摘要:
In a dynamic random access memory (DRAM), there is provided a refresh decision circuit which detects the external designation of a self refresh mode, in addition to a CAS before RAS refresh mode, by RAS and CAS signals. By detecting a time period of one cycle of the RAS, the self refresh mode is determined. As a result, the timing of change of the RAS signal is less restricted.
摘要:
A substrate bias potential generator for biasing a semiconductor substrate to a predetermined potential includes first and second substrate bias generating circuits which operate alternatively according to the potential of the substrate, whereby consumption of power in the substrate bias potential generator is reduced. The alternative operation of the bias generating circuits each activated by a pulse signal train is performed by using a first insulated gate transistor having a gate electrode connected to the semiconductor substrate, a second insulated gate transistor having a gate electrode for receiving the reference potential, an amplifier for differentially amplifying outputs of the first and second insulated gate transistors, an insulated gate transistor for charging an output of the amplifier to a predetermined potential when the amplifier is activated, and a circuit for transmitting the output of the differential amplifier to the first and second bias potential generating circuits. The differential amplifier is activated in response to an activation signal of a pulse train whereby an activation signal corresponding to the pulse train is transmitted to either substrate bias potential generating circuit.
摘要:
In a dynamic random access memory (DRAM), there is provided a refresh decision circuit which detects the external designation of a self refresh mode, in addition to a CAS before RAS refresh mode, by RAS and CAS signals. By detecting a time period of one cycle of the RAS, the self refresh mode is determined. As a result, the timing of change of the RAS signal is less restricted.
摘要:
A dynamic-type semiconductor memory device has a test mode of simultaneously carrying out functional testing on a plurality of bits of memory cells. In data writing in the test mode, data inverted from the write-in data is written in at least a 1-bit memory cell out of the plurality of bits of memory cells selected simultaneously, and the same data as the write-in data is written in the remaining memory cells. In data reading in the test mode, the data of those of the memory cells selected simultaneously, in which the inverted data is written are inverted and read, while the data of the remaining memory cells are read as they are. Logic processing is carried out on the read-out data of the plurality of bits, so that a logic value indicating acceptability of the semiconductor memory device is output, depending on a result of determination as to whether or not the read-out data is the same as each other.
摘要:
A memory cell array (10) is divided into four blocks. Each block comprises a memory cell array block (10aand a memory cell array block (10b). A sense amplifier block (20) is disposed between the memory cell array blocks (10a) and (10b). Each sense amplifier block (20) is connected to the memory cell array blocks (10a) and (10b) via switching circuits (80a, 80b), respectively. Four decoders (51) are provided corresponding to the four blocks. The four decoders (51) are commonly provided with a driver (52) generating a high level driving signal. Each decoder (51) is responsive to an address signal for supplying a driving signal from the driver (52) to either one of the switching circuits (80a, 80b) and for applying a ground potential to the other one of the circuits. Accordingly, the sense amplifier block (20) is connected to either one of the memory cell array blocks (10a, 10b ).
摘要:
A dynamic semiconductor memory device is divided into a plurality of blocks. An operation of the semiconductor memory device is in either of a normal mode and a refresh mode, depending on the level of a refresh signal. In the normal mode, at an off time period, a potential on a bit line pair is equalized and a precharge potential is applied to the bit line pair. At the access time, equalizing of the potential on the bit line pair and supply of the precharge potential are stopped in a selected block and then, a word line driving signal is raised. On the other hand, in the refresh mode, at the off time period, the potential on the bit line pair is held at "H" and "L" levels by a sense amplifier, so that the potential on the bit line pair is not equalized and the precharge potential is not supplied. On this occasion, a precharge potential generating circuit is electrically disconnected from a power supply. At the time of refresh operation, the sense amplifier is rendered inactive in the selected block, so that the potential on the bit line pair is equalized and then, the word line driving signal is raised.
摘要:
A plurality of memory arrays (10a, 10b) are formed on a semiconductor chip (CH). A peripheral circuit (60) is arranged in the central portion of the plurality of memory arrays (10a, 10b). A plurality of pads (PD;p1.about.p18) are formed on both ends of the semiconductor chip (CH). The plurality of memory arrays (10a, 10b) are formed of predetermined layers (101.about.109). A plurality of interconnections (L) to be connected between the plurality of pads (PD;p1.about.p18) and the peripheral circuit (60) are provided to cross the plurality of memory arrays. The plurality of interconnections (L) are formed of layers (112;113) other than the predetermined ones.
摘要:
A dynamic random access memory with self-refresh function, which includes a substrate bias generator (100) adapted to be intermittently driven to apply a bias potential to a semiconductor substrate (15). This memory device comprises a circuit (91) for generating an internal refresh instruction signal (.phi..sub.S) in response to an external refresh instruction signal, a circuit (92, 93) which, in response to the internal refresh instruction signal, generates a refresh enable signal (.phi..sub.R) intermittently at a predetermined interval, a circuit (94, 95, 96, 98) which, in response to the refresh enable signal, refreshes data in the memory cells, and a circuit (99) which, in response to the internal refresh instruction signal and refresh enable signal, activates the substrate bias generator in the same cycle as the cycle of generation of the refresh enable signal and only for a time shorter than the cycle of generation of the refresh enable signal. The above construction contributes to a reduced power consumption in the dynamic random access memory.
摘要:
A dynamic random access memory having a self-refresh mode comprises a memory array partitioned into four groups in which control are respectively performed and a partial activation control circuit. The four groups in the memory array are alternately refreshed two by two in an operation under the self-refresh mode. As a result, each group in the memory array is refreshed at a time interval of two times a conventional refresh interval, so that the power consumption is decreased.
摘要:
A semiconductor memory device comprises eight memory arrays (b 10a, 10b) arranged in one column. A peripheral circuit (60) is arranged in the central portion of the eight memory arrays (10a, 10b), two column decoders (51, 52) being arranged with the peripheral circuit (60) interposed therebetween. Each of the eight memory arrays (10a, 10b) is provided with a row decoder (20). A plurality of first column selecting lines (CL1) are provided so as to cross the three memory arrays (10a, 10b) arranged on one side of the peripheral circuit (60) from the column decoder (51). In addition, a plurality of second column selecting lines (CL2) are provided so as to intersect with the three memory arrays (10a, 10b) arranged on the other side of the peripheral circuit (60) from the column decoder (52).