摘要:
A semiconductor memory device comprises a plurality or CAM cells. In a refreshing operation, data of "1" is applied to all of bit lines and inversion bit lines. In the CAM cells storing the data "1", writing of the data "1" onto the bit lines and the inversion bit lines is performed. Then, the data of "0" is applied to all of the bit lines and the inversion bit lines. In the CAM cells storing the data "0", writing of the data "0" onto the bit lines and the inversion bit lines is performed. In a partial writing operation, in the CAM cells to which writing is performed, a first control node is activated, thereby making it possible to write the CAM cells. In the rest of the CAM cells, the first control node is inactivated, thereby making it impossible to write the CAM cells.
摘要:
An encoding circuit shortens time required for a coincidence signal to be converted into an address code after selected and output sequentially according to a predetermined priority level when the coincidence signal is obtained from an associative memory. The circuit is provided with a contention arbitrating circuit for a lower subgroup and a contention arbitrating circuit for a higher subgroup. In the contention arbitrating circuit for a lower subgroup and the contention arbitrating circuit for higher subgroup, each coincidence signal simultaneously activates inhibiting signals whose priority levels are lower than the priority level of the coincidence signal. A lower half of coincidence signals are arranged in descending order in the contention arbitrating circuit for a lower subgroup and a higher half of coincidence signals are arranged in ascending order in the contention arbitrating circuit for a higher subgroup. The contention arbitrating circuit for a lower subgroup and the contention arbitrating circuit for a higher subgroup are arranged in a triangular array and a complementary triangular array, respectively.
摘要:
A data storing circuit including memory cells arranged in a plurality of rows and columns and flag cells corresponding to respective rows for storing flag information, the memory cells and the flag cell of the same row constituting one word, is provided. When a retrieval data is externally applied, the data included in the retrieval data is compared with the data of the memory cell, and the flag information stored in the retrieval data is compared with the flag stored in the flag cell. Respective results of comparison are output to a match line. Logical operation circuit carries out logical operation dependent on the result of comparison output to the match line, and writes the logical output to the flag cell of the data storing circuit.
摘要:
A bit line control circuit is disclosed for implementing a dynamic content addressable memory. The bit line control circuit includes a read circuit 12 and a first write circuit 13 connected to data line pairs DT, /DT, a sense amplifier 14, a bit line discharge circuit 15, a bit line charge circuit 16, a transfer gate circuit 17, and a second write circuit 18. The bit line control circuit is connected to a CAM cell array through bit lines BLa, /BLa. Various operations such as write, read, refresh and match detection and the like necessary in the dynamic associative memory can be implemented under simple timing control by a simple circuit configuration.
摘要:
A semiconductor integrated circuit device including a semiconductor substrate having a main surface; a first conductive region formed on the main surface; a second conductive region formed on the main surface, spaced apart from the first conductive region and to be electrically connected to the first conductive region; and a capacitor having a storage node connecting the first and second conductive regions. The storage node serves to connect the first and second conductive regions and simultaneously stores charges. In other aspects of the invention, there are provided a memory cell having a structure described above, and a method of manufacturing the above-described semiconductor integrated circuit device.
摘要:
A memory module is provided with switch groups (SD0a to SD7a) in corresponding relation to data lines (DQ0 to DQ63) connected to memory devices (MD0 to MD7). The switch groups (SD0a to SD7a) connect all of the data lines (DQ0 to DQ63) to a portion external to the memory module (MMa) in a memory operation, and connect all of the data lines (DQ0 to DQ63) to inputs of an exclusive NOR circuit (EXa) after common 1-bit data is written into the memory devices (MD0 to MD7) in a testing operation. A malfunction of the memory devices (MD0 to MD7) is detected using an output signal (TMSa) from the exclusive NOR circuit (EXa). The memory module is accomplished which allows an inexpensive tester to conduct an electrical assembly check and a simple data write and read operation test upon the memory devices, which includes a small number of I/O pins for the check and test, and which does not deteriorate data input/output characteristics of the memory devices.
摘要:
Columns included in a sub-block are divided into first and second groups. If a defective memory cell column is present in the first group, an address comparison circuit activates a signal to select a redundant memory cell column, then selection prohibiting signal attains an "L" level based on information programmed in a programming circuit, a selection of a column in the first group is prohibited, and a redundant memory cell column selection signal is activated. Meanwhile, a normal selecting operation is performed to the second column group.
摘要:
A memory cell array of a dynamic semiconductor memory device is divided into a plurality of memory cell blocks. A block selecting circuit selects and refreshes larger number of memory cell blocks in refreshing mode than the number of those selected during normal mode. Sense amplifiers in the memory cell blocks selected by the block selecting circuit are selectively driven with smaller driving force in refreshing mode than that in normal mode. More preferably the driving force is changed during the amplifying operation so as to achieve both the high sensitivity and the suppression of the peak value of the operational current.
摘要:
A boosting circuit is provided applicable in various semiconductor integrated circuits such as a word line boosting circuit in a semiconductor memory. Because a backgate electrode of a PMOS transistor connected between power supply potential and an output node is connected to the output node, the output node is precharged to the Vcc level during a boosting term. Therefore, the boosting condition by a MOS capacitor is alleviated in comparison with a conventional boosting circuit. Proper boosting operation can be carried out even at a lower level of a supplied power supply voltage. Therefore, operable margin of power supply voltage is enlarged.
摘要:
In a test mode, bit information of the same logic is written into a corresponding memory cell of each of subarray 5a-5d. Bit information written in respective memory cells is simultaneously read and supplied to exclusive-OR gates 12a-12d. Each of exclusive-OR gates logics of read bit information and an expected value data supplied as an input to an external input pin D.sub.IN to supply the test determination result as an output. The outputs of respective exclusive-OR gates 12a-12d are serially supplied, through transistors 18a-18d which are sequentially and selectively turned on by a shift register 15, to an external output pin D.sub.OUT.