Patents Assigned to Fujitsu VLSI Limited
  • Patent number: 4930108
    Abstract: A semiconductor memory device includes: a first memory cell array having a plurality of memory cells arrayed in a row direction and a column direction; a second memory cell array having at least serial access memory cells corresponding to a single row of the first memory cell array; a first data bus; a second data bus; a third data bus; and a bus switching control circuit for controlling a connection of each of the serial access memory cells to one of the first, second and third data buses and selecting one of the buses to connect the selected data bus to the external of the device. The bus switching control circuit outputs each of bit data in the serial access memory cells serially and alternately to the first and second data buses and, where a plurality of transfer data blocks are serially read out from the second memory cell array, outputs a bit data in the serial access memory cell corresponding to the head or last address in each of the transfer data blocks to the third data bus.
    Type: Grant
    Filed: December 1, 1988
    Date of Patent: May 29, 1990
    Assignees: Fujitsu Limited, Fujitsu VLSI Limited
    Inventor: Tsutomu Sugiyama
  • Patent number: 4912677
    Abstract: A programmable logic device includes an AND array; an OR array; a buffer circuit connected between the AND array and OR array; and a number of decoder arrangements operatively connected to the AND array and OR array. By constituting the buffer such that the AND array and OR array are electrically associated even in a write operation of data, namely, the buffer is brought to an enable state, a logic verify of the buffer becomes unnecessary and, accordingly, a verify/check of written data can be carried out both easily and efficiently.
    Type: Grant
    Filed: June 10, 1988
    Date of Patent: March 27, 1990
    Assignees: Fujitsu Limited, Fujitsu VLSI Limited
    Inventors: Kiyoshi Itano, Kohji Shimbayashi
  • Patent number: 4906862
    Abstract: A semiconductor integrated circuit device has a plurality of terminals, an internal circuit for receiving input signals from the terminals and for outputting output signals to the terminals, where the internal circuit is enabled by a chip enable signal and disabled by a chip disable signal, a non-volatile memory for storing a pin select signal which designates at least a selected one of the terminals as a chip enable control terminal for receiving a control signal which has a first logic level when instructing a power down mode of the semiconductor integrated circuit device, and a buffer part coupled to the terminals and the non-volatile memory for generating the chip enable signal and the chip disable signal responsive to the pin select signal and the control signal.
    Type: Grant
    Filed: October 7, 1988
    Date of Patent: March 6, 1990
    Assignees: Fujitsu Limited, Fujitsu VLSI Limited
    Inventors: Kiyoshi Itano, Kohji Shimbayashi
  • Patent number: 4906868
    Abstract: A logic circuit improves a marginal voltage of a p-channel metal oxide semiconductor (MOS) transistor which is driven through a bipolar complementary metal oxide semiconductor (CMOS) gate. The logic circuit has a bipolar CMOS gate having a CMOS gate and output stage bipolar transistors for receiving an input signal through the CMOS gate, where the CMOS gate and the output stage bipolar transistors are driven by first and second power source voltages. The first power source voltage is higher than the second power source voltage and the output stage bipolar transistors output a signal as an output signal of the bipolar CMOS gate. A p-channel MOS transistor has a gate supplied with the output signal of the bipolar CMOS gate, a source supplied with a third power source voltage, and a drain from which an output signal of the logic circuit is outputted. The third power source voltage is a predetermined value lower than the first power source voltage and higher than the second power source voltage.
    Type: Grant
    Filed: November 10, 1988
    Date of Patent: March 6, 1990
    Assignees: Fujitsu Limited, Fujitsu VLSI Limited
    Inventors: Yasuhiko Maki, Osamu Nomura
  • Patent number: 4899310
    Abstract: A semiconductor memory device having a register and a memory cell array includes a controlling circuit for disconnecting an input/output circuit from a data bus and turning OFF a transfer gate provided between the register and data bus in a first operation mode and for connecting the input/output circuit to the data bus and turning ON the transfer gate in a second operation mode. In the first operation mode, a data read or write operation is performed between the memory cell array and an external circuit, and alternatively in the second operation mode the data read or write operation is performed between the register and the external circuit.
    Type: Grant
    Filed: June 22, 1988
    Date of Patent: February 6, 1990
    Assignees: Fujitsu Limited, Fujitsu VLSI Limited
    Inventors: Fumio Baba, Kazuya Kobayashi, Seiji Enomoto, Hiroaki Ogawa
  • Patent number: 4897560
    Abstract: A semiconductor integrated circuit includes a logic circuit which has first and second transistors constituting an emitter coupled transistor pair and a third transistor which is used as a constant current source, a bias circuit which includes a fourth transistor having an emitter from which a first predetermined voltage is supplied to a base of the third transistor and an impedance having one end coupled to a first power source and another end coupled to a base of the fourth transistor to supply a second predetermined voltage thereto, and a clamping circuit. The clamping circuit is OFF and does not perform a clamping operation with respect to the base of the fourth transistor when the entire semiconductor integrated circuit needs to operate. When the entire semiconductor integrated circuit does not need to operate, the clamping circuit is ON to clamp the base potential of the fourth transistor so as to reduce the power consumption of the semiconductor integrate circuit.
