摘要:
A programming circuit for a programmable read only memory device receiving a data signal to be programmed including a power supply terminal for receiving a first voltage in a read mode and a second voltage as a programming voltage which is a higher voltage than the first voltage in a program mode; an inverter circuit for converting an amplitude of the data signal in the program mode, the inverter including a load element and a first transistor having a drain connected to the load element and a gate receiving the data signal; and a switching circuit connected between the power source terminal and the load element for supplying the second voltage in the program mode and inhibiting a supply of the first voltage in the read mode.
摘要:
A decoder circuit fabricated in an IC memory chip and provided to respective word-lines and respective bit-lines of an IC memory matrix fabricated in the IC memory chip, is provided for selecting an EPROM cell which is placed on an intersection point of the word-line and the bit-line, to program a datum into the EPROM cell by using a high power supply voltage when the decoder circuit operates under a programming mode and to read out a datum stored in the EPROM cell by using a low power supply voltage when the decoder circuit operates under a reading mode, receiving an address signal from the exterior of the decoder circuit. The decoder circuit comprises a NAND gate having its load and a CMOS invertor. In making the load of the NAND gate function as a constant current load, only a variable power supply voltage, which becomes a high and a low voltage according to the programming and the reading mode respectively, can be applied to the decoder circuit without using other elements such as a transfer gate and a compensator as required in the prior art.
摘要:
A memory system having an erasable programmable read only memory (EPROM) for storing principal data, a read only memory (ROM) for storing key data, and a processing unit for writing or reading the principal data into or from the EPROM under control of the key data. The EPROM has an address converter having a volatile memory for temporarily storing the key data. External address data for wiring the principal data into the EPROM are converted to internal address data by the address converter using the key data stored in the volatile memory; the principal data stored in the EPROM are read out by converting external address data into internal address data, again using the key data stored in the volatile memory. The key data stored in the ROM are read out and applied to the volatile memory during the power turn-on of the memory system, the key data controlling the processing by the processing unit.
摘要:
An output circuit of a semiconductor device for suppressing erroneous operation due to potential variations of the power supply line or the ground line. The output circuit comprises an output stage inverter connected between the power supply line and the ground line and a clamping circuit for clamping the voltages applied to the output stage inverter. A large instantaneous current which flows through the output stage inverter during a transition of state is greatly suppressed so that erroneous operation is prevented.
摘要:
A semiconductor EPROM device which comprises a plurality of floating gate type memory cell transistors and in which the threshold potential of the memory cell transistors is measured by changing the potential of a second power supply terminal to which is originally connected a high potential used for programming the EPROM device.
摘要:
An image forming apparatus includes a sheet bundle housing unit that houses recording sheets piled as a sheet bundle; a swing member having a sheet contact portion on one end side, and swinging between a projection position at which the sheet contact portion projects above a sheet placement surface of the housing unit and a non-projection position at which the sheet contact portion does not project above the sheet placement surface, the swing member moving from the projection position to the non-projection position by the sheet bundle; a sheet detection unit that detects the sheet bundle in the housing unit using the swing member; and an interlocking mechanism that moves the swing member to the non-projection position, regardless of presence or absence of the sheet bundle in the housing unit, by interlocking with the housing unit being pulled out from an apparatus body.
摘要:
An X-ray detector for use in a medical X-ray imaging apparatus comprising a rotary means rotatable relative to an object to be examined, an X-ray generator provided at one side of the rotary means, and an X-ray detecting portion provided at the other side of the rotary means so as to face the X-ray generator. The X-ray detector is provided in the X-ray detecting portion or is detachably mounted in the X-ray detecting portion, the X-ray detector is provided with an imaging portion comprised of a plane electric imaging means extending in a two-dimensional direction used for X-ray CT and has an imaging portion positioning means for moving up and down the imaging portion in the X-ray detector.
摘要:
A semiconductor device has a function of reading device information specific to the device as and when required. The semiconductor device has storage units for storing plural pieces of device information and a selector for selecting a predetermined one of the information pieces stored in the storage units when a device information read mode is set, so that the read information may match device data such as a manufacturer name and part name printed on the semiconductor device.
摘要:
A nonvolatile semiconductor memory employs sense amplifiers, circuits for providing stabilized source voltages, and circuits for realizing high-speed and reliable read and write operations. The semiconductor memory has a matrix of nonvolatile erasable memory cell transistors. The semiconductor memory employs an arrangement for effectively using a plurality of source voltages and applying a verify voltage to sense amplifiers and word lines, a write verify arrangement for detecting an output of the sense amplifiers, an arrangement for comparing an output of the sense amplifiers with a reference value to determine whether or not a written state of the memory cell transistors is acceptable, an arrangement for adjusting an output of the sense amplifiers with use of inverters and transistors in response to a current flowing to the memory cell transistors, to improve a drive speed of the sense amplifiers, an internal source voltage generating arrangement using an n-channel depletion transistor connected to an external source voltage (V.sub.CC), the gate of the transistor being connected to a low source voltage (V.sub.ss) to provide an internal source voltage (V.sub.ci), a combination of an arrangement for dropping the external source voltage (V.sub.cc) for read to a predetermined value to drive a read circuit in the memory and an arrangement for dropping an external voltage (V.sub.pp) for write, to generate a word line potential for a verify-after-write operation, an arrangement for setting a reference voltage (V.sub.ref) as a lower threshold (V.sub.th) allowed for cell transistors (11.sub.00 to 11.sub.22), and comparing the voltage of a data bus (13) with the reference voltage (V.sub.ref), to simultaneously carry out an erase-verify operation on all memory cell transistors, and a pre-read arrangement for accessing the next address during a read time of the sense amplifiers, to improve a read speed.
摘要:
A nonvolatile semiconductor memory employs sense amplifiers, circuits for providing stabilized source voltages, and circuits for realizing high-speed and reliable read and write operations. The semiconductor memory has a matrix of nonvolatile erasable memory cell transistors. The semiconductor memory employs an arrangement for effectively using a plurality of source voltages and applying a verify voltage to sense amplifiers and word lines, a write verify arrangement for detecting an output of the sense amplifiers, an arrangement for comparing an output of the sense amplifiers with a reference value to determine whether or not a written state of the memory cell transistors is acceptable, an arrangement for adjusting an output of the sense amplifiers with use of inverters and transistors in response to a current flowing to the memory cell transistors, to improve a drive speed of the sense amplifiers, an internal source voltage generating arrangement using an n-channel depletion transistor connected to an external source voltage (Vcc), the gate of the transistor being connected to a low source voltage (Vss) to provide an internal source voltage (Vci), a combination of an arrangement for dropping the external source voltage (Vcc) for read to a predetermined value to drive a read circuit in the memory and an arrangement for dropping an external voltage (Vpp) for write, to generate a word line potential for a verify-after-write operation, an arrangement for setting a reference voltage (Vref) as a lower threshold (Vth) allowed for cell transistors (11.sub.00 to 11.sub.22), and comparing the voltage of a data bus (13) with the reference voltage (Vref), to simultaneously carry out an erase-verify operation on all memory cell transistors, and a pre-read arrangement for accessing the next address during a read time of the sense amplifiers, to improve a read speed.