GS1531 Datasheet, PDF (27/49 Pages) Gennum Corporation – GS1531 HD-LINX-TM II Multi-Rate Serializer

GS1531 Data Sheet
4.4 DVB-ASI mode
The GS1531 is said to be in DVB-ASI mode when the SMPTE_BYPASS pin is set
LOW and the DVB_ASI and SD/HD pins are set HIGH.
In this mode, all SMPTE processing functions are disabled, and the 8-bit transport
stream data will be 8b/10b encoded prior to serialization.
4.4.1 Control Signal Inputs
In DVB-ASI mode, the DIN19 and DIN18 pins will be configured as DVB-ASI
control signals INSSYNCIN and KIN respectively.
When INSSYNCIN is set HIGH, the device will insert K28.5 sync characters into
the data stream. This function is used to assist system implementations where the
GS1531 may be preceded by an external data FIFO. Parallel DVB-ASI data may
be clocked into the FIFO at some rate less than 27MHz. The INSSYNCIN input
may then be connected to the FIFO empty signal, thus providing a means of
padding up the data transmission rate to 27MHz. See Figure 4-3.
NOTE: 8b/10b encoding will take place after K28.5 sync character insertion.
KIN should be set HIGH whenever the parallel data input is to be interpreted as any
special character defined by the DVB-ASI standard (including the K28.5 sync
character). This pin should be set LOW when the input is to be interpreted as data.
NOTE: When operating in DVB-ASI mode, DIN[9:0] become high impedance.
TS
8
KIN
WRITE_CLK
<27MHz
READ CLK
=27MHz
FIFO
CLK_IN
FE
CLK_OUT
AIN ~ HIN
8
KIN
INSSYNCIN
PCLK = 27MHz
GS1531
SDO
SDO
Figure 4-3: DVB-ASI FIFO Implementation using the GS1531
30573 - 4 July 2005
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