摘要:
A semiconductor memory device is disclosed. A block unit is divided into memory mats based on an internal address. In the case where the internal address is “1”, data are read in ascending order in accordance with a start address from the memory mat, while the internal address is incremented by an address conversion circuit thereby to select a 4-word block including the words next selected from the memory mat. At the same time, the internal address is incremented based on the start address, so that the period for reading each word included in the lowest order of 4-word block can be secured. In the process, the address next to be input can be decoded.
摘要:
In the output circuit, at a subsequent stage of a gate circuit operating with a power supply voltage related to a first power supply voltage, a latch circuit formed of an inverter circuit and a MOS transistor is arranged, and is supplied with a second power supply voltage as an operating power supply voltage. An output buffer circuit is driven in accordance with an output signal of the latch circuit. When the first power supply voltage is powered down, the latch circuit receiving and operating with the second power supply voltage holds a signal voltage to be attained in a standby state and thus the output buffer circuit is reliably held in an output high impedance state. In a semiconductor device of a double power supply configuration, even when one power supply is powered down, the output buffer circuit can reliably be set to an output high impedance state.
摘要:
A clock buffer of a DRAM includes: a first NAND gate which is driven by a first internal power supply voltage (2.5 V) and which determines the level of an input clock signal if the DRAM is used for a TTL-system interface (MLV=2.5 V); and a second NAND gate which is driven by a second internal power supply voltage (1.8 V) and which determines the level of the input clock signal if the DRAM is used for a 1.8 V-system interface (MLV=0 V). Accordingly, in each of the first and second NAND gates, sizes of four MOS transistors can be set at optimum values, respectively.
摘要:
A level conversion circuit is provided, at an output, with an initialization circuit for setting the output signal of the level conversion circuit for generating a power cut enable signal controlling a deep power down mode to a predetermined inactive state upon power up. The initialization circuit is constituted by, for example, a capacitive element connected to the output node of the level conversion circuit to pull up the voltage of the output node upon power up, and a latch circuit latching the voltage level of the output node. When power is on, the power cut enable signal is forcibly inactivated by the initialization circuit to generate a periphery power supply voltage. The internal node of the level conversion circuit is initialized according to the output signal of a control circuit receiving the periphery power supply voltage as an operating power supply voltage. In semiconductor memory device having a deep power down mode, an internal voltage is generated reliably and properly upon power up of an internal voltage.
摘要:
A semiconductor device comprises an MOS transistor, as a capacitive element, formed at the surface of a semiconductor substrate. A first power supply interconnection, above the substrate, applies a first power supply potential to the source and drain of the transistor. A second power supply interconnection, above the first interconnection, applies a second potential to the gate of the transistor. A third power supply interconnection is formed above, in parallel with and connected to the second power supply interconnection. An externally sourced potential is down-converted to be applied appropriately to the first, second and third power supply interconnections. This configuration achieves a semiconductor device that is less susceptible to power supply noise.
摘要:
A semiconductor memory device includes a memory cell array, peripheral circuits including a column decoder for connecting a word line, and a VDC circuit for peripherals, for generating an internal power supply voltage based on an external power supply voltage. VDC circuit for peripherals supplies the internal power supply voltage to peripheral circuits including the column decoder, other than the sense amplifier, output buffer and internal initial stage. The supplying capability of the VDC circuit for peripherals is increased in response to a VDCE signal which is output from a clock generation circuit when column decoder is activated. Therefore, even when power consumption in the peripheral circuit is increased as the column decoder is activated, sufficient power can be supplied to the peripheral circuit.
摘要:
A semiconductor device includes a PMOS transistor and an NMOS transistor. In a standby state, a potential of Vcc level is applied to the substrate of the PMOS transistor and a potential of Vss level is applied to the substrate of the NMOS transistor. Therefore, the voltage between the source and substrate of the P and NMOS transistors becomes 0 V. In an active state, potentials that render the voltage between the source and substrate lower than the built-in potential are applied to respective substrates of the P and NMOS transistors. Therefore, the threshold voltage of the transistor is lowered in an active state than in a standby state, and almost no leakage current flows between the source and substrate.
摘要:
A semiconductor memory device operates switched between a first readout mode in which data readout according to a specified activation of a column address strobe signal /CAS that shows a transition in synchronization with an external clock signal is output during a period including the specified activation of signal /CAS, and a second readout mode in which the readout data is output during a subsequent predetermined period of signal /CAS. A control circuit for controlling the data output timing from an output buffer activates the output buffer at an elapse of a predetermined time following the specified activation of signal /CAS in the first readout mode. In the second readout mode, the control circuit activates the output buffer according to activation of signal /CAS at a predetermined period.
摘要:
A lead frame of a DRAM chip includes a base end portion to which an external power supply potential ext.cndot.VCC is applied, and two branch portions branching away from the base end portion. A tip portion of one of these two branch portions is connected to an output buffer, and a tip portion of the other is connected to another circuit. Power supply noise generated at the output buffer passes through one of the branch portions to the outside, and will never reach another circuit through the other branch portion. Accordingly, a DRAM which is less susceptible to power supply noise can be provided.
摘要:
A memory apparatus includes a control circuit, a plurality of memory arrays, each of which contains a plurality of memory cells, and a current detecting circuit. The current detecting circuit measures a quantity of a current of a first memory array. A redundancy information is changed when the quantity of the current of the first memory array is over a first current quantity detected by the current detecting circuit. The control circuit controls an access to the memory arrays, and changes the access to the first memory array to a second memory array in accordance with the redundancy information.