User manual
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differentiation if the boards will be integrated into a Merging Workstation or not. The jumper will be present but only attached to one
pin of the JP4 connector.
Consequently, all the chain process will be drastically simplified, involving only the final assembly department and thus, avoiding any
future problems.”
9.1.2 WCKIO (Old CVS2In)
This connector can be used, under software control, in 2 modes: Wordclock IN or Wordclock OUT.
When software configured as a WCK Input it accepts an external Wordclock reference signal between 0.2 and 5 Vp-p. When software
configured as a WCK Output it provides a 5 V TTL-compatible signal with 22-Ohm output impedance.
For Mykerinos-X only:
A 75Ohm termination can be applied on this signal via software configuration.
For Mykerinos only:
Note: whenever used with a Wordclock signal (either Input or Output), do not terminate (JP5 open) on Mykerinos and on the
Video/TC bracket (This is the default factory settings).
Note, that historically, this connector was able to input a Video signal, as well. The following modification has been made, dated
from November 2004: The Video input feature has been removed from CVS2In/WCK signal. The Wordclock I/O capability
remains unchanged. This modification applies to the following Mykerinos boards: MB1 S/N 12600 - … and MB5 S/N 16150-16759
and 16803 - ….
See below an extract of the ECO MYK011B for a technical detailed explanation:
“
When too high a voltage is applied to the Video 2 input (CVS2IN-WCKI/O), the Video sub-system of the Mykerinos card may enter into an unstable
state (latch up) and subsequently corrupt the proper decoding of the Video 1 Input signal (CVS1IN) as well as the Video Output signal (CVSOUT).
This is specifically the case when CVS2IN is used as a word clock I/O. The Video/TC handling sub-unit on the Mykerinos card may be triggered to
enter this latch-up state with as little as a full 5 Volt p-p Wordclock signal applied.
To resolve this issue permanently, the solution is to physically remove the path linking the CVS2IN-WCKI/O to the Video/TC circuitry and
disconnect this input from the Video sub-system by removing the C127 capacitor to prevent any signal to enter into the Time code chip (U10). This
modification does not prevent to use the Word clock I/O feature but removes the possibility to use the CVS2IN-WCKI/O as a secondary Video/VITC
input
”
9.1.3 CVS OUT
This signal outputs the composite video signal coming from CVS1IN only.
For Mykerinos only:
This signal may additionally carry a VITC and/or a time code "burn-in" video insert generated by Mykerinos.
Note: CVSOUT provides a monitoring quality video output only and is not intended to be used as a loop through “black burst”
output.
9.1.4 LTC IN
LTC IN is a symmetrical input signal. It accepts an external SMPTE/EBU time code signal between 0.2 and 5 Vp-p.
9.1.5 LTC OUT
LTC OUT is an unbalanced output signal. The output voltage level can be software adjusted from 0V to 2.5V p-p.