GS1510 Gennum Corporation, GS1510 Datasheet - Page 9

• Manufacturer Part Number: GS1510
• Description: Hd-linx (tm) THDTV Serial Digital Deformatter
• Manufacturer: Gennum Corporation

3. DETAILED DESCRIPTION
3. DETAILED DESCRIPTION
3. DETAILED DESCRIPTION
3. DETAILED DESCRIPTION
3.1 DATA INPUT AND OUTPUTS
Data enters and exits the device on the rising edge of
PCLK_IN as shown in Figures 1 and 2. This data can be
scrambled or unscrambled and framed or unframed.
3.2 DESCRAMBLER AND FRAMER
Both the descrambler and framer can be enabled or
disabled independently of each other to allow the input to
remain scrambled or unscrambled. If the data is
unscrambled, it can be word aligned (framed) or passed
through unaltered.
3.3 STANDARDS INDICATION
VD_STD[3:0] indicates the standard that the device has
detected. The states of VD_STD[3:0] are shown in the
following standards indication tables.
Progressive Scan Standards Indication
Interlaced Standards Indication
GENNUM CORPORATION
(VD_STD[3]=0)
(VD_STD[3]=1)
VD_STD[3:0]
VD_STD[3:0]
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
1100
1101
1110
1111
720p (60 & 60/1.001Hz → L/M) [SMPTE296M]
Reserved
1080p (30 & 30/1.001Hz → G/H)
[SMPTE274M]
Reserved
1080p (25Hz → I) [SMPTE274M]
Reserved
1080p (24 & 24/1.001Hz → J/K) [SMPTE274M]
Unknown Progressive with F = 0 always.
1080i (30 & 30/1.001Hz → D/E) [SMPTE274M]
Reserved
1080i (25Hz → F) [SMPTE274M]
Reserved
1080i (25Hz → C) [SMPTE295M]
Reserved
1035i (30 & 30/1.001Hz → A/B) [SMPTE260M]
Unknown Interlaced with F switching 0/1
DESCRIPTION
DESCRIPTION
9
Note the following in the preceding tables:
See Table 1 for more specific details on the source format
parameters.
3.4 FLY WHEEL OPERATION
The flywheel logic will check the incoming video data for
valid video lines. If the incoming data represents a valid
line, the flywheel remains in sync with the incoming data. If
the incoming data represents an invalid line, the flywheel
will use the stored timing information for the past valid line
to generate the output HVF timing signals until three (3)
consecutive lines having identical timing are detected. In
this case, the new timing information will be saved and the
flywheel operation is updated to this new timing.
Mismatches between the HVF information decoded from
the data stream and that indicated by the flywheel will
trigger the EAV_ERR and SAV_ERR signals as shown in
Figure 3. HVF output timing is shown in Figure 2.
3.5 AUTOMATIC SWITCH LINE LOCK HANDLING
The automatic switch line lock is based on the assumption
that the switching of video sources will only cause the H
signal to be out of alignment whereas V and F signals
remain in sync; i.e. switching between video sources of the
same format. Therefore, when in the automatic switch line
lock mode (FAST_LOCK transitions for low to high), the
flywheel positive H signal transition will align with the
detected positive H signal transition. Timing for the
FAST_LOCK signal is shown in Figure 5.
SMPTE260M is 1125 lines/frame
SMPTE274M is 1125 lines/frame
SMPTE295M is 1250 lines/frame
SMPTE296M is 750 lines/frame
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