Patent ID: 7450678
Filing Date: 2008-11-11
Classification: H03H

Abstract:
1. An asynchronous signal input apparatus comprising: a storage section that can successively store input data while the stored input data are successively read out such that a remaining data amount of the input data stored in the storage section may temporally vary around a predetermined target data amount; a write control section that successively writes the input data into the storage section in response to an input clock signal having a first frequency; a remaining data amount detection section that detects the remaining data amount of the input data stored in the storage section; a vector detection section that detects a temporal variation of the remaining data amount of the input data stored in the storage section; a loop filter section that generates a correction number based on both of the remaining data amount detected by the remaining data amount detection section and the temporal variation of the remaining data amount detected by the vector detection section, and that generates frequency control information based on the correction number; a read signal generation section that generates a read signal composed of a sequence of pulses occurring in synchronization with an output clock signal having a second frequency, such that an occurrence number of pulses per time is dynamically regulated according to the frequency control information; and a read control section that successively reads out the input data from the storage section in response to the sequence of pulses of the read signal regulated by the read signal generation section, so that the remaining data amount of the input data in the storage section converges to the predetermined target data amount.