GS2970 Datasheet, PDF (44/145 Pages) Semtech Corporation – 3Gb/s, HD, SD SDI Receiver Complete with SMPTE Audio and Video Processing

4.10.3 Switch Line Lock Handling During Level B to Level A Conversion
When 3G data is detected by the GS2970, and Level B to Level A conversion is enabled,
the device only supports a limited phase offset between two synchronous video sources
if a synchronous switch is implemented.
If the synchronous switch point results in an “extended” active video period, the GS2970
only re-synchronizes to the following TRS ID if the phase difference between the two
sources is less than or equal to 10μs. If the phase difference is greater than 10μs, the
GS2970 takes one additional line to re-synchronize. In this case, the user may observe a
missing H pulse on the line following the switch line, on the H timing output.
NOTE: This 10μs constraint is only valid when Level B to Level A conversion is enabled,
and only when the synchronous switch point results in an extended active video area.
Table 4-7: Switch Line Position for Digital Systems
System
1125
750
Frame Rate
& Structure
60/P
50/P
60/I
50/I
30/P
25/P
24/P
30/PsF
25/PsF
24/PsF
60/P
50/P
30/P
25/P
24/P
Pixel Structure
1920x1080
4:2:2
1280x720
4:2:2
Signal
Standard
Parallel
Interface
274M + RP211
274M + RP211
274M + RP211
274M + RP211
274M + RP211
274M + RP211
274M + RP211
274M + RP211
274M + RP211
274M + RP211
296M
296M
296M
296M
296M
Serial
Interface
292
292
Line No.
7
7/569
7
7
GS2970 3Gb/s, HD, SD SDI Receiver Complete with
SMPTE Audio and Video Processing
Data Sheet
47478 - 4
September 2012
44 of 145