摘要:
In a circuit cell band having circuit cells arranged aligned along a linear array, an on-a-cell line is arranged over a prescribed number of circuit cells, in a region different from a line region in which line band is formed on both sides of the circuit cells, for example, and the on-the-cell line is connected to a feed through in a feed through region provided between adjacent circuit cells. Restrictions on the feed through, size of the circuit cell and the lines are removed as much as possible. The circuit cell has also island-shaped impurity regions for fixing a substrate potential, so that latch up immunity is improved. Transistor forming regions having different conductivity types in a circuit cell are arranged in a sandwiched structure, and the circuit cell can be inverted horizontally and/or vertically while maintaining the transistor arrangement in the circuit cell. Therefore, position of the signal input/output port of the circuit cell can be changed in accordance with the layout of external lines, whereby optimization of the external line layout is facilitated.
摘要:
In a synchronous semiconductor memory device of the present invention, a main word driver and a sub decode driver have a function to take in a row decode signal in response to activation of a bank and to maintain the state of the row decode signal. Accordingly, of the circuits associated with row selection, a row pre-decoder, a row decoder and a row system control circuit can operate under a hierarchical power supply structure.
摘要:
A semiconductor memory device includes an SOI substrate, a plurality of word lines, a plurality of bit line pairs, a plurality of memory cells and a plurality of body fixing lines. The plurality of word lines are disposed in the row direction on the SOI substrate. The plurality of bit line pairs are disposed in the column direction on the SOI substrate. The plurality of memory cells are located on the SOI substrate and each are disposed correspondingly to one of crossings between the plurality of word lines and the plurality of bit line pairs. Each of the plurality of memory cells includes a capacitor and a transistor. The transistor is connected between the capacitor and one bit line in the corresponding bit line pair. The transistor is turned on in response to the potential of the corresponding word line. The plurality of body fixing lines are disposed on the SOI substrate. The plurality of body fixing lines are supplied with a predetermined potential. The transistors in the plurality of memory cells have source regions, drain regions and body regions located between the source and drain regions. The body regions of the transistors in the plurality of memory cells are connected to the plurality of body fixing lines.
摘要:
Read drivers which are provided in correspondence to simultaneously selected plural bits of memory cells are wired-OR connected to internal read data buses which in turn are provided in correspondence to a plurality of memory cell arrays respectively. A test mode circuit is provided for the internal read data buses for detecting coincidence/incoincidence of logics of signal potentials on these internal read data bus lines. In a test operation, all read drivers are activated to read selected memory cell data on the corresponding internal read data bus lines.
摘要:
A data output drive transistor is rendered conductive when the potential of an internal node attains an H level, whereby an output node is discharged to the level of ground potential. When the drive transistor is turned on, the output node is discharged to the level of ground potential at high speed. This drive transistor is turned on for a predetermined time period when output of a high level data is completed, whereby the output node is discharged to the level of the ground potential for a predetermined time period. As a result, the potential of the output node is lowered from a high level to an intermediate level, so that the amplitude of a subsequent output signal is reduced. An output circuit that can effectively prevent generation of ringing with no increase in the access time is provided. A countermeasure is provided to suppress a ringing at output node which drives the output node at high speed when the output node potential attains a potential at which no ringing is caused. A stable output signal is provided at high speed.
摘要:
Two NAND gates are provided corresponding to each of a plurality of pads. By connecting a mode switching pad to power supply potential or ground potential, one of the two NAND gates provided corresponding to each pad is activated, and the other NAND gate is non-activated. As a result, different mode select signals are provided from the output of each NAND gate.
摘要:
Between an external power supply line and an internal power supply line in which an internal power supply potential is transmitted on a substrate region, a high voltage conducting mechanism is provided, which is rendered conductive when a transitional high voltage surge is generated at the external power supply line by electrically connecting the external power supply line and the internal power supply line. Even when the ground line and external power supply line are not arranged parallel to each other, a high voltage conducting mechanism constituted by a field transistor or an insulated gate type field effect transistor having wide width over a long distance can be formed.
摘要:
A constant current source (1) is provided between a power supply (VCC) and an intermediate node (N1) and supplies a reference current (IR) which is a constant current between the power supply (VCC) and the intermediate node (N1). A variable resistor (2) is provided between the intermediate node (N1) and a comparison potential (VL) and its resistance value can be set to a desired value. A current flowing in the variable resistor (2) is a comparison current (IC). An amplifier (3) has an input connected to the intermediate node (N1) and amplifies a potential from the intermediate node (N1) to output a level detection signal (GE). Having this configuration, a potential detecting circuit which ensures a stable and controllable detection level is provided.
摘要:
A DRAM includes an internal boosting circuit, a global power-line, a plurality of blocks, a row decoder, and a POR generating circuit. Each block includes word lines, local power-lines, AND gates, drive transistors, and word line drivers. The AND gate turns a corresponding drive transistor on/off in response to a power on reset signal /POR and a corresponding block select signal. Therefore, all the local boosted power-lines are connected to the global boosted power-line during a power on reset period, whereby all the local boosted power-lines are initially charged up to boosted power supply potential Vpp.
摘要:
A memory array MA.sub.0 is divided into four sub memory arrays by sense amplifier strips. Word drivers belonging to each sub memory array are connected to a corresponding segment boosted signal line. A fuse is connected to each segment boosted signal line. By blowing out a fuse, the sub memory array corresponding to the blown out fuse is no longer used. The sub memory array that is no longer used is exchanged with a spare sub memory array of a spare memory array.