Abstract: A semiconductor memory device comprises an anti-fuse, a memory circuit including memory cells, and a peripheral circuit configured to access only an area of the memory circuit selected depending on a state of the anti-fuse.

Abstract: A duty detection circuit includes an integration circuit for receiving an RCLK signal and an FCLK signal that are internal clock signals generated by a DLL circuit, and generating voltage levels in accordance with the duty ratio of these internal clock signals; an amplifier for amplifying the output of the integration circuit; a latch circuit for latching the output of the amplifier; a control circuit for controlling the operation timings of each component; a bias circuit for feeding a BIAS signal to the integration circuit; and a frequency monitor circuit unit for monitoring the frequency of the clock signal. The frequency monitor circuit unit is a circuit component used when the power source is turned on, during resetting, and when other initial settings are performed, and detects the actual frequency of the clock signal and adjusts the amount of charging or discharging of the capacitors C1 through C4 in the integration circuit according to this actual frequency.

Abstract: A duty detection circuit includes an integration circuit for receiving an RCLK signal and an FCLK signal that are internal clock signals generated by a DLL circuit, and generating voltage levels in accordance with the duty ratio of these internal clock signals; an amplifier for amplifying the output of the integration circuit; a latch circuit for latching the output of the amplifier; a control circuit for controlling the operation timings of each component; a bias circuit for feeding a BIAS signal to the integration circuit; and a frequency monitor circuit unit for monitoring the frequency of the clock signal. The frequency monitor circuit unit is a circuit component used when the power source is turned on, during resetting, and when other initial settings are performed, and detects the actual frequency of the clock signal and adjusts the amount of charging or discharging of the capacitors C1 through C4 in the integration circuit according to this actual frequency.

Abstract: Provided is a semiconductor memory device in which it is possible to conduct a parallel test by comparison with an expected value after replacement with a redundant cell. A redundant circuit provided in correspondence with each of a plurality of redundant addresses includes a determination circuit for determining whether an access address has been replaced with a redundant cell, and a circuit for producing an activated output signal if a signal, which indicates that an area is using a redundant set, and a redundancy selection signal have both been activated.

Abstract: In a semiconductor memory having a plurality of memory banks that can be independently accessed, remedying bit registers that are substituted for defective memory cells are respectively provided for memory banks in a one-to-one relationship. Also, means for sharing the plurality of remedying bit registers in each memory bank is arranged.

Abstract: In a semiconductor memory having a plurality of memory banks that can be independently accessed, remedying bit registers that are substituted for defective memory cells are respectively provided for memory banks in a one-to-one relationship. Also, means for sharing the plurality of remedying bit registers in each memory bank is arranged.

Abstract: A testing device for a semiconductor storage device which suppresses the increase in the circuit size, provides for facilitated accommodation to a test with frequent changes in the test pattern, and which improves testability of the semiconductor storage device. A plural number of holding circuits (103) are provided holding write data for memory cells of a memory cell array (101-1). The write data from the holding circuits (103) are written in the memory cells of the selected address. A plural number of comparators (CCMPN) are supplied with data read out from the memory cells and with data held by the holding circuits as expectation data to compare the readout data and the expectation data. The non-inverted value or the inverted value of the write data held by the holding circuits (103) is output as the write data to the memory cells and as expectation data to the comparators (CCMPN) depending on the value of the inversion control signal (DIM).

Abstract: The clock delay circuit according to the present invention includes a delay circuit section, a selection circuit section, and jitter suppression elements. The delay circuit section provides a plurality of delay clock signals that are obtained by delaying a clock signal with a different delay amount. The selection circuit section selects and provides any one of a plurality of delay clock signals that are provided from the delay circuit section. The jitter suppression elements are connected in series between the delay circuit section and the selection circuit section. When jitters occur at the time of switching the delay clock signals at the selection circuit section, the jitter suppression elements serve to prevent the propagation of the jitters through the delay circuit section.

Abstract: During writing of fail addresses to address registers, when writing of a number of fail addresses that is greater than the number of antifuses that have been provided in advance is about to be executed, or when a storage process of a number of fail addresses that is greater than the number of antifuses that have been provided in advance is about to be executed, delivering as output an overflow signal indicating that the writing or storage operation cannot be executed and reporting to the outside that remedy of defects by antifuses is no longer possible.

Abstract: In a command generating circuit, operation mode signals (signals determining internal operations, such as ACTIVE, READ, WRITE, and PRECHARGE) are determined by decoding command signals /CS, /RAS, /CAS, and /WE. The operation mode signals and bank select signals (BS0, BS1, BS2, and BS3) are latched by internal clocks. Thereafter, a logical product (AND) of each of the latched operation mode signals and each of the latched bank select signals is calculated.

