Abstract:
A data transfer apparatus is disclosed which has a first, a second, and a third pipeline processing circuits disposed in cascade connection. The first and the second pipeline processing circuits are each provided with an arbitrary signal processing circuit, a switch element for controlling the introduction of data into the signal processing circuit, and a switch control circuit for turning on the switch element on detecting completion of the transfer of data from the signal processing circuit to a pipeline processing circuit in the subsequent stage. The third pipeline processing circuit is provided with an output circuit and a switch element for introducing data transferred from the second pipeline processing circuit into the output circuit as synchronized with an external clock signal. Between the first and the second pipeline processing circuit, therefore, data can be transferred with a timing conforming to the timing of the operation of the signal processing circuit without being synchronized with an external clock signal. In the output circuit, data can be issued as synchronized with an external clock signal. Thus, a signal of a very high frequency can be selected as a clock signal for setting the timing of the whole of a system incorporating the data transfer apparatus therein.
Abstract:
A semiconductor memory having a plurality of banks, a first specify unit, and a second specify unit. The first specify unit is used to specify one of the banks by decoding a bank address signal contained in a row address signal. The second specify unit is used to specify one of the banks by decoding the bank address signal contained in the row address signal, according to bank status signals that indicate whether or not each of the banks is activated. Therefore, the semiconductor memory is used for different bank configurations. Namely, with this arrangement, the semiconductor memory is capable of serving as a memory having a smaller number of banks, to thereby improve convenience.
Abstract:
A semiconductor memory includes a plurality of cell blocks, a refresh control circuit which sequentially refreshes a plurality of the cell blocks, an access control circuit which accesses a plurality of the cell blocks, and an ECC circuit which is provided in a data path between the access control circuit and the plurality of cell blocks, so that the data which is input from and output to the access control circuit is converted to a predetermined bit converted data (so called code) by the ECC circuit and is stored in the plurality of cell blocks. Accordingly, when the access control circuit accesses the plurality of cell blocks, if the access cannot be carried out for specified cell block which is in a refresh state (that is, a correct data (code) cannot be written to or read from the cell block in a refresh state) the data in the access control circuit side can be reproduced as correct data by the ECC circuit. Therefore, viewed from the external, a predetermined access can be carried out without being affected by the refresh state.
Abstract:
A dynamic random access memory (DRAM) device is formed on a semiconductor substrate, the device having an array of memory cells which are divided in several sub-arrays. The device has memory blocks each containing one of the sub-arrays, a word decoder and column decoder. Each of the memory blocks is selected independently to perform an access operation and refresh operation. As long as different memory blocks are selected for the respective operations, both operations are performed in parallel, however, when the same memory block is selected for both operations, namely, double selection, a comparison circuit detects the double selection and gives priority to one of the operations. The operation selected thus, preferentially performed. Usually, the refresh operations is then performed. However, in order to decrease the "busy ratio" of the device, the access operation is performed preferentially. Further, a complicated operation for priority selection may be performed according to a predetermined schedule memorized in a priority providing means. In addition, a common word bus line is proposed for accessing each of the memory blocks, namely, each sub-arrays, in order to reduce the number of common word lines for realizing a further high packing denisty of the DRAM device. This common bus line is also applicable to other devices such as a static RAM.
Abstract:
A semiconductor integrated circuit including a memory unit for storing address information of a failed circuit portion and for replacing the failed circuit portion by a redundant circuit portion. The semiconductor integrated circuit provides a comparison unit for detecting coincidence between data read from the memory unit and a received input address. Data produced from the comparison by the comparison unit is delivered through an external connection terminal.
Abstract:
A semiconductor memory device with shift registers used for a video RAM, including a memory cell array, bit lines, and word lines, a pair of shift registers, and transfer gate circuits arranged between the bit lines and the shift registers. Each parallel data transfer circuit is provided between the shift registers for transferring parallel data between the shift registers, so that high-speed reading and writing of data for a CRT display is realized.
Abstract:
A device connected between first and second voltage feed lines includes an information storing circuit having a fuse for storing information by blowing or not blowing the fuse, a voltage level conversion circuit connected to at least one of the first and second voltage feed lines and outputting a voltage lower than a voltage between the first and second voltage feed lines to the information storing circuit, and a circuit connected between the first and second voltage feed lines, for outputting a detection signal in response to a voltage value at the fuse in the information storing circuit to which the voltage is applied from the voltage level conversion circuit and which voltage value is varied with the blown or unblown state of the fuse.In a normal operation, the voltage output from the voltage level conversion circuit can be set as low as possible to restrain electromigration caused at the vicinity of the blown portion of the fuse to which the voltage is applied, but higher than the threshold voltage of the information detection circuit.
Abstract:
A voltage converting circuit has an output MIS transistor which gives a low output impedance and outputs an intermediate level of power source voltage. The output level is set with a high accuracy through a voltage dividing ratio determined by an impedance element. This impedance element is connected with a compensating MIS transistor to compensate for variations of the gate threshold voltage caused by the manufacturing process.
Abstract:
A semiconductor memory device which has an error correcting circuit and employs a virtual two-dimensional matrix for correcting read data is provided. The device includes a redundant memory cell to replace a defective memory cell. When the selected memory cell has a previously determined hard error, the selected memory cell is replaced by the redundant memory cell. When the selected memory cell has a soft error or a hard error occuring after the determination of the previously determined hard error, the read data is corrected by the error correcting circuit.
Abstract:
A semiconductor memory device having a data inverting circuit for selectively inverting an input/outpt data of a sense amplifier in such a way that the charging states of respective memory cells connected to two bit lines in each bit line pair become equal for the same input/output data. A clamp circuit draws the potentials of all of the bit lines to a predetermined potential in response to a clear control signal, whereby the contents of all of the memory cells are cleared at the same time.