A multi-bit gray code generation circuit includes: a zeroth bit gray code generation circuit configured to generate a gray code corresponding to a bit 0 of a multi-bit gray code; and a plurality of gray code generation circuits each configured to generate a gray code corresponding to each bit higher than the bit 0 of the multi-bit gray code. Each of the plurality of gray code generation circuits is constituted by a plurality of flip-flop circuits. An output of a flip-flop circuit in the previous stage is input to a flip-flop circuit of the next stage. An output of a flip-flop circuit of the final stage is inverted and held by a flip-flop circuit of the first stage. An output of one of the plurality of flip-flop circuits is output as a gray code corresponding to each bit.

Techniques are described for implementing counter architectures to support high-speed, high-resolution pixel conversions, such as for CMOS image sensor applications. Embodiments implement a counter block that uses loadable true-signal-phase-clocking (L-TSPC) flops for at least a portion of the counter flops. Some embodiments support efficient two-phase pixel conversion by integrating counting, subtraction, and shifting out in the counter. For example, embodiments can perform a first high-speed pixel conversion phase to obtain a first conversion count. Prior to a second phase, the initial counter can be pre-subtracted by the amount of the first conversion count. Embodiments can then perform a second high-speed pixel conversion phase to obtain a second conversion count. As the second conversion count already has the first conversion count pre-subtracted, the second conversion count represents the final two-phase conversion result. Embodiments can read out this final two-phase conversion result as a digital output of the counter.

Techniques are described for implementing counter architectures to support high-speed, high-resolution pixel conversions, such as for CMOS image sensor applications. Embodiments implement a counter block that uses loadable true-signal-phase-clocking (L-TSPC) flops for at least a portion of the counter flops. Some embodiments support efficient two-phase pixel conversion by integrating counting, subtraction, and shifting out in the counter. For example, embodiments can perform a first high-speed pixel conversion phase to obtain a first conversion count. Prior to a second phase, the initial counter can be pre-subtracted by the amount of the first conversion count. Embodiments can then perform a second high-speed pixel conversion phase to obtain a second conversion count. As the second conversion count already has the first conversion count pre-subtracted, the second conversion count represents the final two-phase conversion result. Embodiments can read out this final two-phase conversion result as a digital output of the counter.

The power of a semiconductor device is reduced. The semiconductor device includes a latch circuit composed of a dynamic circuit. The latch circuit includes a first circuit having a decoding function, a plurality of capacitors, a plurality of clock input terminals, a signal input terminal, a first output terminal, and a second output terminal. In a period during which “H” is supplied to a first clock signal, the potential of the first capacitor is updated on the basis of the results of decoding performed by the first circuit. In a period during which “H” is supplied to a second clock signal, the potential of the second capacitor is updated on the basis of the potential of the first capacitor, and the potential of the second capacitor is supplied as a first output signal to the first output terminal. In a period during which “H” is supplied to a third clock signal, the potential of the third capacitor is updated on the basis of the potential of the second capacitor, and the potential of the third capacitor is supplied as a second output signal to the second output terminal.

A buffer circuit, a frequency dividing circuit, and a communications device are disclosed. The buffer circuit includes a buffer, a first control circuit, and a second control circuit. The buffer is coupled to a frequency divider, and the buffer is configured to receive a first signal output by the frequency divider, and output a fourth signal by using an output terminal of the buffer circuit when driven by the first signal, where the first signal is obtained by the frequency divider by performing frequency division on a group of differential signals, and the differential signals include a second signal and a third signal. The first control circuit is configured to perform delay control on a rising edge of the fourth signal based on the second signal. The second control circuit is configured to perform delay control on a falling edge of the fourth signal based on the third signal.

A multi-bit gray code generation circuit includes: a zeroth bit gray code generation circuit configured to generate a gray code corresponding to a bit 0 of a multi-bit gray code; and a plurality of gray code generation circuits each configured to generate a gray code corresponding to each bit higher than the bit 0 of the multi-bit gray code. Each of the plurality of gray code generation circuits is constituted by a plurality of flip-flop circuits. An output of a flip-flop circuit in the previous stage is input to a flip-flop circuit of the next stage. An output of a flip-flop circuit of the final stage is inverted and held by a flip-flop circuit of the first stage. An output of one of the plurality of flip-flop circuits is output as a gray code corresponding to each bit.

A multi-bit gray code generation circuit includes: a zeroth bit gray code generation circuit configured to generate a gray code corresponding to a bit 0 of a multi-bit gray code; and a plurality of gray code generation circuits each configured to generate a gray code corresponding to each bit higher than the bit 0 of the multi-bit gray code. Each of the plurality of gray code generation circuits is constituted by a plurality of flip-flop circuits. An output of a flip-flop circuit in the previous stage is input to a flip-flop circuit of the next stage. An output of a flip-flop circuit of the final stage is inverted and held by a flip-flop circuit of the first stage. An output of one of the plurality of flip-flop circuits is output as a gray code corresponding to each bit.

A system and method for efficiently generating clock signals are described. In various implementations, an integrated circuit includes multiple clock frequency dividers both at its I/O boundaries and across its die. A clock frequency divider utilizes a first clock divider and a second clock divider that receive input clock signals with an initial phase difference between them. The first clock divider and the second clock divider generate output clock signals that have frequencies that are a fraction of the frequencies of the received input clock signals. The second clock divider uses a combined multiplexer and flip-flop (combined mux-flop) circuit. The combined mux-flop circuit receives a reset signal that is asserted asynchronously with respect to an input clock signal received by the second clock divider. The second clock divider generates an output clock signal that has the initial phase difference with an output clock signal of the first clock divider.

Systems, devices, and methods related to frequency converter arrangements are provided. For example, a frequency converter arrangement converts a first signal centered at a first frequency to a second signal centered at a second frequency different from the first frequency. The frequency converter arrangement includes local oscillator (LO) circuitry and in-phase, quadrature-phase (IQ) mixer circuitry coupled to the LO circuitry. The LO circuitry includes duty cycle correction circuitry to adjust a duty cycle of a pair of input clock signals. The duty cycle correction circuitry includes coarse tuning circuitry responsive to a digital calibration code, and analog tuning loop circuitry. The LO circuitry further includes quadrature divider circuitry coupled to an output of the duty cycle correction circuitry, where the quadrature divider circuitry generates an in-phase LO signal and a quadrature-phase LO signal from a pair of output clock signals at outputs of the duty cycle correction circuitry.

Systems, devices, and methods related to frequency converter arrangements are provided. For example, a frequency converter arrangement converts a first signal centered at a first frequency to a second signal centered at a second frequency different from the first frequency. The frequency converter arrangement includes local oscillator (LO) circuitry and in-phase, quadrature-phase (IQ) mixer circuitry coupled to the LO circuitry. The LO circuitry includes duty cycle correction circuitry to adjust a duty cycle of a pair of input clock signals. The duty cycle correction circuitry includes coarse tuning circuitry responsive to a digital calibration code, and analog tuning loop circuitry. The LO circuitry further includes quadrature divider circuitry coupled to an output of the duty cycle correction circuitry, where the quadrature divider circuitry generates an in-phase LO signal and a quadrature-phase LO signal from a pair of output clock signals at outputs of the duty cycle correction circuitry.