Mitsubishi Denki Kabushiki Kaisha

Renesas Technology Corp.

Advanced Memory International, Inc.

Yoshikazu Morooka

Hiroshi Miyamoto

Naoya Watanabe

Kiyohiro Furutani

Makoto Suwa

Shigeru Kikuda

Shigeru Mori

Yasunobu Nakase

Mitsuya Kinoshita

Tsutomu Yoshimura

Takeshi Hamamoto

Michihiro Yamada

Tadaaki Yamauchi

Koichiro Mashiko

Tadato Yamagata

Toshifumi Kobayashi

Brent Keeth

Troy A Manning

Kazutami Arimoto

Peter B Gillingham

Terry R Lee

Kevin J Ryan

David V James

Cormac Michael O'Connell

Harufusa Kondoh

Bruce Millar

Hiromi Notani

Masaru Haraguchi

Tokuya Osawa

Henry Stracovsky

Kei Hamade

Yuto Ikeda

Desi Rhoden

Donald N North

Hans A Wiggers

Hiroshi Kinoshita

Makiko Aoki

David B Gustavson

Jean Crepeau

A variable delay line receives and delays a data strobe signal transferred from a data source side in synchronization with a transfer data by a predetermined period, and produces a delayed data strobe signal and the non-delayed data strobe signal to a detector. The detector determines that a preamble period ends and effective data is transferred, when the delayed data strobe signal is at the L level at the time of rising of the non-delayed data strobe signal from the L level to the H level. According to a result of detection, an interface circuit unit takes in the transfer data and initializes a take-in address. The data strobe signal changes to a high-impedance state when a postamble ends. An influence of a glitch noise is avoided upon this change of the data strobe signal, and the data transfer can be executed fast and accurately.

Interface circuit

A semiconductor integrated circuit capable of determining a configuration of a plurality of elements included in a functional block is provided. The semiconductor integrated circuit includes a memory functional block with a variable storage capacity, a functional block, and a terminal group for testing. A plurality of sub blocks are formed in the memory functional block when a chip is formed. Each of the plurality of sub blocks includes a determination circuit having substantially the same structure and function. A signal is input to the determination circuit from the terminal group, and a signal output through the determination circuit is observed at the terminal group. This enables determination of the configuration (the number, positional relationship, or the like) of the sub blocks.

Semiconductor integrated circuit provided with determination circuit

A SLDRAM System is provided with a plurality of in-circuit, calibratable memory modules and a memory controller for issuing unicast and multicast command packets to the memory modules. Command packets are transmitted over a unidirectional command link that includes a complementary pair of command clock lines, a command FLAG line and a plurality of noncomplemented command bit lines. Each of the command clock lines, command bit lines and the FLAG line is a SLIO transmission line. Data transfer operations are carried out in response to the command packets over one or more bidirectional data links that each includes two complementary pairs of data clock lines, and a plurality of noncomplemented data bit lines. Each of the data clock lines and the data bit lines is a SLIO transmission line. Each SLIO transmission line is single-end terminated and preferably tapped into by way of stub resistors.

Memory system having synchronous-link DRAM (SLDRAM) devices and controller

A data input/output circuit includes an S/P data conversion circuit which converts serial data input to a data terminal into a parallel data and transmits the parallel data to write data lines, a P/S data conversion circuit which converts parallel data on read data lines to serial data and outputs the serial data to the data terminal, and an input/output test circuit placed between the write data lines and the read data lines. The input/output test circuit responds to an input/output test signal to directly transfer data on the write data lines respectively to the read data lines without passing them through a memory cell array.

Semiconductor memory device having high data input/output frequency and capable of efficiently testing circuit associated with data input/output

A circuit module includes a connector terminal ( A) provided on a front surface of a printed wiring board ( ) and connected to a data pin (DQ ) of a memory IC ( ) through an interconnect line ( ). A conductive connector terminal ( ) corresponds to the connector terminal ( ) and is provided on a back surface of the printed wiring board ( ). A through hole ( ) extends between part of the front surface of the printed wiring board ( ) where the connector terminal ( ) is formed and part of the back surface thereof where the conductive connector terminal ( ) is formed. A conductor fills the through hole ( ), thereby suppressing skews resulting from a difference in interconnect line length on the circuit module and decreasing a stub capacitance to achieve the reduction in power consumption.

Circuit module

Each SLDRAM tests a built in memory section in response to a test execution command supplied from a memory controller and sends a defective address to memory controller. Memory controller stores the defective address of each SLDRAM and accesses only to a normal address and does not access to the defective address. The rate of memory capacity decrease of a main memory can be suppressed compared with a conventional technique where an SLDRAM having a defective address is not accessed.

