摘要:
In a semiconductor memory device, with respect to low voltage application, technique of controlling a gate voltage of a shared MOS transistor increasing sense speed and increasing data read speed by preventing data inversion caused by noise and reducing bit line capacitance during sensing is provided. By a shared MOS transistor gate voltage control circuit connecting a sense amplifier and a memory cell array, a shared MOS transistor gate voltage (SHR) is lowered in two stages and bit line capacitance to be amplified is reduced taking noise during the sensing into consideration so that the sense speed is increased. Therefore, a timing of activating a column selection signal can be hastened and as a result, data read time can be reduced.
摘要:
The semiconductor memory device according to the invention is provided with a first delay circuit block that generates a timing signal of a circuit block to be operated in column cycle time determined by an external input command cycle and a second delay circuit block the whole delay of which is controlled to be a difference between access time determined by an external clock and the latency and column cycle time. These delay circuit blocks are controlled so that the delay of each delay circuit is a suitable value in accordance with column latency and an operating frequency, and each delay is controlled corresponding to dispersion in a process and operating voltage and a change of operating temperature.
摘要:
The semiconductor memory device according to the invention is provided with a first delay circuit block that generates a timing signal of a circuit block to be operated in column cycle time determined by an external input command cycle and a second delay circuit block the whole delay of which is controlled to be a difference between access time determined by an external clock and the latency and column cycle time. These delay circuit blocks are controlled so that the delay of each delay circuit is a suitable value in accordance with column latency and an operating frequency, and each delay is controlled corresponding to dispersion in a process and operating voltage and a change of operating temperature.
摘要:
In a semiconductor memory device, with respect to low voltage application, technique of controlling a gate voltage of a shared MOS transistor increasing sense speed and increasing data read speed by preventing data inversion caused by noise and reducing bit line capacitance during sensing is provided. By a shared MOS transistor gate voltage control circuit connecting a sense amplifier and a memory cell array, a shared MOS transistor gate voltage (SHR) is lowered in two stages and bit line capacitance to be amplified is reduced taking noise during the sensing into consideration so that the sense speed is increased. Therefore, a timing of activating a column selection signal can be hastened and as a result, data read time can be reduced.
摘要:
Disclosed is a semiconductor device including a first clock generator that generates a first clock signal having a first period from an input clock signal, a second clock generator that generates a second clock signal having a second period from the input clock signal, and a timing generator that receives the first clock signal, the second clock signal, an activation signal from a command decoder and a selection signal for selecting the delay time from a timing register to produce a timing signal delayed as from activation of the activation signal by a delay equal to a sum of a time equal to a preset number m prescribed by the selection signal times the first period and a time equal to another preset number n prescribed by the selection signal times the second period. The timing register holds the values of m and n. These values are set in the timing register in an initialization sequence at the time of a mode register set command. In the operating states, the timing signals are output from the timing generator at a desired timing based on the information stored in the timing register (FIG. 6).
摘要:
A semiconductor memory device having high integration, low power consumption and high operation speed. The memory device includes a sense amplifier circuit having plural pull-down circuits and a pull-up circuit. A transistor constituting one of the plural pull-down circuits has a larger constant than that of a transistor constituting the other pull-down circuits, for example, a channel length and a channel width. The pull-down circuit having the larger constant transistor is activated earlier than the other pull-down circuits and the pull-up circuit, which are activated to conduct reading. The data line and the earlier driven pull-down circuit are connected by an NMOS transistor and the NMOS transistor is activated or inactivated to control the activation or inactivation of the pull-down circuit.
摘要:
A substrate voltage control technique that prevents the operating speed from being decreased and suppresses a leakage current due to a lower threshold voltage with respect to a low voltage use. Since a center value of the threshold voltages is detected by plural replica MOS transistors, and a substrate voltage is controlled to control a center value of the threshold voltages, thereby making it possible to satisfy a lower limit of the operating speed and an upper limit of a leakage current of the entire chip. On the other hand, the substrate voltage is dynamically controlled during the operation of the chip, thereby making it possible to decrease the center value of the threshold voltages when the chip operates to improve the speed, and to increase the center value of the threshold voltages after the operation of the chip to reduce the leakage current of the entire chip.
摘要:
A substrate voltage control technique that prevents the operating speed from being decreased and suppresses a leakage current due to a lower threshold voltage with respect to a low voltage use. Since a center value of the threshold voltages is detected by plural replica MOS transistors, and a substrate voltage is controlled to control a center value of the threshold voltages, thereby making it possible to satisfy a lower limit of the operating speed and an upper limit of a leakage current of the entire chip. On the other hand, the substrate voltage is dynamically controlled during the operation of the chip, thereby making it possible to decrease the center value of the threshold voltages when the chip operates to improve the speed, and to increase the center value of the threshold voltages after the operation of the chip to reduce the leakage current of the entire chip.
摘要:
Disclosed is a timing control circuit that receives a first clock having a period T1, a group of second clocks of L different phases spaced apart from each other at substantially equal intervals and selection signals m, n supplied thereto and generates a fine timing signal delayed from the rising edge of the first clock signal by a delay td of approximately td=m·T1+n·(T2/L). The timing control circuit includes a coarse delay circuit and a fine delay circuit. The coarse delay circuit includes a counter for counting a rising edge of the first clock signal after an activate signal is activated and generates a coarse timing signal whose amount of delay from the first clock signal is approximately m·T1. The fine delay circuit comprises L-number of multiphase clock control delay circuits disposed in parallel, delays by n·T2/L the timing of sampling of the coarse timing signal by respective clocks of the group of L-phase second clocks, and takes the OR among the resulting delayed pulses to thereby produce the fine timing signal.
摘要:
A semiconductor memory device having high integration, low power consumption and high operation speed. The memory device includes a sense amplifier circuit having plural pull-down circuits and a pull-up circuit. A transistor constituting one of the plural pull-down circuits has a larger constant than that of a transistor constituting the other pull-down circuits, for example, a channel length and a channel width. The pull-down circuit having the larger constant transistor is activated earlier than the other pull-down circuits and the pull-up circuit, which are activated to conduct reading. The data line and the earlier driven pull-down circuit are connected by an NMOS transistor and the NMOS transistor is activated or inactivated to control the activation or inactivation of the pull-down circuit.