Abstract: A testing device for a semiconductor storage device suppresses the increase in the circuit size, provides for facilitated accommodation to a test with frequent changes in the test pattern, and improves testability of the semiconductor storage device. A plurality of holding circuits are provided holding write data for memory cells of a memory cell array. (Original) The write data from the holding circuits are written in the memory cells of the selected address. A plurality of comparators are supplied with data read out from the memory cells and with data held by the holding circuits as expectation data to compare the readout data and the expectation data. The non-inverted or inverted value of the write data held by the holding circuits is output as the write data to the memory cells and as expectation data to the comparators depending on the value of the inversion control signal.

Abstract: During writing of fail addresses to address registers, when writing of a number of fail addresses that is greater than the number of antifuses that have been provided in advance is about to be executed, or when a storage process of a number of fail addresses that is greater than the number of antifuses that have been provided in advance is about to be executed, delivering as output an overflow signal indicating that the writing or storage operation cannot be executed and reporting to the outside that remedy of defects by antifuses is no longer possible.

Abstract: In a semiconductor memory having a plurality of memory banks that can be independently accessed, remedying bit registers that are substituted for defective memory cells are respectively provided for memory banks in a one-to-one relationship. Also, means for sharing the plurality of remedying bit registers in each memory bank is arranged.

Abstract: The duty detection circuit (100) comprises an integration circuit (110) for receiving an RCLK signal and an FCLK signal that are internal clock signals generated by a DLL circuit, and generating voltage levels (DB signal and VREF signal) in accordance with the duty ratio of these internal clock signals; an amplifier (120) for amplifying the output of the integration circuit (110); a latch circuit (130) for latching the output of the amplifier (120); a control circuit (140) for controlling the operation timings of each component; a bias circuit (150) for feeding a BIAS signal to the integration circuit (110); and a frequency monitor circuit unit (160) for monitoring the frequency of the clock signal.

Abstract: The present invention relates to a semiconductor memory device operating synchronously with a clock signal. The memory device includes a circuit for converting an external command signal supplied via an external terminal into an internal command signal including latency and outputting a detection signal when a collision between the internal command signals occurs.

Abstract: A fuse circuit according to the present invention uses an electrically writable fuse circuit and comprises a first fuse unit provided with a first electrically writable fuse, and a second fuse unit provided with a second electrically writable fuse, and the state of logical add of the states of the first and second fuse units is used as the output of the electrically writable fuse circuit in the first and second fuse units. Reliability in writing in of the fuse can be improved by using such a fuse circuit for a redundancy decoder circuit or the like.

Abstract: A parallel data outputting circuit equipped with a data inversion function, comprises P number of data comparator means, P number of majority decision circuits, P number of inversion flag generating means and P number of data inversion circuits, these being activated in parallel in one cycle. In generating an inversion flag indicating whether or not the parallel data are to be inverted and output in the inverted state, inversion flags are calculated from outputs of the inversion flag generating means and the inversion flag generating means of a cycle directly previous to a current cycle.

Abstract: A slew rate controlling system for output data is provided which is capable of improving an output data window even when change in a potential difference between a first power supply (VDD) to be used for outputting and a second power supply (VDDQ) to be used internally occurs. The slew rate controlling system is achieved by using a VDD-VDDQ potential difference detecting circuit to detect a decrease in a potential difference between the first power supply (VDD) and the second power supply (VDDQ) and to produce a first signal with specified timing and to detect an increase in a potential difference between the first power supply (VDD) and the second power supply (VDDQ) and to produce a second signal and by using a slew rate controlling circuit to exert control, when the first signal is significant, to enlarge a transition speed in a fall of output data and to exert control, when the second signal is significant, to enlarge the transition speed in a rise of output data and to produce output data.

Abstract: A testing device for a semiconductor storage device which suppresses the increase in the circuit size, provides for facilitated accommodation to a test with frequent changes in the test pattern, and which improves testability of the semiconductor storage device. A plural number of holding circuits (103) are provided holding write data for memory cells of a memory cell array (101-1). The write data from the holding circuits (103) are written in the memory cells of the selected address. A plural number of comparators (CCMPN) are supplied with data read out from the memory cells and with data held by the holding circuits as expectation data to compare the readout data and the expectation data. The non-inverted value or the inverted value of the write data held by the holding circuits (103) is output as the write data to the memory cells and as expectation data to the comparators (CCMPN) depending on the value of the inversion control signal (DIM).

Abstract: A majority circuit for reduce a size thereof is provided. The majority circuit is composed of a D/A converter converting a plurality of binary signals to an analogue signal, a majority determining circuit responsive to said analogue signal to achieve a majority operation on said plurality of binary signals to produce a result signal representative of a result of said majority operation.