gs9076 Gennum Corporation, gs9076 Datasheet - Page 20

• Manufacturer Part Number: gs9076
• Description: Sd-sdi Automatic Reclocker With Dual Differential Outputs
• Manufacturer: Gennum Corporation

4.8 Bypass Mode
4.9 Lock and LOS
In Bypass mode, the GS9076 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, the GS9076 will be in Bypass mode.
When AUTOBYPASS is set HIGH, the GS9076 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 DDO0/DDO0 or DDO1/DDO1 will produce invalid data.
The LOCKED signal is an active high output which indicates when the PLL is
locked.
The internal lock logic of the GS9076 includes a system which monitors the
Frequency Acquisition Loop and the Phase Acquisition Loop as well as a monitor
to detect harmonic lock.
The LOS (Loss of Signal) output is an active HIGH output which indicates the
absence of data transitions at the DDIx input. In order for this output to be asserted,
transitions must not be present for a period of t
been asserted, LOS will deassert within t
transition at the DDIx input.
DATA
Figure 4-3: LOS signal timing
NOTE: LOS is sensitive to transitions appearing at the input, and does not
distinguish between transitions caused by input data, and transitions due to noise.
44617 - 1
LOS
January 2008
t
LA
LD
= 0 - 5 us after the appearance of a
LA
= 5 - 10 us. After this output has
GS9076 Data Sheet
t
LD
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