Abstract: First and second pre-processing flip-flops latch a command/address signal inputted to a register by a clock having a frequency of ½ of an external clock signal and an inverse clock thereof. Thus, the command/address signal is decomprossed to a set of signals which temporarily has two times. For example, one of the set of signals has only data contents of an odd-th command/address signal, and the other has only data contents of an even-th command/address signal. Since the set of signals has twice periods of the command/address signal, first and second post-processing flip-flop can latch signals in accordance with an internal clock signal generated by a delay locked loop circuit in a state in which a set-up time and a hold time are sufficiently assured.

Abstract: A memory module comprises a stab resistor between a pin and one end of a bus. A plurality of memory chips is connected to the bus between both ends thereof. A terminating resistor is connected to the other end of the bus.

Abstract: A memory module is provided with a resistor serving as an impedance adjuster which is connected directly or indirectly to an output terminal of an output transistor of a C/A register. The resistor adjusts the output impedance of the C/A register viewed from an input terminal of a C/A bus in such a manner that the output impedance becomes substantially constant within an operating voltage range of an internal signal output from the C/A register. The memory module is further provided with a capacitor serving as a rise time/fall time adjuster which adjusts rise time and fall time of the internal signal to specific values such that satisfactory waveforms are obtained.

Abstract: Disclosed are a memory command address system and a memory module that can be operated not only for 266 MHzCLK but also for 200 MHzCLK, in which clock timings in the input sections of a PLL, a register, and a DRAM are matched to one another, a DLL (delay locked loop) is provided in the register, the output timing of CA signal from the register is controlled so that the setup time margin and the hold time margin of the CA signal with respect to the clock signal with the additional latency in the DRAM=1.5 or 2.0 are equated to each other, such that clock operation of 266 MHz, for example, is made possible. If both 266 MHz and 200 MHz are used, by taking account of the timing budget, control is made for retarding the timing of the CA signal input to the flip-flop which receives an internal clock signal (intCLK) supplied to the flip-flop for determining the CA signal output timing from the register.

Abstract: A memory module of the unbuffered type with ECC function is employed. Configuration of an internal C/A bus is set to a single T-branch topology. An output impedance of a chipset is maintained substantially constant. A capacitor for cutting high-frequency components of a C/A signal is added on a C/A bus.

Abstract: A memory module is provided with a resistor serving as an impedance adjuster which is connected directly or indirectly to an output terminal of an output transistor of a C/A register. The resistor adjusts the output impedance of the C/A register viewed from an input terminal of a C/A bus in such a manner that the output impedance becomes substantially constant within an operating voltage range of an internal signal output from the C/A register. The memory module is further provided with a capacitor serving as a rise time/fall time adjuster which adjusts rise time and fall time of the internal signal to specific values such that satisfactory waveforms are obtained.

Abstract: First and second pre-processing flip-flops latch a command/address signal inputted to a register by a clock having a frequency of 1/2 of an external clock signal and an inverse clock thereof. Thus, the command/address signal is decomprossed to a set of singals which temporarily has two times. For example, one of the set of signals has only data contents of an odd-th command/address signal, and the other has only data contents of an even-th command/address signal. Since the set of signals has twice periods of the command/address signal, first and second post-processing flip-flop can latch signals in accordance with an internal clock signal generated by a delay locked loop circuit in a state in which a set-up time and a hold time are sufficiently assured.

Abstract: A semiconductor device for testing highly integrated semiconductor devices in a compression mode by using a simple circuit and a specific physical pattern without using address data. The semiconductor device contains memory cell arrays and a device for selecting a test pattern input terminal which selects where a test pattern is to be input from among plural lines selected from bit lines and word lines, and a further device for generating a physical pattern which is constructed so that certain data is inputted in the lines selected to receive the test pattern, and so that the data is simultaneously outputted to data buses connected to plural lines other than the selected lines.

Abstract: A maximum value of the number of mounted memory devices is assumed, and a value of an external delay replica is fixed and set. A desired frequency band is divided into a plurality of sub-frequency bands, and delay times of an output buffer and an internal delay replica are switched and used every sub-frequency band, thereby setting an actual maximum value and an actual minimum value to the internal delay replica. A selecting pin can select the delay time in the internal delay replica. Thus, it is possible to sufficiently ensure a set-up time and a hold time of an internal clock signal generated by a delay locked loop circuit in the latch operation in a register within a desired frequency band and with a permittable number of memory devices, irrespective of the frequency level and the number of mounted memory devices.

Abstract: The present invention provides a circuitry for supplying data from a write input/output line pair to a digit line pair for writing the data into memory cells. The circuitry comprises: a balancing device for balancing in voltage level between the write input/output line pair by making a connection of the write input/output line pair; and a controller connected to the balancing device for controlling balancing operations of the balancing device.

Abstract: The present invention provides a circuitry for supplying data from a write input/output line pair to a digit line pair for writing the data into memory cells. The circuitry comprises: a balancing device for balancing in voltage level between the write input/output line pair by making a connection of the write input/output line pair; and a controller connected to the balancing device for controlling balancing operations of the balancing device.