    Type: Grant
    Filed: May 5, 1988
    Date of Patent: January 30, 1990
    Assignees: Fujitsu Limited, Fujitsu VLSI Limited
    Inventors: Shinji Saito, Kazuyuki Nonaka, Hideji Sumi, Takehiro Akiyama
  • Patent number: 4890018
    Abstract: A bipolar-complementary metal oxide semiconductor circuit includes a p-channel MOS transistor, and an n-channel MOS transistor, first and second bipolar transistors. A base of the first bipolar transistor is connected to a negative power source through the n-channel MOS transistor. A diode is connected to the base and emitter of the first bipolar transistor. The diode functions to prevent a reverse-biased voltage exceeding a base-emitter breakdown voltage from being applied between the base and emitter of the first bipolar transistor.
    Type: Grant
    Filed: November 10, 1988
    Date of Patent: December 26, 1989
    Assignees: Fujitsu Limited, Fujitsu VLSI Limited
    Inventors: Isao Fukushi, Takahisa Muroi
  • Patent number: 4882712
    Abstract: A synchronous semiconductor memory device has a noise preventing part for preventing a noise from being transmitted to a memory cell array, where the noise is caused by a change in a write data.
    Type: Grant
    Filed: September 26, 1988
    Date of Patent: November 21, 1989
    Assignees: Fujitsu Limited, Fujitsu VLSI Limited
    Inventors: Chikai Ohno, Michiyuki Hirata
  • Patent number: 4870617
    Abstract: A semiconductor memory device comprises a plurality of reset circuits connected to a data bus pair at different locations. Before each read operation, the reset circuits reset the data bus pair to a predetermined reset voltage. The resetting of the data bus pair is virtually unaffected by the distributed resistances and parasitic capacitances of the data bus pair, since the resetting is carried out at a plurality of locations on the data bus pair.
    Type: Grant
    Filed: September 16, 1987
    Date of Patent: September 26, 1989
    Assignees: Fujitsu Limited, Fujitsu Vlsi Limited
    Inventors: Masao Nakano, Tsuyoshi Ohira, Hirohiko Mochizuki, Yukinori Kodama, Hidenori Nomura
  • Patent number: 4835590
    Abstract: A semiconductor memory device using a junction short type programmable element comprises an epitaxial layer formed on a semiconductor substrate, the epitaxial layer having an opposite conductive type to that of the semiconductor substrate, the epitaxial layer being a collector region; a base region having the same conductive type as the substrate formed in the epitaxial layer; a first emitter region having an opposite conductive type to that of the base region, formed in the base region; an insulating isolation region, formed in said epitaxial layer and around the base region; a second emitter region having a higher impurity concentration than that of the first emitter region and the same conductive type as the of the first emitter region, formed in the first emitter region in such a manner that the second emitter region penetrate the first emitter region upward and downward and extends to the interior of the base region (14) so that a writing current flows concentratedly at the second emitter region.
    Type: Grant
    Filed: March 10, 1987
    Date of Patent: May 30, 1989
    Assignees: Fujitsu Limited, Fujitsu VLSI Limited
    Inventors: Kouji Ueno, Takamitsu Naito, Yoshitaka Nakajima
  • Patent number: 4821232
    Abstract: A semiconductor memory device comprises a memory cell array comprising a plurality of memory cells arranged in a matrix arrangement, a sense amplifier, operatively connected to the memory cell array, amplifying a signal read out from one of the memory cells and having a pair of output terminals for outputting a complementary signal, a pair of data buses for transferring the complementary signal, a transfer gate for connecting the pair of output terminals to the pair of data buses responsive to a read operation, a data output buffer connected to the pair of data buses for outputting an output signal, and a reset circuit for resetting the pair of data buses to a predetermined voltage before each read operation responsive to a reset clock signal.
    Type: Grant
    Filed: September 16, 1987
    Date of Patent: April 11, 1989
    Assignees: Fujitsu Limited, Fujitsu VLSI Limited
    Inventors: Masao Nakano, Tsuyoshi Ohira, Hirohiko Mochizuki, Yukinori Kodama, Hidenori Nomura
  • Patent number: 4807192
    Abstract: A memory device employing address multiplexing comprises a counter. An external address is initially set in the counter and a counter address value is incremented responsive to toggle of a column address strobe. The counted address value in the counter is supplied as an address signal directly to a column decoder or indirectly to the column decoder through an address buffer. The memory device may be provided with a switching logic circuit which switches the address bits in the counter depending on switching information so that it is possible to arbitrarily determine which address bits in the counter are to determine a nibble address.
