摘要:
A synchronous dynamic random access memory capable of accessing data in a memory cell array therein in synchronism with a system clock from an external system such as a central processing unit (CPU). The synchronous DRAM receives an external clock and includes a plurality of memory banks each including a plurality of memory cells and operable in either an active cycle or a precharge cycle, a circuit for receiving a row address strobe signal and latching a logic level of the row address strobe signal in response to the clock, an address input circuit for receiving an externally generated address selecting one of the memory banks, and a circuit for receiving the latched logic level and the address from the address input circuit and for outputting an activation signal to the memory bank selected by the address and an inactivation signals to unselected memory banks when the latched logic level is a first logic level, so that the selected memory bank responsive to the activation signal operates in the active cycle while the unselected memory banks responsive to the inactivation signals operate in the precharge cycle.
摘要:
A synchronous dynamic random access memory capable of accessing data in a memory cell array therein in synchronism with a system clock from an external system such as a central processing unit (CPU). The synchronous DRAM receives an external clock and includes a plurality of memory banks each including a plurality of memory cells and operable in either an active cycle or a precharge cycle, a circuit for receiving a row address strobe signal and latching a logic level of the row address strobe signal in response to the clock, an address input circuit for receiving an externally generated address selecting one of the memory banks, and a circuit for receiving the latched logic level and the address from the address input circuit and for outputting an activation signal to the memory bank selected by the address and an inactivation signals to unselected memory banks when the latched logic level is a first logic level, so that the selected memory bank responsive to the activation signal operates in the active cycle while the unselected memory banks responsive to the inactivation signals operate in the precharge cycle.
摘要:
A synchronous dynamic random access memory capable of accessing data in a memory cell array therein in synchronism with a system clock from an external system such as a central processing unit (CPU). The synchronous DRAM receives an external clock and includes a plurality of memory banks each including a plurality of memory cells and operable in either an active cycle or a precharge cycle, a circuit for receiving a row address strobe signal and latching a logic level of the row address strobe signal in response to the clock, an address input circuit for receiving an externally generated address selecting one of the memory banks, and a circuit for receiving the latched logic level and the address from the address input circuit and for outputting an activation signal to the memory bank selected by the address and an inactivation signals to unselected memory banks when the latched logic level is a first logic level, so that the selected memory bank responsive to the activation signal operates in the active cycle while the unselected memory banks responsive to the inactivation signals operate in the precharge cycle.
摘要:
A synchronous dynamic random access memory capable of accessing data in a memory cell array therein in synchronism with a system clock from an external system such as a central processing unit (CPU). The synchronous DRAM receives an external clock and includes a plurality of memory banks each including a plurality of memory cells and operable in either an active cycle or a precharge cycle, a circuit for receiving a row address strobe signal and latching a logic level of the row address strobe signal in response to the clock, an address input circuit for receiving an externally generated address selecting one of the memory banks, and a circuit for receiving the latched logic level and the address from the address input circuit and for outputting an activation signal to the memory bank selected by the address and an inactivation signals to unselected memory banks when the latched logic level is a first logic level, so that the selected memory bank responsive to the activation signal operates in the active cycle while the unselected memory banks responsive to the inactivation signals operate in the precharge cycle.
摘要:
A synchronous dynamic random access memory capable of accessing data in a memory cell array therein in synchronism with a system clock from an external system such as a central processing unit (CPU). The synchronous DRAM receives an external clock and includes a plurality of memory banks each including a plurality of memory cells and operable in either an active cycle or a precharge cycle, a circuit for receiving a row address strobe signal and latching a logic level of the row address strobe signal in response to the clock, an address input circuit for receiving an externally generated address selecting one of the memory banks, and a circuit for receiving the latched logic level and the address from the address input circuit and for outputting an activation signal to the memory bank selected by the address and an inactivation signals to unselected memory banks when the latched logic level is a first logic level, so that the selected memory bank responsive to the activation signal operates in the active cycle while the unselected memory banks responsive to the inactivation signals operate in the precharge cycle.
摘要:
A synchronous dynamic random access memory capable of accessing data in a memory cell array therein in synchronism with a system clock from an external system such as a central processing unit (CPU). The synchronous DRAM receives an external clock and includes a plurality of memory banks each including a plurality of memory cells and operable in either an active cycle or a precharge cycle, a circuit for receiving a row address strobe signal and latching a logic level of the row address strobe signal in response to the clock, an address input circuit for receiving an externally generated address selecting one of the memory banks, and a circuit for receiving the latched logic level and the address from the address input circuit and for outputting an activation signal to the memory bank selected by the address and an inactivation signals to unselected memory banks when the latched logic level is a first logic level, so that the selected memory bank responsive to the activation signal operates in the active cycle while the unselected memory banks responsive to the inactivation signals operate in the precharge cycle.
摘要:
A semiconductor memory device using a clock of a constant period supplied from the exterior of a memory chip and a sense amplifier for reading out data from a memory cell designated by an address includes at least two different delay circuits for setting at least two delay time periods from the clock, a selecting circuit for receiving signals generated from the delay circuits and selecting one of said signals by a given control signal, and a data output buffer for receiving the data generated from the sense amplifier by a signal generated from the selecting circuit.
摘要:
A semiconductor memory device stably operates over a wide range of the power supply voltage by including a power supply voltage level detector for generating detecting signals according to predetermined levels of the power supply voltage and an oscillator for generating a frequency-controlled oscillation pulse whose frequency is changeable according to the detecting signals. Thus, a boosting ratio of a boosting circuit, the refresh period of a refresh circuit and the substrate voltage of a substrate voltage generator can be adaptively changeable according to the variation of the power supply voltage.
摘要:
A semiconductor memory device stably operates over a wide range of the power supply voltage by including a power supply voltage level detector for generating detecting signals according to predetermined levels of the power supply voltage and an oscillator for generating a frequency-controlled oscillation pulse whose frequency is changeable according to the detecting signals. Thus, a boosting ratio of a boosting circuit, the refresh period of a refresh circuit and the substrate voltage of a substrate voltage generator can be adaptively changeable according to the variation of the power supply voltage.
摘要:
A semiconductor memory device stably operates over a wide range of the power supply voltage by including a power supply voltage level detector for generating detecting signals according to predetermined levels of the power supply voltage and an oscillator for generating a frequency-controlled oscillation pulse whose frequency is changeable according to the detecting signals. Thus, a boosting ratio of a boosting circuit, the refresh period of a refresh circuit and the substrate voltage of a substrate voltage generator can be adaptively changeable according to the variation of the power supply voltage.