EP1SGX10C Datasheet, PDF (18/262 Pages) Altera Corporation – StratixGX FPGA Family

Stratix GX FPGA Family
Figure 9. V_OD Differential
Single-Ended Waveform
±V_OD
Differential Waveform
+V_OD
V_OD (Differential)
= V_A − V_B
V_OD (Differential)
V_A
V_B
VOCM + ^{VA − VB}
2
VOCM
− V_OD
VOCM −
V_A − V_B
2
Programmable Pre-Emphasis
The programmable pre-emphasis module controls the output driver to
boost the high frequency components, to compensate for losses in the
transmission medium, as shown in Figure 10. The pre-emphasis can be
dynamically or statically set. There are five possible pre-emphasis
settings (1 through 5), with 5 being the highest and 0 being no
pre-emphasis.
Figure 10. Programmable Pre-Emphasis Model
18
Preliminary
V_CM
V_PP
V_S
V_S(p-p) V_PP(p-p)
Bit
Bit
Time
Time
Pre-emphasis percentage is defined as V_PP/V_S – 1, where V_PP is the
differential emphasized voltage (peak-to-peak) and V_S is the differential
steady-state voltage (peak-to-peak).
Altera Corporation