    Type: Grant
    Filed: August 31, 1987
    Date of Patent: February 21, 1989
    Assignees: Fujitsu Limited, Fujitsu Vlsi Limited
    Inventors: Masao Nakano, Hirohiko Mochizuki, Tsuyoshi Ohira, Yukinori Kodama, Hidenori Nomura
  • Patent number: 4806795
    Abstract: A transfer gate circuit including a first MIS transistor which transmits an input signal supplied from an input side thereof to an output side thereof in accordance with a control signal supplied to a gate of the first MIS transistor; an inverter circuit connected between power supply lines which inverts the potential of the transmitted input signal; and an output level guarantee circuit comprising second and third MIS transistors which have conductivity type opposite to that of the first MIS transistor and are connected in series between one of the power supply lines and the output side, an output signal of the inverter circuit being supplied to a gate of the second MIS transistor, an inverted signal of the control signal supplied to the gate of the first MIS transistor being supplied to a gate of the third MIS transistor.
    Type: Grant
    Filed: September 16, 1987
    Date of Patent: February 21, 1989
    Assignees: Fujitsu Limited, Fujitsu Vlsi Limited
    Inventors: Masao Nakano, Tsuyoshi Ohira, Hidenori Nomura
  • Patent number: 4799197
    Abstract: A semiconductor memory device comprises a memory cell array comprising memory cells; a plurality of pairs of bit lines which are coupled to the memory cells and a data bus, each bit line being divided into at least two pairs of bit line parts; at least one sense amplifier provided between the pairs of bit line parts in each of the pairs of bit lines, for sensing a difference in potential between bit line parts in each pair, the sense amplifier being formed with complementary metal oxide semiconductor transistors; and at least a pair of transfer gates provided between a non-data bus side and a data bus side of the sense amplifier, the pair of transfer gates being held in an off-state when the sense amplifier is activated.
    Type: Grant
    Filed: September 1, 1987
    Date of Patent: January 17, 1989
    Assignees: Fujitsu Limited, Fujitsu VLSI Limited
    Inventors: Yukinori Kodama, Hirohiko Mochizuki, Masao Nakano, Tsuyoshi Ohira, Hidenori Nomura
  • Patent number: 4788583
    Abstract: A semiconductor device has such a construction that free tip ends of stage bars extending from a stage do not extend to side surfaces of a resin package, and the resin package is constituted by an inner resin package portion and an outer resin package portion. The free tip ends of the stage bars are located inside the outer resin package portion and are completely sealed. A method of producing the semiconductor device includes steps of providing wires for electrically connecting terminals of a semiconductor element which is mounted on the stage with corresponding leads and forming the inner resin package portion over the semiconductor element and its vicinity including portions of the leads and stage bars which are connected to the stage.
    Type: Grant
    Filed: July 24, 1987
    Date of Patent: November 29, 1988
    Assignees: Fujitsu Limited, Fujitsu Vlsi Limited
    Inventors: Toshimi Kawahara, Michio Sono, Hiroaki Hayashi
  • Patent number: 4675555
    Abstract: In a semiconductor device including a plurality of input signal pads (P.sub.0, . . . , P.sub.7); a plurality of emitter followers (Q.sub.01, . . . , Q.sub.71) are connected to the input signal pads (P.sub.0, . . . , P.sub.7); a plurality of input signal buffers (BUF.sub.0, . . . , BUF.sub.7) are connected to the emitter followers (Q.sub.01, . . . , Q.sub.71); and a plurality of constant current sources (I.sub.01, . . . , I.sub.71) are connected to the emitter followers (Q.sub.01, . . . , Q.sub.71). The emitter followers (Q.sub.01, . . . , Q.sub.71) are in proximity to the input signal pads (P.sub.0, . . . , P.sub.7), and the constant current sources (I.sub.0, . . . , I.sub.7) are in proximity to the emitter followers (Q.sub.01, . . . , Q.sub.71) . The current values of the constant current sources (I.sub.01, . . . , I.sub.71 ) are determined in accordance with the length of the corresponding connections between the emitter followers (Q.sub.01, . . . , Q.sub.71) and the input signal buffers (BUF.sub.0, . . .
    Type: Grant
    Filed: December 27, 1985
    Date of Patent: June 23, 1987
    Assignees: Fujitsu Limited, Fujitsu VLSI Limited
    Inventors: Yoshinori Okajima, Masaki Ohiwa