User's Manual
6. CLOCKING
All components within a digital audio system must reference to the same master
clock to ensure that they run synchronously. The multiverter can use any of the
incoming interfaces as clock source, or alternatively it can act as clock master
using its internal, high-quality clock synthesizer.
If a common clock is not possible (e.g. when incoming data
has a different sample rate), the optional
ASRC module
can be
used to convert the data to the multiverter's main clock.
6.1.
ClockShield
The multiverter's unique
ClockShield
feature allows the device to run up to one
second (!) without a master clock signal. This makes the multiverter very robust
against disturbances, glitches and dropouts in the clocking system.
How it works:
When the clock signal is lost, the multiverter's clock continues to run for up to
one second, at the frequency which it has been locked to when the clock was
valid. During that period, audio processing continues as before.
When the clock signal is re-applied, re-synchronization takes place to ensure
perfect bit-wise alignment of data and clock. To avoid pops and clicks, all audio
signals are soft-muted before the re-sync happens, and are soft unmuted
directly after re-sync. The whole process takes only a few milliseconds and
produces only minimal artifacts, often not even audible.
ClockShield
is supported on all interfaces, but works best
when the multiverter is clocked from the BNC wordclock
input.
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