| 摘要 |
<p>A method for combining signals being conveyed across a digital interface (16) is disclosed. In one embodiment, a subharmonic ( f2) of a frequency (f0) is superimposed on asynchronous data. The subharmonic can be used to carry a frequency reference across the digital interface. In another embodiment, a time stamp algorithm is used to carry a time reference from a master circuit (50) to a slave circuit (52) across a digital interface. The transmission delay between the master circuit and slave circuit is measured. The master circuit transmits time correction messages to the slave circuit, based on the time the correction message is transmitted plus the transmission delay. In another embodiment, a reset signal is carried across a digital interface by discontinuing the transfer of a frequency reference for a predetermined time. A lowpass filter (54) can be used at the receiving side of the interface to recognize the absence of the frequency reference and initiate a reset procedure at that side.</p> |
