Abstract: A memory controller converts controller output signals output from a controller into memory input signals according to the operation specifications of memory chips to operate, and outputs the resultant to the memory chips through a common bus. The memory controller also receives memory output signals output from the memory chips through the common bus, and converts the received signals into controller input signals receivable to the controller. This allows the single memory controller to access the plurality of types of memory chips. As a result, the memory controller can be reduced in chip size, lowering the cost of the memory system.

Abstract: A semiconductor device, includes: a first field effect transistor having one terminal to which a first electrical potential is given; a second field effect transistor having one terminal to which a second electrical potential smaller than the first electrical potential is given; a controller that controls each electrical potential of each control terminal of the first field effect transistor and the second field effect transistor; a capacitor element having one end connected to the control terminal of the first field effect transistor, the capacitor element being charged by the control of the controller; and a load element connected between another terminal of the first field effect transistor and another terminal of the second field effect transistor.

Abstract: A transistor circuit includes a first high electron mobility transistor and a second high electron mobility transistor having a negative threshold voltage, wherein a source of the second high electron mobility transistor is coupled to a gate of the first high electron mobility transistor, and a gate of the second high electron mobility transistor is coupled to a source of the first high electron mobility transistor.

Abstract: A semiconductor device includes a first transistor including a GaN-based semiconductor stacked structure formed over a substrate, a first gate electrode having a plurality of first fingers over the semiconductor stacked structure, a plurality of first drain electrodes provided along the first fingers, and a plurality of first source electrodes provided along the first fingers; a second transistor including the semiconductor stacked structure, a second gate electrode having a plurality of second fingers over the semiconductor stacked structure, the second drain electrodes provided along the second fingers, and a plurality of second source electrodes provided along the second fingers; a drain pad provided over or under the first drain electrodes, and coupled to the first drain electrodes; a source pad provided over or under the second source electrodes, and coupled to the second source electrodes; and a common pad coupled to the first source electrodes and the second drain electrodes.

Abstract: A transistor circuit includes a first high electron mobility transistor and a second high electron mobility transistor having a negative threshold voltage, wherein a source of the second high electron mobility transistor is coupled to a gate of the first high electron mobility transistor, and a gate of the second high electron mobility transistor is coupled to a source of the first high electron mobility transistor.

Abstract: A control circuit, which controls a transistor including a gate and a field plate, includes: a detecting circuit which detects a driving timing to drive the transistor; a timing controlling circuit which controls a first driving timing to drive the gate and a second driving timing to drive the field plate, in response to the driving timing; and a driving circuit which drives the gate in response to the first driving timing, and drives the field plate in response to the second driving timing.

Abstract: A drive circuit of a power unit, which includes a high-side transistor and a low-side transistor connected in series between a high potential power-supply line and a low potential power-supply line, and an inductor provided between a connection node of both of the transistors and an output terminal, and which drives both of the transistors, the drive circuit has: a first gate driver which drives a gate of the high-side transistor; and a second gate driver which drives a gate of the low-side transistor. In a transitional period of changing from a first state where the high-side transistor is ON and the low-side transistor is OFF to a second state where the high-side transistor is OFF and the low-side transistor is ON, the first gate driver drives the gate of the high-side transistor to a first voltage which is lower than a potential of the low potential power-supply line.

Abstract: A memory controller converts controller output signals output from a controller into memory input signals according to the operation specifications of memory chips to operate, and outputs the resultant to the memory chips through a common bus. The memory controller also receives memory output signals output from the memory chips through the common bus, and converts the received signals into controller input signals receivable to the controller. This allows the single memory controller to access the plurality of types of memory chips. As a result, the memory controller can be reduced in chip size, lowering the cost of the memory system.

Abstract: A switching circuit device provided between a first node and a second node within a power supply circuit, an inductor being coupled to the first or second node, the switching circuit device has: a first transistor that is provided between the first node and the second node and has a first gate width; a second transistor that is provided in parallel with the first transistor between the first node and the second node and has a second gate width larger than the first gate width; and a driving signal generation circuit, which, in response to a control signal generated according to an output voltage of the power supply circuit, outputs a first driving signal which drives the first transistor on and off, and a second driving signal which drives the second transistor on and off, with different timings between the first driving signal output and the second driving signal output.

Abstract: A switching circuit device has a first transistor which has a drain coupled to a high-potential terminal, a source coupled to a low-potential power supply, and, a driving circuit, which outputs, to a gate of the first transistor in response to an input control signal, a pulse having a potential higher than a threshold voltage of the first transistor and a potential of the low-potential power supply, wherein the driving circuit has a first inverter including a second transistor provided between the gate and the source of the first transistor, wherein when the first transistor changes from on to off due to the pulse, the second transistor conducts and short-circuits the gate and the source of the first transistor.

