Grass Valley 8936 - Manual (Page 16)

10 8936 Instruction Manual
8936 Auto Reclocking DA
Functional Description
Refer to the simplified block diagram in Figure 8 while reading the fol-
lowing functional description.
Figure 8. 8936 Simplified Block Diagram
The Cable Equalizer block automatically equalizes the input signal to com-
pensate for cable loss up to 300 meters of 8281 cable (or equivalent) oper-
ating at
270 Mb/s. The signal goes to the Input Signal Monitor block which lights
an LED when the EQ circuit reaches its limits of equalization (310 meters of
8281 cable operating at 270 Mb/s).
The Cable Equalizer block also feeds the Deserializer that contains a phase
lock loop which locks to the frequency of the incoming signal. The input
signal is then reclocked to the clock generated by the phase lock loop. The
Deserializer also deserializes the incoming signal to form a ten-bit parallel
data stream and a parallel data clock. The parallel data clock has a fre-
quency equal to one tenth of the incoming signal rate.
An Output Driver then amplifies and distributes the reclocked serial digital
video signal to eight BNC outputs.
EQ Warning LED
Input
Outputs
8
Cable
Equalizer
Output
Drivers
Deserializer
Input Signal
Monitoring
Parallel Clock
Frequency
Detection
TRS
Detection
PLD
Logic
Power Supply
Monitoring
5V Switching
Regulator
2
10
4
Format &Signal
Present LEDs
Health Monitor
EQ Warning
(Adjustment)
AFC
Adjustment
DIP
Switch
8110-01