Abstract: A method for adjusting audio frequency includes steps of: obtaining initial frequency and temporary data storage of audio data input to a buffering unit; performing a first adjustment procedure on initial frequency to obtain a first variation of temporary data storage corresponding to a first change of initial frequency; calculating a first frequency correction amount according to first variation and a first period of first adjustment procedure; adjusting initial frequency into first frequency according to first frequency correction amount; inputting first frequency into buffering unit; performing a second adjustment procedure on first frequency to obtain a second variation of temporary data storage corresponding to a second change of first frequency; calculating a second frequency correction amount according to second variation and a second period of second adjustment procedure, which first period is less than second period; and adjusting first frequency into target frequency according to second frequency co

Abstract: A test system includes a transmitter, capacitor, and receiver. The transmitter includes: an output circuit coupled to the receiver via the capacitor; a transmitting circuit transmitting a predetermined signal to a pad of the output circuit during a first test; a signal generator outputting a first signal and second signal to the pad during a first process and second process of a second test; and a comparator comparing the pad's signal with a reference signal in the first process and second process to determine whether the second test passes. The receiver includes: an input circuit coupled to the transmitter via the capacitor; a switch coupled between the input circuit and a receiving circuit to be conducting in the first test and second process and nonconducting in the first process; and the receiving circuit determining whether the first test passes according to the predetermined signal and assisting the capacitor in discharging.

Abstract: A test system includes a transmitter, capacitor, and receiver. The transmitter includes: an output circuit coupled to the receiver via the capacitor; a transmitting circuit transmitting a predetermined signal to a pad of the output circuit during a first test; a signal generator outputting a first signal and second signal to the pad during a first process and second process of a second test; and a comparator comparing the pad's signal with a reference signal in the first process and second process to determine whether the second test passes. The receiver includes: an input circuit coupled to the transmitter via the capacitor; a switch coupled between the input circuit and a receiving circuit to be conducting in the first test and second process and nonconducting in the first process; and the receiving circuit determining whether the first test passes according to the predetermined signal and assisting the capacitor in discharging.

Abstract: The present disclosure provides a crystal-less clock and data recovery (CDR) circuit and a frequency detection method thereof. The CDR circuit includes a clock generator and a frequency detection module. The clock generator is operable to generate a clock signal. The frequency detection module coupled to the clock generator is configured for outputting a control signal to the clock generator to increase or decrease the frequency of the clock signal according to a data signal received and a transition density.

Abstract: The present disclosure provides a crystal-less clock and data recovery (CDR) circuit and a frequency detection method thereof. The CDR circuit includes a clock generator and a frequency detection module. The clock generator is operable to generate a clock signal. The frequency detection module coupled to the clock generator is configured for outputting a control signal to the clock generator to increase or decrease the frequency of the clock signal according to a data signal received and a transition density.