Abstract: A crystal oscillator circuit is provided. The crystal oscillator circuit includes an oscillator start-up circuit having a first output terminal and a second output terminal, where the second output terminal outputs a first oscillation signal; and a waveform conversion circuit configured to convert the first oscillation signal to a rectangular wave signal. The crystal oscillator circuit also includes a first current source configured to output a first current to drive the oscillator start-up circuit; and a second current source configured to output a second current, and being connected in parallel with the first current source to jointly drive the oscillator start-up circuit. Further the crystal oscillator circuit includes a pulse generation circuit configured to generate a control pulse signal to control the second current source to output the second current after power on and to stop outputting the second current after a preset time.

Abstract: A bus contention detection circuit includes a delay unit having an input terminal for receiving an output signal of an I/O driver, a duty cycle adjustment unit connected to the delay unit, and a comparison unit having a first input terminal for receiving the output signal, a second terminal for receiving a reference voltage, and an enable terminal for receiving an enable signal of the duty cycle adjustment unit. The enable signal has a rising edge that is delayed relative to a rising edge of the output signal and a falling edge that is aligned with a falling edge of the output signal. The comparison unit compares a voltage level of the output signal with the reference voltage when the enable signal is in a stable voltage state and determine a bus condition in response to a comparison result.

Abstract: A bus contention detection circuit includes a delay unit having an input terminal for receiving an output signal of an I/O driver, a duty cycle adjustment unit connected to the delay unit, and a comparison unit having a first input terminal for receiving the output signal, a second terminal for receiving a reference voltage, and an enable terminal for receiving an enable signal of the duty cycle adjustment unit. The enable signal has a rising edge that is delayed relative to a rising edge of the output signal and a falling edge that is aligned with a falling edge of the output signal. The comparison unit compares a voltage level of the output signal with the reference voltage when the enable signal is in a stable voltage state and determine a bus condition in response to a comparison result.

Abstract: A crystal oscillator circuit is provided. The crystal oscillator circuit includes an oscillator start-up circuit having a first output terminal and a second output terminal, where the second output terminal outputs a first oscillation signal; and a waveform conversion circuit configured to convert the first oscillation signal to a rectangular wave signal. The crystal oscillator circuit also includes a first current source configured to output a first current to drive the oscillator start-up circuit; and a second current source configured to output a second current, and being connected in parallel with the first current source to jointly drive the oscillator start-up circuit. Further the crystal oscillator circuit includes a pulse generation circuit configured to generate a control pulse signal to control the second current source to output the second current after power on and to stop outputting the second current after a preset time.