AUTOMATIC REFERENCE SWITCH AND TEST PORT
Original Publication Date: 1992-Dec-01
Included in the Prior Art Database: 2002-Jan-18
BACKGROUND OF THE INVENTION SUMMARY OF THE INVENTION This invention relates to the selection of reference frequencies. Many electronic machines use an internally generated reference frequency for their operation and it is sometimes possible to lock this reference to an exter- nal reference. This is usually done through a port which may be used to either monitor the internal reference or used to inject the external reference.