EB-GS2985-S
Evaluation Board User Guide
52246 - 2
July 2009
18 of 25
Functionality of Buttons
Functionality of Knobs
Offset Correction
E
q
ualizer offset correction enable
Attenuation
Input attenuation enable. Should be enabled
for input signals above 1Vpp differential
Polarity Invert
Data polarity invert
Crystal Buffer
Crystal buffer disable
Power Down
Chip powers down when asserted
LOS Auto Mute
When enabled the output will automatically
mute if Loss of Signal is HIGH
Read
Read DATA from a GS2985 register (x00 -
x0D)
Write
Write DATA to a GS2985 register (x00 - x0D)
ReadStatus
Reads status of outputs SS0, SS1, LOS, SD/HD,
Locked
• SS1 and SS0 indicate the selected data
rate (00 - Reserved, 01 - 270Mbs, 10 -
1485Mbs, 11 - 2970Mbs)
• LOS indicates when a Loss of Signal
occurs
• SD/HD indicates when SD mode is
selected
• LOCKED indicates when the PLL is
locked
Reset IC
Resets the GS2985
EQ Gain
E
q
ualizer gain setting
DE Setting
De-emphasis boost amplitude control (0 =
lowest setting, 7 = highest setting)
Output Swing
Sets the output amplitude (400mV
swing/800mV swing)
LOS Detection Method
Legacy = edge detection method, New =
signal strength detection method, Dual =
combination of edge detection and signal
strength
LOS Threshold Sensitivity
LOS Threshold Adjust. 0 = least sensitive,
3 = most sensitive