Abstract: A transistor circuit includes a first high electron mobility transistor and a second high electron mobility transistor having a negative threshold voltage, wherein a source of the second high electron mobility transistor is coupled to a gate of the first high electron mobility transistor, and a gate of the second high electron mobility transistor is coupled to a source of the first high electron mobility transistor.

Abstract: A control circuit, which controls a transistor including a gate and a field plate, includes: a detecting circuit which detects a driving timing to drive the transistor; a timing controlling circuit which controls a first driving timing to drive the gate and a second driving timing to drive the field plate, in response to the driving timing; and a driving circuit which drives the gate in response to the first driving timing, and drives the field plate in response to the second driving timing.

Abstract: A semiconductor device includes a first transistor including a GaN-based semiconductor stacked structure formed over a substrate, a first gate electrode having a plurality of first fingers over the semiconductor stacked structure, a plurality of first drain electrodes provided along the first fingers, and a plurality of first source electrodes provided along the first fingers; a second transistor including the semiconductor stacked structure, a second gate electrode having a plurality of second fingers over the semiconductor stacked structure, the second drain electrodes provided along the second fingers, and a plurality of second source electrodes provided along the second fingers; a drain pad provided over or under the first drain electrodes, and coupled to the first drain electrodes; a source pad provided over or under the second source electrodes, and coupled to the second source electrodes; and a common pad coupled to the first source electrodes and the second drain electrodes.

Abstract: A semiconductor memory has a field programmable unit in which logic to inter-convert external signals to be input/output to/from a memory system and internal signals to be input/output to/from a memory cell array is programmed. A program for constructing the logic of the field programmable unit is stored in a nonvolatile program memory unit. Through the field programmable unit, a controller can access the memory cell array, even when the interface of the controller accessing the semiconductor memory is different from an interface for accessing the memory cell array. Therefore, one kind of semiconductor memory can be used as plural kinds of semiconductor memories. This eliminates the need to develop plural kinds of semiconductor memories, reducing a development cost.

Abstract: A conversion control unit sets a converting function of a write data conversion unit or a read data conversion unit enabled or disabled for each controller. Accordingly, for a controller which needs original external data, the external data can be inputted and outputted, whereas for a controller which needs converted internal data, the internal data can be inputted and outputted. A data converting function of a conventional controller can be realized in a semiconductor memory, which can reduce the load on the controller. As a result, the performance of a system can be improved. A disabled controller which has no access right cannot read correct data (original data before conversion). Hence, the security of data written into the semiconductor memory can be protected.

Abstract: A volatile memory has a volatile additional area for storing an error correction code for a nonvolatile memory. Data stored in the nonvolatile memory are transferred to the volatile memory together with the error correction code without making an error correction. Thus, data transfer time from the nonvolatile memory to the volatile memory can be shortened. As a result, it is possible to shorten the time from beginning of the data transfer from the nonvolatile memory to the volatile memory to a point at which data becomes accessible.

Abstract: A memory controller converts controller output signals output from a controller into memory input signals according to the operation specifications of memory chips to operate, and outputs the resultant to the memory chips through a common bus. The memory controller also receives memory output signals output from the memory chips through the common bus, and converts the received signals into controller input signals receivable to the controller. This allows the single memory controller to access the plurality of types of memory chips. As a result, the memory controller can be reduced in chip size, lowering the cost of the memory system.

Abstract: A memory controller converts controller output signals output from a controller into memory input signals according to the operation specifications of memory chips to operate, and outputs the resultant to the memory chips through a common bus. The memory controller also receives memory output signals output from the memory chips through the common bus, and converts the received signals into controller input signals receivable to the controller. This allows the single memory controller to access the plurality of types of memory chips. As a result, the memory controller can be reduced in chip size, lowering the cost of the memory system.

Abstract: A controller converts a parallel command signal and address signal, or a parallel write data signal into a first serial signal, and outputs the converted signal as a first optical signal with a single wavelength to a memory device via an optical transmission line. The memory device converts the first optical signal into the original parallel command signal, address signal, and write data signal, and outputs the converted parallel signals to a memory unit. The memory device converts a parallel read data signal from the memory unit into a second serial signal, and outputs the converted signal to the controller via the optical transmission line as a second optical signal with a single wavelength. It is unnecessary to transmit the optical signal using an optical multiplexer, an optical demultiplexer, etc., thereby improving transmission rate of signals transmitted between the controller and the memory device at minimum cost.

Abstract: A memory controller multiplexes access signals each consisting of a plurality of bits as optical signals and outputs the multiplexed optical signals. At this time, the optical signals whose wavelengths differ depending on memory devices are generated. A memory interface unit demultiplexes the multiplexed optical signals into the original optical signals and converts the demultiplexed optical signals into electrical signals. The memory interface unit determines to which of the memory devices the electrical signals resulting from the conversion should be outputted, according to the wavelengths of the demultiplexed optical signals. This frees the memory controller from a need for transmitting to the memory interface unit a signal for identifying the memory device. The memory interface unit need not include a decoding circuit for identifying the memory device.