local bit line and the first power line; a second transistor coupled between the second local bit line and the second power line; a third transistor coupled between the first and second power lines.

Abstract: Disclosed herein is a semiconductor device comprising local bit lines, a global bit line, local switch control lines, main switch control lines, hierarchical switches controlling electrical connections between the local bit lines and the global bit line in response to potentials of the local switch control lines, local switch drivers driving the local switch control lines in response to potentials of the main switch control lines, and main switch drivers selectively activating the main switch control lines.

Abstract: Disclosed herein is a semiconductor device comprising local bit lines, a global bit line, local switch control lines, main switch control lines, hierarchical switches controlling electrical connections between the local bit lines and the global bit line in response to potentials of the local switch control lines, local switch drivers driving the local switch control lines in response to potentials of the main switch control lines, and main switch drivers selectively activating the main switch control lines.

Abstract: Disclosed herein is a device includes first and second memory mats. The first memory mat includes first and defective memory cells and first local bit lines coupled to a first global bit line. Each of the first local bit lines is coupled to associated ones of the first memory cells, one of the first local bit lines is further coupled to the defective memory cell. The second memory mat includes second and redundant memory cells and second local bit lines coupled to a second global bit line. Each of the second local bit lines is coupled to associated ones of the second memory cells, one of the second local bit lines is further coupled to the redundant memory cell. The device further includes a control circuit accessing the redundant memory cell when the access address information coincides with the defective address information that designates the defective memory cell.

Abstract: A first data amplifier connects to a first memory cell identified by an X-address signal and a selection signal obtained by predecoding a Y-address signal. A second data amplifier connects to a second memory cell identified by the X-address signal and a delayed selection signal obtained by delaying the selection signal. A generator generates a delayed operation clock signal by delaying an operation clock signal of the first data amplifier. A timing controller receives a first control signal for controlling an operation of the first data amplifier and a second control signal for controlling an operation of the second data amplifier, outputs the first control signal to the first data amplifier at a timing according to the operation clock signal, and outputs the second control signal to the second data amplifier at a timing according to the delayed operation clock signal.

Abstract: Disclosed herein is a device that includes: a first control element that controls an amount of current flowing between a second line and a first node according to a potential of a first line; a second control element that controls an amount of current flowing between the first line and the first node according to a potential of the second line; a first control circuit that performs a first operation to fix potentials of the first and second lines at a first potential; a second control circuit that performs a second operation to connect the first node to the second node; and a third control circuit that fixes a potential of the first node at a second potential after the first control circuit stops the first operation until the second control circuit starts the second operation.

Abstract: A semiconductor device having hierarchical bit lines is disclosed, which comprises: a first global bit line; first and second local bit lines coupled in common to the first global bit line; first and second power lines; a first transistor coupled between the first local bit line and the first power line; a second transistor coupled between the second local bit line and the second power line; a third transistor coupled between the first and second power lines.

Abstract: Disclosed herein is a semiconductor device that includes a plurality of memory cells; a local bit line coupled to the memory cells; a global bit line; and a first switch circuit coupled between the global bit line and the local bit line, the first switch circuit electrically connecting the local bit line to the global bit line when at least one of first and second control signals is in an active state, and the first switch circuit electrically disconnecting the local bit line to the global bit line when both of the first and second control signals are in an inactive state.

Abstract: Disclosed herein is a semiconductor device comprising local bit lines, a global bit line, local switch control lines, main switch control lines, hierarchical switches controlling electrical connections between the local bit lines and the global bit line in response to potentials of the local switch control lines, local switch drivers driving the local switch control lines in response to potentials of the main switch control lines, and main switch drivers selectively activating the main switch control lines.

Abstract: A semiconductor device includes a plural number of sense amplifiers that sense at least two data in parallel and that operate under a first frequency, and a multiplexer that operates under a second frequency higher than the first frequency and that sequentially serially outputs the data sensed in parallel. The semiconductor device also includes a driver circuit having a latch circuit connected to an output of the multiplexer, and an output driver circuit connected to the latch circuit and operating under the second frequency. The voltage of a power supply of the sense amplifiers is the same as the voltage of a power supply of the output driver circuit. The power supply of the sense amplifiers and the power supply of the output driver circuit are connected to respective different power supply lines.