Semiconductor memory device connected to memory controller and memory system employing the same

Transistors (MP1 and MP2) supply a current (I.sub.0) for nodes (K and L), respectively. Transistors (MN10 and MN11) draw the same current from nodes (K and L), respectively. A parallel connection of serial connections (N1 and N2) draws a current (I.sub.1) from the node (K) only when an exclusive OR of clocks (S1 and S2) is 'H'. On the other hand, a parallel connection of serial connections (N3 and N4) draws a current (I.sub.1) from the node (L) only when the exclusive OR of clocks (S1 and S2) is 'L'. When the current (I.sub.1) is drawn from the node (K), the current (I.sub.1) flows out from the node (L) and when the current (I.sub.1) is drawn from the node (L), the current (I.sub.1) flows into the node (L). In the serial connections (N1 to N4), each of the clocks (S1 and S2) and their inverted signals (S1B and S2B) is applied to one of the gates of the transistors (MN1 to MN8) and therefore a uniform input load is obtained. With this configuration provided is a 90-degree phase shifter which achieves the uniform input load to improve a phase offset.

Ninety-degree phase shifter

In a synchronous semiconductor memory device in which an internal clock signal from an internal timing clock signal generating circuit is branched in the form of a tree by driver circuits and applied to output buffers and data are output in synchronization with the internal clock signal, the driver circuit of the first stage is constituted by an NAND gate and an inverter. When output is to be temporarily stopped, an enabling signal is set to 'L' level, so that the NAND gate is closed, output of the clock signal to each driver circuit is stopped, and thus power consumption is reduced.

Synchronous semiconductor memory device employing temporary data output

Provided is a DLL circuit that can execute a precise delay synchronization operation without increasing the variable delay time range of a delay line. The DLL circuit comprises a phase comparator (3), a charge pump (6), an LPF (8) and a delay line (9), and operates to match phases of an input signal (CLKIN) and a feedback signal (FBCLK). The phase comparator (3) always outputs a phase comparison result that causes a delay time of the delay line (9) to increase, at the time of initial operation after a reset operation. The LPF (8) outputs a delay adjusting signal (S8) indicating that a delay time due to the delay line (9) becomes the minimum, in executing a reset.

Delay locked loop circuit

When an external RAS and external CAS are input to a RAS buffer and a CAS buffer, an internal RAS and an internal CAS are generated. The internal RAS is input to a clock generating circuit and a CBR mode determination circuit and the internal CAS is input to the CBR mode determination circuit. The clock generating circuit outputs a pump clock to first and second WL pumps upon input of internal RAS, and the first WL pump supplies charge to a Vpp power supply. If CAS is input prior to RAS during refresh operation, CBR mode determination circuit inputs a CBR mode signal to the second WL pump which supplies charge to Vpp power supply together with the first WL pump when the pump clock and the CBR mode signal is input thereto.

Semiconductor memory device having controllable supplying capability of

A voltage controlled delay circuit having the same structure, except for a loop, as a voltage controlled oscillator included in a PLL circuit which in turn generates an internal clock signal from an external clock signal is controlled by a control voltage from the PLL circuit, and the delay output of the voltage controlled delay circuit is selected by a selection circuit in accordance with the output signal of a vernier-adjusting counter in order to generate a read clock signal. Therefore, a vernier for optimizing data input timing in a controller can be realized which always has a constant delay amount regardless of a change in operating environment.

Clock-synchronous type semiconductor memory device capable of outputting

A memory system includes a data bus which is folded, a clock signal line extending in parallel with the data bus for transferring a clock signal, memories connected to the data bus and the clock signal line, and memories controller for controlling the memories, wherein the memory controller generates a clock signal to supply it to one end of the clock signal line, and is responsive to a clock signal input from another end of the clock signal line to receive data output from the memory from one end of the data bus.

Memory system capable of reducing timing skew between clock signal and

In a memory cell array, data lines are formed into a hierarchical arrangement of sub data lines provided for every block and a main data line common to each block, and a sub data line selected by a column address among sub data lines belonging a block which are simultaneously selected by a row address is connected to a bit line. Accordingly, the sub data line length is reduced, which reduces floating capacitance, reading and writing operations can be conducted at a high speed, and sub data lines can be selectively operated. In addition, power required for charging the sub data lines can be reduced, and entire power consumption by the semiconductor memory device can be reduced as well.

Semiconductor memory device permitting high speed data transfer and high

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Hyogo, Japan

Yoshikazu Morooka