8-12
Clocks are synchronized* when
- They are in agreement as to the time, or
- Output signals or data streams agree in phase, or
- Sync patterns are in alignment
 
Clocks/oscillators are syntonized** when
- Oscillators have the “same” frequency (the output   signals need not be in phase)
- Clocks run at the same rate (the internal oscillators   need not be of the same frequency)
*  Chron è time
** Tone  è frequency
·
Synchronization, Syntonization
   Wristwatch examples: a wristwatch is compared to a time standard, e.g., to the time at www.time.gov, and is found to be 10 seconds off.  When the time shown by the wristwatch is adjusted to that of the standard, the watch is synchronized.  When the wristwatch is compared again a month later, it is found to be off by 30 seconds.  The wristwatch is taken to a watchmaker who finds that the frequency of the internal oscillator is incorrect.  He adjusts the frequency to the correct value, i.e., to 32,768.0000 Hz, using a frequency standard (e.g., a GPS disciplined oscillator).  At that point, the watch is syntonized to the watchmaker’s frequency standard.  After the watch is disconnected, the syntonization will last for a finite amount of time (that time depends on the allowed frequency offset.).  When two oscillators are frequency locked, they will remain syntonized as long as they remain locked.
   In the slide, “in agreement,” “same”… mean that they are within an acceptable or specified range of each other.