摘要:
A first test circuit (21) is connected to one end of a first wiring line (40), and a second test circuit (22) is connected to one end of a second wiring line (41). The second wiring line (41) serves as a data bus. N-channel MOS transistors (50, 51), connected in series, are provided between the first and second wiring lines (40, 41) and located below a third wiring line (42). The transistors (50, 51) are set in an conductive state by a gate control signal (TEST) from a test control circuit (53) in a test mode, and are set in an OFF state in a normal operation mode. In the normal operation mode, the capacitance between the first and second wiring lines (40, 41) is small and does not adversely affect the operation speed of an integrated circuit.
摘要:
A manufacturing method of a semiconductor memory device includes the steps of selectively forming a field oxide film (22) and a gate oxide film (21) on a semiconductor substrate (20), depositing a first conductive layer (23) on an entire surface of the resultant structure, selectively etching the first conductive layer (23) located in a region other than an element region, oxidation of the entire surface of the resultant structure, depositing a second conductive layer (27) on an entire surface of the resultant structure, and etching the first conductive layer (23), the oxide film (26), and the second conductive layer (27) using the same mask to form a plurality of floating gates by the first conductive layer (23) and to form a plurality of control gates by the second conductive layer (27), wherein the step of selectively etching the first conductive layer (23) includes the first etching step of forming cell slits (24) for separating the plurality of floating gates from each other and the second etching step of forming removed regions (25) each of which includes only one end of each of the plurality of control gates.
摘要:
A manufacturing method of a semiconductor memory device includes the steps of selectively forming a field oxide film (22) and a gate oxide film (21) on a semiconductor substrate (20), depositing a first conductive layer (23) on an entire surface of the resultant structure, selectively etching the first conductive layer (23) located in a region other than an element region, oxidation of the entire surface of the resultant structure, depositing a second conductive layer (27) on an entire surface of the resultant structure, and etching the first conductive layer (23), the oxide film (26), and the second conductive layer (27) using the same mask to form a plurality of floating gates by the first conductive layer (23) and to form a plurality of control gates by the second conductive layer (27), wherein the step of selectively etching the first conductive layer (23) includes the first etching step of forming cell slits (24) for separating the plurality of floating gates from each other and the second etching step of forming removed regions (25) each of which includes only one end of each of the plurality of control gates.
摘要:
A potential detecting circuit comprises a first MOS transistor (N6, P6) of a first conductivity type whose drain receives an input potential whose absolute which is equal to or lower, in absolute value, than a second potential whose absolute value is higher than that of a first potential, a second MOS transistor of a second conductivity type whose source is connected to the source of the first transistor and gate receives the first potential, a third MOS transistor (N11, P11) of the first conductivity type whose source is connected to the second MOS transistor (P5, N5), source receives a reference potential whose absolute value is lower than that of the first potential, and gate receives the first potential, a detecting potential control block for applying to the first MOS transistor a potential varying in accordance with the input potential, and a potential detect output terminal for providing a detected potential, the potential detect output terminal being a junction between the drains of the second and third MOS transistors.
摘要:
A first test circuit (21) is connected to one end of a first wiring line (40), and a second test circuit (22) is connected to one end of a second wiring line (41). The second wiring line (41) serves as a data bus. N-channel MOS transistors (50, 51), connected in series, are provided between the first and second wiring lines (40, 41) and located below a third wiring line (42). The transistors (50, 51) are set in an conductive state by a gate control signal (TEST) from a test control circuit (53) in a test mode, and are set in an OFF state in a normal operation mode. In the normal operation mode, the capacitance between the first and second wiring lines (40, 41) is small and does not adversely affect the operation speed of an integrated circuit.
摘要:
A programmable logic unit circuit comprising a data memory circuit (10), a combinational logic circuit (13) supplied with at least two input signals, two input select circuits (11,12) for, based on the stored data in the data memory circuit (10), selecting the two input signals supplied to the combinational logic circuit (13) from more than two input signals, a clock-synchronized circuit (14) for supplying the output signal from the combinational logic circuit (13) in synchronization with a clock signal, and a 3-state-output type output select circuit (16) for selecting either the output signal of the combinational logic circuit (13) or the output signal of the clock-synchronized circuit (14), depending on the stored data in the data memory circuit (10).
摘要:
A programmable logic circuit for deriving a logic output of first and second signals includes a 2-input logic gate (2) for deriving a logic output of two signals. The 2-input logic gate (2) is constituted by connecting two 3-state circuits (1₁, 1₂) in a wired OR configuration. One (1₁) of the 3-state circuits includes a data input terminal, output control input terminal, and data output terminal, the output control input terminal receives an inverted signal ( B ) of the second signal, and the data output terminal is set to one of three states of "1", "0", and the high impedance. Likewise, the other 3-state circuit (1₂) includes a data input terminal, output control input terminal, and data output terminal, the output control input terminal receives the second signal (B), and the data output terminal is set to one of three states of "1", "0", and the high impedance. Each of the data input terminals of the 3-state circuits (1₁, 1₂) is supplied with a desired one of the first signal (A), an inverted signal ( A ) of the first signal, a "0" level signal, and a "1" level signal in a programmable fashion. Various logic gates can be realized by programming the supplying states of the four signals.
摘要:
An EPROM integrated circuit (20) includes a plurality of banks. When a data write operation is to be performed for this EEPROM integrated circuit (20), a bank which is used once is not used again, but the operation is constantly performed for new banks. In order to select a bank, a write number storage area (21) is provided in the EPROM integrated circuit (20), and the contents of the write number storage area (21) are updated by a write number updating circuit (29) each time the write operation is performed for a new bank.
摘要:
A potential detecting circuit comprises a first MOS transistor (N6, P6) of a first conductivity type whose drain receives an input potential whose absolute which is equal to or lower, in absolute value, than a second potential whose absolute value is higher than that of a first potential, a second MOS transistor of a second conductivity type whose source is connected to the source of the first transistor and gate receives the first potential, a third MOS transistor (N11, P11) of the first conductivity type whose source is connected to the second MOS transistor (P5, N5), source receives a reference potential whose absolute value is lower than that of the first potential, and gate receives the first potential, a detecting potential control block for applying to the first MOS transistor a potential varying in accordance with the input potential, and a potential detect output terminal for providing a detected potential, the potential detect output terminal being a junction between the drains of the second and third MOS transistors.