Patent ID: 8090070
Filing Date: 2012-01-03
Classification: G06F,H03L,H04J,H04L

Abstract:
1. A synchronizing device for real-time USB audio data transmission, comprising: a first adder unit receiving a plurality of start-of-frame signals and obtaining a summation of the start-of-frame signals; a start-of-frame countdown unit using a phase-locked signal as a clock after receiving a first start-of-frame signal of the start-of-frame signals to countdown from an initial value until the start-of-frame countdown unit receives a next start-of-frame signal to issue a clock number difference and store the initial value in the start-of-frame countdown unit; a phase-locked loop circuit receiving a first clock signal to issue the phase-locked signal; a frequency divider receiving a second clock signal to determine a frequency dividing factor to be applied to the second clock signal according to a frequency dividing factor selection signal and control the timing for frequency dividing according to a calibrating pulse signal to issue the first clock signal; a second adder unit summing up the start-of-frame signal summation, the clock number difference and a time difference accumulated value to issue a time difference accumulated input value; a third adder unit receiving the time difference accumulated input value to issue the time difference accumulated value and the time difference accumulated input value; a fourth adder unit summing up the clock number difference, the time difference accumulated input value and an adjusted clock number signal to issue an adjusted clock number signal accumulated value; a frame calibrating register unit receiving the adjusted clock number signal accumulated value to issue the adjusted clock number signal; a fifth adder unit summing up the adjusted clock number signal and the time difference accumulated input value to issue an adjusted clock number input value; a calibrating mapping unit receiving the adjusted clock number input value to issue an adjusted number value and the frequency dividing factor selection signal; and a calibrating pulse generating unit receiving the adjusted number value to issue the calibrating pulse signal.