GS2971A Datasheet, PDF (64/152 Pages) Gennum Corporation – Integrated audio clock generator

Table 4-12:Data Format Register Codes
YDATA_FORMAT[3:0] or
CDATA_FORMAT[3:0]
0h ~ 05h
Data Format
SDTI
6h
7h
8h
9h
Ah ~ Eh
Fh
SDI
Reserved
TDM
HD-SDTI
Reserved
Non-SMPTE data
format
Remarks
SMPTE 321M, SMPTE 322M,
SMPTE 326M
−
−
SMPTE 346M
−
−
Detected data format is not SMPTE.
LOCKED = LOW.
NOTE: This Data Format register is
invalid in SMPTE_BYPASS mode.
The data format is determined using the following criteria:
• If TRS ID words are detected but no SDTI header or TDM header is detected, then
the data format is SDI
• If TRS ID words are detected and the SDTI header is available then the format is
SDTI
• If TRS ID words are detected and the TDM data header is detected then the format is
TDM video
• No TRS words are detected, but the PLL is locked, then the data format is unknown
NOTE: Two data format sets are provided for HD video rates. This is because the Y and
Cr/Cb channels can be used separately to carry SDTI data streams of different data
formats. In SD video mode, only the Y data format register contains the data, and the C
register is set to Fh (undefined format).
4.15 EDH Detection
4.15.1 EDH Packet Detection
The GS2971A determines if EDH packets are present in the incoming video data and
asserts the EDH_DETECT status according to the SMPTE standard.
EDH_DETECT is set HIGH when EDH packets have been detected and remains HIGH
until EDH packets are no longer present. It is set LOW at the end of the vertical blanking
(falling edge of V) if an EDH packet has not been detected during vertical blanking.
EDH_DETECT can be programmed to be output on the multi-function output port pins.
The EDH_DETECT bit is also available in the host interface.
GS2971A 3Gb/s, HD, SD SDI Receiver
Data Sheet
54311 - 2
September 2012
64 of 152