Abstract: An asynchronous interface according to the disclosure includes: a transmission circuit that transmits, with data of W bits as one word, the data on the one-word basis, and transmits an REQ signal whose value differs by one bit per transmission of the data of one word; a reception circuit including a reception buffer having a reception buffer word count of n (n is an integer of 4 or more), in which the reception circuit receives the data on the one-word basis, and transmits an ACK signal whose value differs by one bit per reception of the data of one word; a data signal line that has a bit width of W, and transfers the data from the transmission circuit to the reception circuit; an REQ signal line that has a bit width of log2 (n) or more, and transfers the REQ signal from the transmission circuit to the reception circuit; and an ACK signal line that has a bit width of log2(n) or more, and transfers the ACK signal from the reception circuit to the transmission circuit.

Abstract: A control circuit of power gating of the present disclosure includes a control section that controls whether to perform power gating depending on a level of a clock signal for a logic circuit supplied with a power supply voltage through a power switch transistor, on the basis of a clock frequency of the clock signal.

Abstract: A control circuit of power gating of the present disclosure includes a control section that controls whether to perform power gating depending on a level of a clock signal for a logic circuit supplied with a power supply voltage through a power switch transistor, on the basis of a clock frequency of the clock signal.

Abstract: An asynchronous interface according to the disclosure includes: a transmission circuit that transmits, with data of W bits as one word, the data on the one-word basis, and transmits an REQ signal whose value differs by one bit per transmission of the data of one word; a reception circuit including a reception buffer having a reception buffer word count of n (n is an integer of 4 or more), in which the reception circuit receives the data on the one-word basis, and transmits an ACK signal whose value differs by one bit per reception of the data of one word; a data signal line that has a bit width of W, and transfers the data from the transmission circuit to the reception circuit; an REQ signal line that has a bit width of log2(n) or more, and transfers the REQ signal from the transmission circuit to the reception circuit; and an ACK signal line that has a bit width of log2(n) or more, and transfers the ACK signal from the reception circuit to the transmission circuit.

Abstract: Disclosed herein is a clock supplying apparatus for supplying a clock to a digital circuit, including: a differential clock driver; a first clock line along which a first clock of a positive phase from the clock driver propagates; a second clock line along which a second clock of a reverse phase from the clock driver propagates; and a parallel resonance circuit of an inductor and a capacitor. The inductor of the parallel resonance circuit is connected at a first end to the first clock line and at a second end to the second clock line. The capacitor of the parallel resonance circuit is connected at a first electrode to the first clock line and at a second electrode to the second clock line.

Abstract: A digital DLL circuit includes: a first register configured to hold a first delay specifying value to specify a delay of a rising edge side of a signal; a second register configured to hold a second delay specifying value to specify a delay of a falling edge side of a signal; and a digitally-controlled variable delay circuit configured to be allowed to individually control delays of a rise side and a fall side of a signal. The digital DLL circuit further includes a control circuit configured to implement control so that a rise-side delay and a fall-side delay by the variable delay circuit are kept at the first delay specifying value of the first register and the second delay specifying value of the second register, respectively.

Abstract: A digital DLL circuit includes: a register configured to hold a delay target value; an oscillator; a first counter configured to count an external reference clock or an oscillation output from the oscillator; a second counter configured to count the oscillation output from the oscillator or the external reference clock in every measurement cycle determined by the first counter; and a digitally-controlled variable delay circuit. The DLL circuit further includes a control circuit configured to control the reset and activation of the first counter and the second counter, and control the stop of the first and second counters according to need, based on a count value of the first counter, the control circuit subjecting a count value of the second counter and the delay target value of the register to a digital arithmetic operation, and supplying the variable delay circuit with a result of the arithmetic operation as a delay control value.

Abstract: A digital DLL circuit includes: a first register configured to hold a delay specifying value to specify a delay; a second register configured to specify a correction value for a gate delay inside an LSI; a digitally-controlled variable delay circuit; and a control circuit configured to produce a delay control value to implement control so that a delay by the variable delay circuit is kept at the delay specifying value of the first register. The digital DLL circuit further includes an adder circuit configured to add a gate delay correction value held by the second register to the delay control value output from the control circuit, and output a resultant value to a control input of the variable delay circuit.

Abstract: A logic processing circuit including a plurality of flip-flop including a front stage flip-flop and a rear stage flip-flop, a logic gate circuit network adapted to process data stored in the front stage flip-flop, a result of the process being stored in the rear stage flip-flop, and switching means for switching between a power-on period and a power-off period, the power-on period being a period in which power is being provided to the logic gate circuit network, the power-on period corresponding to either a low-level state period of a clock signal or a high-level state period thereof, the power-off period being a period in which the power is being turned off, the power-off period corresponding to the state period other than the state period corresponding to the power-on period.

Abstract: Disclosed herein is a clock supplying apparatus for supplying a clock to a digital circuit, including: a differential clock driver; a first clock line along which a first clock of a positive phase from the clock driver propagates; a second clock line along which a second clock of a reverse phase from the clock driver propagates; and a parallel resonance circuit of an inductor and a capacitor. The inductor of the parallel resonance circuit is connected at a first end to the first clock line and at a second end to the second clock line. The capacitor of the parallel resonance circuit is connected at a first electrode to the first clock line and at a second electrode to the second clock line.

