Abstract: A semiconductor memory device configured to share a local I/O line is described herein. The device includes: a memory cell array including a plurality of memory cells; a plurality of bit line sense amplifiers configured to sense and to amplify data stored in the plurality of memory cells; a plurality of bit lines configured to transmit transmitting the data stored in the plurality of memory cells to the plurality of bit line sense amplifiers, respectively; a plurality of bit line dividing circuits configured to selectively divide the plurality of bit lines; and a plurality of column selecting circuits configured to sequentially transmit the data amplified by the plurality of bit line sense amplifiers to corresponding I/O lines.

Abstract: A DRAM with a general interleaving scheme for data input/output uses a normal bank structure. The DRAM provides a high-performance without consideration of a data access pattern. In order to implement the high-performance, the DRAM includes a plurality of normal banks, at least one cache bank, which has the same data access scheme with the normal banks, for selectively storing data with a normal bank selected at a read mode and a controller for controlling the access to the cache bank and the selected normal bank when continuous read commands are occurred to the selected normal bank.

Abstract: A semiconductor memory device and a method for testing the same which optimizes operation conditions by detecting a test cell that may easily fail in a test among the memory cells passing a burn-in test, and detecting the worst operation conditions by performing the test on the test cell. The device and method reduce power consumption in a refresh or active operation. According to the device and method set forth, a test unit tests a test cell, controls operation conditions of the semiconductor memory device according to the test result, and outputs the operation conditions. A driving unit drives the semiconductor memory device using the operation conditions controlled by the test unit.

Abstract: A clock synchronization device divides a digital-to-analog converting unit into main and sub digital-to-analog converters and operates both main and sub digital-to-analog converting units if an output voltage of the digital-to-analog converting unit is lower than a reference voltage based on a voltage obtained when the delay rate of a variable delay line VDL is sharply increased or operates only the main digital-to-analog converting unit if the output voltage of the digital-to-analog converting unit is higher than the reference voltage. As a result, the clock synchronization device can make the output voltage of the digital-to-analog converting unit be linear with respect to a digital code, thereby improving a jitter property in a band with a very large gain of the variable delay line.

Abstract: A clock synchronization device divides a digital-to-analog converting unit into main and sub digital-to-analog converters and operates both main and sub digital-to-analog converting units if an output voltage of the digital-to-analog converting unit is lower than a reference voltage based on a voltage obtained when the delay rate of a variable delay line VDL is sharply increased or operates only the main digital-to-analog converting unit if the output voltage of the digital-to-analog converting unit is higher than the reference voltage. As a result, the clock synchronization device can make the output voltage of the digital-to-analog converting unit be linear with respect to a digital code, thereby improving a jitter property in a band with a very large gain of the variable delay line.

Abstract: A delay circuit of a clock synchronization device that includes an operational amplifier for setting the level of a current control voltage according to a voltage difference between a regulation voltage and a reference voltage. A number of unit delay cells connected in series are included, each having a delay time set according to a resistance control voltage and the current control voltage. Also, a variable resistance unit is included having a resistance value adjusted according to the resistance control voltage, where the variable resistance unit includes a cross coupled adjustment device that outputs signals to a next unit delay cell. The delay cells are controlled by using the operational amplifier and a replica cell to have a wide delay range. As a result, the working range can be set wide, jitters may be reduced and the chip size may also be reduced.

Abstract: A semiconductor memory device and a method for testing the same is disclosed. The device and method can optimize operation conditions by detecting a test cell that may easily fail in a test among the memory cells passing a burn-in test, and detecting the worst operation conditions by performing the test on the test cell. The device and method reduce power consumption in a refresh or active operation. According to the disclosed device and method, a test unit tests a test cell, controls operation conditions of the semiconductor memory device according to the test result, and outputs the operation conditions. A driving unit drives the semiconductor memory device using the operation conditions controlled by the test unit.

Abstract: A semiconductor memory device with a sense amplifier of the present invention reduces an offset voltage between input and output terminals of the sense amplifier to improve sensing sensitivity, whereby improving cell density of the device as well as achieving a stable operation in low voltage. For the purpose of achieving the foregoing objects, the semiconductor memory device with the sense amplifier includes a plurality of switch means for sequentially turning an amplifying method of the sense amplifier to rapidly sense and sufficiently amplify the data loaded on a bit line in response to a plurality of switch control signals.

Abstract: A semiconductor memory device with a sense amplifier of the present invention reduces an offset voltage between input and output terminals of the sense amplifier to improve sensing sensitivity, whereby improving cell density of the device as well as achieving a stable operation in low voltage. For the purpose of achieving the foregoing objects, the semiconductor memory device with the sense amplifier includes a plurality of switch means for sequentially turning an amplifying method of the sense amplifier to rapidly sense and sufficiently amplify the data loaded on a bit line in response to a plurality of switch control signals.