Patent ID: 9397774
Filing Date: 2016-07-19
CPC Classification: G06F,H04J,H04N

Claim Text:
1. A method of re-timing sampled data in a digital data processing system, the method comprising: receiving input data samples at an input data rate; storing said input data samples in a FIFO buffer having a fill level; forming a loop-filtered measure of said fill level; forming an estimate of the input data rate; controlling the frequency of an output clock in accordance with said loop-filtered measure and said estimate; and outputting data samples from the FIFO buffer at an output data rate determined by the output clock; in which the said estimate is formed from a filtered average of the number of input samples arriving in a fixed time interval, in which the said filtered average is filtered by a variable filter having a characteristic that is varied in dependence on the said loop-filtered measure of the fill level of the said buffer, and in which said characteristic is varied in dependence on the magnitude of an integrated value of the said loop-filtered measure of the fill level of the said buffer.