GS1535B Gennum Corporation, GS1535B Datasheet - Page 21

• Manufacturer Part Number: GS1535B
• Description: Multi-rate Sdi Automatic Reclocker
• Manufacturer: Gennum Corporation

4.8 Bypass Mode
4.9 DVB-ASI Operation
In Manual mode, the SS[2:0] pins become inputs and the data rate can be
programmed by the application layer. In this mode, the search algorithm is disabled
and the PLL will only lock to the data rate selected.
Table 4-2
Manual mode) or the data rate that the PLL has locked to (in Auto mode).
Table 4-2: Data Rate Indication/Selection Bit Pattern
In Bypass mode, the GS1535B/9065B passes the data at the inputs directly to the
outputs. There are two pins that control the bypass function: BYPASS and
AUTOBYPASS.
When BYPASS is set HIGH by the application layer, the GS1535B/9065B will be
in Bypass mode.
When AUTOBYPASS is set HIGH by the application layer, the GS1535B/9065B
will be configured to enter Bypass mode only when the PLL has not locked to a data
rate. When BYPASS is set HIGH, AUTOBYPASS will be ignored.
When the PLL is not locked, and both BYPASS and AUTOBYPASS are set LOW,
the serial digital output DDO/DDO will produce invalid data.
The GS1535B/9065B will also re-clock DVB-ASI at 270 Mb/s. When reclocking
DVB-ASI data set the ASI/177 pin HIGH to prevent a false lock to 177Mb/s. If
ASI/177 is not set HIGH, a false lock may occur since there is a harmonic present
in idle patterns (K28.5) which is very close the 177 Mb/s data rate (EIC 1179). Note
that setting the ASI/177 pin HIGH will disable the 177 Mb/s search when the device
is in Auto mode, consequently the GS1535B/9065B will not lock to that data rate.
40066 - 0
* This setting only applies to the GS1535B. For the GS9065B, when AUTO/MAN is LOW, the pin
settings SS[0:2] = 101 will be ignored by the device.
shows the SS[2:0] pin settings for either the data rate selected (in
August 2006
SS[2:0]
101*
000
001
010
011
100
GS1535B / GS9065B Preliminary Data Sheet
Data Rate (Mb/s)
1485/1483.5
143
177
270
360
540
21 of 27