GX3202 Datasheet, PDF (22/49 Pages) Semtech Corporation – Crosspoint Switch with Trace Equalization and Output De-emphasis

4.2 Serial Data Output
Each of the GX3202 SDI outputs have two on-chip 50Ω single-ended terminations, and
can be programmed to output differential amplitudes of 200mVppd, 400mVppd or
800mVppd when the corresponding VCC_OUT1 or VCC_OUT2 is connected to either
1.2V or 1.8V, or 200mVppd, 400mVppd, 800mVppd, or 1200mVppd when the
corresponding VCC_OUT1 or VCC_OUT2 is connected to 2.5V. The selection of the
output swing is made using the corresponding OUTPUT_SWING_SET[287:0],
MON0_OUTPUT_SWING_SET or MON1_OUTPUT_SWING_SET bits, shown in
Table 4-3.
If the HIGH_OP_V bit is set when either the VCC_OUT1 or VCC_OUT2 supplies are 1.2V
or 1.8V, the 800mVppd swing setting is no longer valid for that output bank. Swing
settings for an output bank connected to a 2.5V supply are unaffected.
Table 4-2: HIGH_OP_V Swing Selection
HIGH_OP_V = 0
HIGH_OP_V = 1
Note
VCC_OUTx
Supply Voltage
(V)
Valid Output Swing
Selection
(mVppd)
Valid Output Swing
Selection
(mVppd)
1.2
200, 400, 800
200, 400
1
1.8
200, 400, 800
200, 400
—
2.5
200, 400, 800
200, 400, 800, 1200
2, 3
NOTES:
1. For an 800mVppd output swing when the corresponding VCC_OUT1 or VCC_OUT2 is connected
to 1.2V, the output must be DC-coupled to a receiving device terminated to 1.2V.
2. When VCC_OUT1 or VCC_OUT2 is set to 2.5V, the HIGH_OP_V bit must be set to enable
1200mVppd swing selection.
Each of the 202 SDI output channels provide independently programmable
de-emphasis, to compensate from 0 to 47 inches (119 cm) of FR4 trace at 3Gb/s. The
selection of the amount of output de-emphasis is made using the corresponding
OUTPUT_DEEMPHASIS[287:0], MON0_OUTPUT_DEEMPHASIS or
MON1_OUTPUT_DEEMPHASIS bits, shown in Table 4-3.
Each output can be independently powered-down by the setting of the corresponding
bit: ACTIVE_POWER_DOWN[287:0], DYNAMIC_POWER_DOWN[287:0] together
with the assigned strobe, MON0_POWER_DOWN, or MON1_POWER_DOWN.
The polarity of the signal at each output can be independently inverted by setting the
corresponding bit: ACTIVE_SIGNAL_INVERT[287:0],
DYNAMIC_SIGNAL_INVERT[287:0] together with the assigned strobe,
MON0_SIGNAL_INVERT, or MON1_SIGNAL_INVERT.
GX3202 202 x 202 3.5Gb/s Crosspoint
Data Sheet
56077 - 1
October 2012
22 of 49
Proprietary & Confidential