EP2SGX30CF780C5N Datasheet, PDF (21/316 Pages) Altera Corporation – Section I. Stratix II GX Device Data Sheet

Stratix II GX Architecture
Differential signaling conventions are shown in Figure 2–9. The
differential amplitude represents the value of the voltage between the
true and complement signals. Peak-to-peak differential voltage is defined
as 2 × (V_HIGH – V_LOW) = 2 × single-ended voltage swing. The common
mode voltage is the average of V_high and V_low.
Figure 2–9. Differential Signaling
Single-Ended Waveform
True
Complement
Differential Waveform
V_high
+- V_OD
V_low
V_OD (Differential)
= V_high − V_low
+V_OD
2 * V_OD
+400
0-V Differential
-V_OD
−400
Programmable Pre-Emphasis
The programmable pre-emphasis module controls the output driver to
boost the high frequency components, and compensate for losses in the
transmission medium, as shown in Figure 2–10. The pre-emphasis is set
statically using the ALT2GXB megafunction or dynamically through the
dynamic reconfiguration controller.
Figure 2–10. Pre-Emphasis Signaling
V_MAX V_MIN
Pre-Emphasis % = ( ^VMAX − 1) × 100
V_MIN
Altera Corporation
October 2007
2–13
Stratix II GX Device Handbook, Volume 1