Abstract: To comprise a memory cell array, a read amplifier that is provided outside the memory cell array and amplifies data read from the memory cell array, a write amplifier that is provided outside the memory cell array and amplifies data to be written in the memory cell array, and a relief storage cell that is provided outside the memory cell array and connected to an input terminal of the read amplifier and an output terminal of the write amplifier via a switch. With this configuration, a timing of operating a main amplifier and the relief storage cell does not need to be changed depending on a position of a memory block. Further, the number of components required for connecting to the relief storage cell can be minimized.

Abstract: A first data amplifier connects to a first memory cell identified by an X-address signal and a selection signal obtained by predecoding a Y-address signal. A second data amplifier connects to a second memory cell identified by the X-address signal and a delayed selection signal obtained by delaying the selection signal. A generator generates a delayed operation clock signal by delaying an operation clock signal of the first data amplifier. A timing controller receives a first control signal for controlling an operation of the first data amplifier and a second control signal for controlling an operation of the second data amplifier, outputs the first control signal to the first data amplifier at a timing according to the operation clock signal, and outputs the second control signal to the second data amplifier at a timing according to the delayed operation clock signal.

Abstract: A semiconductor device includes a plural number of sense amplifiers that sense at least two data in parallel and that operate under a first frequency, and a multiplexer that operates under a second frequency higher than the first frequency and that sequentially serially outputs the data sensed in parallel. The semiconductor device also includes a driver circuit having a latch circuit connected to an output of the multiplexer, and an output driver circuit connected to the latch circuit and operating under the second frequency. The voltage of a power supply of the sense amplifiers is the same as the voltage of a power supply of the output driver circuit. The power supply of the sense amplifiers and the power supply of the output driver circuit are connected to respective different power supply lines.

Abstract: To comprise a memory cell array, a read amplifier that is provided outside the memory cell array and amplifies data read from the memory cell array, a write amplifier that is provided outside the memory cell array and amplifies data to be written in the memory cell array, and a relief storage cell that is provided outside the memory cell array and connected to an input terminal of the read amplifier and an output terminal of the write amplifier via a switch. With this configuration, a timing of operating a main amplifier and the relief storage cell does not need to be changed depending on a position of a memory block. Further, the number of components required for connecting to the relief storage cell can be minimized.

Abstract: A semiconductor memory device includes a first circuit which generates a first potential lower than the external power supply voltage, a second circuit which generates a second potential lower than the first potential, a capacitor charged to the first potential, a bit line connected to a memory cell, a sense amplifier which performs sense operation to amplify a potential on the bit line to the second potential, and a connection control circuit which connects the first circuit to the sense amplifier within a first time period from a start of the sense operation, and which connects the second circuit to the sense amplifier after the lapse of the first time period. The first circuit is enabled before the start of the sense operation and is disabled after the completion of charging of the capacitor, and the output of the first circuit is thereby set in a floating state.

Abstract: A wafer-level burn-in test for a write operation to memory cells is disclosed. The memory cells are associated with a column switch transistor having a gate. In accordance with the method, a voltage level supplied for the gate is changed in correspondence with a level written into the memory cells. When a stress voltage is written into the memory cells, the gate of the column switch transistor is applied with a high level voltage, ex. a voltage higher than a normal VDD. When a zero voltage is written into the memory cells, the gate of the column switch transistor is applied with a low level voltage, ex. a zero voltage or a negative voltage.

Abstract: When a command is input to a semiconductor memory device, a sub-threshold current is reduced to a predetermined value corresponding to the command. After the reduction of the sub-threshold current is completed, the semiconductor memory device starts to operate corresponding to the command.

Abstract: A semiconductor memory device has column selecting switches in a hierarchical structure. A plurality of local column selecting switches for controlling connections between bit lines and local I/O lines. A global column selecting switch connects column selecting lines and four local column selecting switches when a bit precharging signal becomes low in level for stopping precharging the bit lines. As the column selecting switches are in a hierarchical structure including the global column selecting switch that is directly controlled by the column selecting lines and the local column selecting switches that are controlled by the global column selecting switch, a load on the column selecting lines is reduced for high-speed operation. Even when bit lines are divided into a greater number of bit lines, the number of column selecting switches that are energized by a single column selecting line is not increased, and a signal delay is prevented from occurring.