Abstract:
A read register and a data transfer circuit are provided to implement two separate data transfer paths with respect to a preamplifier, for alternately transferring data through these two paths. Thus, the data can be transferred with no data collision in each clock cycle. The data are transferred at a high speed every clock cycle regardless of the bank number and the CAS latency in a multi-bank synchronous memory device.
Abstract:
A reset signal generating circuit in a synchronous semiconductor memory device outputs a reset signal ZPOR1 in response to a power on reset signal ZPOR generated immediately after power on and an initialize command (for example, a precharge command) executed for initialization after power on. A test mode register included in a mode setting circuit receives as a reset signal, the reset signal ZPOR1. Consequently, a test mode signal output attains to an NOP state, or output of the test mode signal is stopped.
Abstract:
A bare chip is provided with a pad for activation/deactivation control to which a deactivation control signal for converting a bare chip that has been detected as being defective into the deactivated condition is inputted. When a deactivation control signal is inputted to the pad for activation/deactivation control, internal circuit prevent a signal that has been inputted from the pad for data input/output control from being inputted to an internal circuit located further inside than the input buffer circuit. Thereby, the bare chip that has been detected as being defective can be converted to the deactivated condition. As a result, a semiconductor memory module can be obtained that can be repaired by newly mounting a good function chip without allowing the bare chip that has been detected as being defective to interfere with the functions of the semiconductor memory module.
Abstract:
In an output stage, an n-FET and a p-FET are connected in series, which is interposed between a power supply line and a ground. A first serial connection circuit generates a gate potential of the n-FET, and a second serial connection circuit generates a gate potential of the p-FET. The first and the second serial connection circuits are connected in parallel to each other, each of which has its one end connected to the power supply line through a resistor, and its other end connected to the ground through a resistor. As a result, even if a resistance value of the resistor is small, currents to be consumed can be reduced.
Abstract:
A first transfer circuit includes pipeline circuits having different number of stages, and switch circuits that exclusively supply the pipeline circuits with first and second read data. A second transfer circuit includes pipeline circuits having different number of stages, and switch circuits that exclusively supply the pipeline circuits with third and fourth read data. Outputs of the first and second transfer circuits are sequentially output from a multiplex circuit. When a first operation mode is selected, all the pipeline circuits are activated. When a second operation mode is selected, one of the pipeline circuits in the first transfer circuit and one of the pipeline circuits in the second transfer circuit are activated, whereas the others of the pipeline circuits are inactivated.
Abstract:
To provide a semiconductor memory device including a mode register in which a mode signal is set, a data amplifier that amplifies read data read from a memory cell array, a data bus onto which the read data amplified by the data amplifier is transmitted, a data input/output circuit that outputs a signal on the data bus to outside, and a mode signal output circuit that outputs the mode signal set in the mode register onto the data bus. Because the mode signal is not caused to interrupt halfway along the data input/output circuit, but supplied onto the data bus that connects the data amplifier to the data input/output circuit, no collision of the read data with the mode signal occurs in the data input/output circuit.
Abstract:
A dynamic type semiconductor memory device includes a plurality of data input/output nodes, a plurality of /CAS buffers for generating column address strobe signals corresponding to each of said input/output nodes, and an input node carrying out only data input. A switching signal generation circuit generates first and second switching signals indicating data input/output control modes. Memory cells corresponding in number to the data input/output nodes are selected simultaneously from a memory cell array. In operation of control mode A, data input/output is effected using an input node and one data input/ouput node. In the case of control mode B, data writing/reading is effected via a plurality of data input/output nodes according to one column address strobe signal. In the case of control mode C, data input/output is carried out individually for each input/output node according to a plurality of column address strobe signals. Modes A, B and C can be realized in one DRAM. Particularly, in mode C controlling data input/output according to respective column address strobe signals, writing/reading of unnecessary data bits can be prevented to reduce power consumption and prevent erroneous parity bit writing.
Abstract:
To provide a semiconductor memory device including a mode register in which a mode signal is set, a data amplifier that amplifies read data read from a memory cell array, a data bus onto which the read data amplified by the data amplifier is transmitted, a data input/output circuit that outputs a signal on the data bus to outside, and a mode signal output circuit that outputs the mode signal set in the mode register onto the data bus. Because the mode signal is not caused to interrupt halfway along the data input/output circuit, but supplied onto the data bus that connects the data amplifier to the data input/output circuit, no collision of the read data with the mode signal occurs in the data input/output circuit.
Abstract:
A conventional semiconductor memory device may be in need of a special refresh sequence if it is desired to reduce the current consumption in connection with a refresh operation. With this in view, there is disclosed a semiconductor memory device 1 that has a recording area 30 formed by a plurality of memory banks 31 to 3n. The refreshing operation for this semiconductor memory device 1 may be performed on the memory bank basis. The semiconductor memory device 1 includes refresh control circuits 21 to 2n and holding circuits 11 to 1n in association individually with the memory banks 31 to 3n. The holding circuits 11 to 1n are set when data has been written in associated ones of the memory banks 31 to 3n following resetting of the semiconductor memory device. The refresh control circuits 21 to 2n set the associated memory banks 31 to 3n to a refresh enabling state in case the associated holding circuits 11 to 1n are in a set state (FIG. 1).
Abstract:
In a semiconductor memory device including a plurality of memory chips, the plurality of memory chips are divided into first and second groups that are operated in parallel with each other at the time of a data read. Timings of activating sense amplifiers belonging to the first and second groups are made different from each other. Accordingly, the maximum value of peak current generated when the sense amplifiers are activated at the time of a data read is reduced by half in the semiconductor memory device as a whole. As the peak current is suppressed, the data reading operation can be executed stably.