Abstract: A digital DLL circuit includes: a register configured to hold a delay target value; an oscillator; a first counter configured to count an external reference clock or an oscillation output from the oscillator; a second counter configured to count the oscillation output from the oscillator or the external reference clock in every measurement cycle determined by the first counter; and a digitally-controlled variable delay circuit. The DLL circuit further includes a control circuit configured to control reset and activation of the first counter and the second counter, and control stop of the first and second counters according to need, based on a count value of the first counter, the control circuit subjecting a count value of the second counter and the delay target value of the register to digital arithmetic operation, and supplying the variable delay circuit with a result of the arithmetic operation as a delay control value.

Abstract: A digital DLL circuit includes: a first register configured to hold a first delay specifying value to specify a delay of a rising edge side of a signal; a second register configured to hold a second delay specifying value to specify a delay of a falling edge side of a signal; and a digitally-controlled variable delay circuit configured to be allowed to individually control delays of a rise side and a fall side of a signal. The digital DLL circuit further includes a control circuit configured to implement control so that a rise-side delay and a fall-side delay by the variable delay circuit are kept at the first delay specifying value of the first register and the second delay specifying value of the second register, respectively.

Abstract: A digital DLL circuit includes: a first register configured to hold a delay specifying value to specify a delay; a second register configured to specify a correction value for a gate delay inside an LSI; a digitally-controlled variable delay circuit; and a control circuit configured to produce a delay control value to implement control so that a delay by the variable delay circuit is kept at the delay specifying value of the first register. The digital DLL circuit further includes an adder circuit configured to add a gate delay correction value held by the second register to the delay control value output from the control circuit, and output a resultant value to a control input of the variable delay circuit.

Abstract: A logic processing circuit including a plurality of flip-flop including a front stage flip-flop and a rear stage flip-flop, a logic gate circuit network adapted to process data stored in the front stage flip-flop, a result of the process being stored in the rear stage flip-flop, and switching means for switching between a power-on period and a power-off period, the power-on period being a period in which power is being provided to the logic gate circuit network, the power-on period corresponding to either a low-level state period of a clock signal or a high-level state period thereof, the power-off period being a period in which the power is being turned off, the power-off period corresponding to the state period other than the state period corresponding to the power-on period.

Abstract: Off-leak electric current is reduced in the operation mode where a circuit is actually operating. In the state in which the power supply voltage is constantly applied to the front stage flip-flops 11 to 13 and rear stage flip-flops 21 to 23, for example, data held in the flip-flops 11 to 13 at rising of the clock signal CK is processed in a logic gate circuit network 31 to which the supply voltage is applied during a low level period of the clock signal CK, and then, the processed data is held in the flip-flops 21 to 23. In the case where the power supply time to the logic gate circuit network 31 is set to minimum, off-leak electric current of the logic gate circuit network 31 can be reduced.

Abstract: A delay stabilization circuit capable of suppressing a drop in stability of delay or frequency and a cost increase and also able to shorten a design time, and a semiconductor integrated circuit are provided. The delay stabilization circuit includes a passive noise filter configured by a capacitor and a resistor, a variable delay circuit including a logic gate to which power of a power source is supplied through the noise filter, and a feedback control circuit for suppressing delay fluctuation of the variable delay circuit using a clock input from the outside as a reference.

Abstract: A delay stabilization circuit capable of suppressing a drop in stability of delay or frequency and a cost increase and also able to shorten a design time, and a semiconductor integrated circuit are provided. The delay stabilization circuit includes a passive noise filter configured by a capacitor and a resistor, a variable delay circuit including a logic gate to which power of a power source is supplied through the noise filter, and a feedback control circuit for suppressing delay fluctuation of the variable delay circuit using a clock input from the outside as a reference.

Abstract: A method of frame synchronization for serial data transmission is presented herein. A transmitting circuit in a data communication apparatus converts frame data into serial data and transmits the same, and following the serial data, the transmitting circuit transmits frame synchronization data varying several times in the interval from an edge of a clock signal to an edge of the next clock signal; a receiving circuit receives the frame data and detects two or more variations in the same interval to find the end of the frame data, by receiving the serial data from a signal line, serial data is transmitted while carrying out frame synchronization.

Abstract: A method of frame synchronization serial data transmission. A transmitting circuit in a data communication apparatus converts frame data into serial data and transmit the same, and following the serial data, the transmitting circuit transmits frame synchronization data varying several times in the interval from an edge of a clock signal to an edge of the next clock signal; a receiving circuit receives the frame data and detects twice or more variations in the same interval to find out the end of the frame data, by receiving the serial data from a signal lines, serial data is transmitted while carrying out frame synchronization.

Abstract: A method of frame synchronization serial data transmission. A transmitting circuit in a data communication apparatus converts frame data into serial data and transmit the same, and following the serial data, the transmitting circuit transmits frame synchronization data varying several times in the interval from an edge of a clock signal to an edge of the next clock signal; a receiving circuit receives the frame data and detects twice or more variations in the same interval to find out the end of the frame data, by receiving the serial data from a signal lines, serial data is transmitted while carrying out frame synchronization.