EP4SE360F35I4 Datasheet, PDF (292/432 Pages) Altera Corporation – This section provides a complete overview of all features relating to the Stratix IV device family, which is the most architecturlly advanced

8–12
Chapter 8: High-Speed Differential I/O Interfaces and DPA in Stratix IV Devices
Differential Transmitter
The load enable (LVDS_LOAD_EN) signal and the diffioclk signal (the clock running at
serial data rate) generated from PLL_Lx (left PLL) or PLL_Rx (right PLL) clocks the load
and shift registers. You can statically set the serialization factor to ×3, ×4, ×6, ×7, ×8, or
×10 using the Quartus II software. The load enable signal is derived from the
serialization factor setting. Figure 8–5 shows a block diagram of the Stratix IV
transmitter.
Figure 8–5. Stratix IV Transmitter ⁽¹⁾, ⁽²⁾
tx_in ₁₀
FPGA
Fabric
tx_coreclock
Serializer 2
IOE
DIN DOUT
IOE supports SDR, DDR, or
Non-Registered Datapath
LVDS Transmitter
tx_out
+
-
3 (LVDS_LOAD_EN, diffioclk, tx_coreclock)
Left/Right PLL
tx_inclock
LVDS Clock Domain
Notes to Figure 8–5:
(1) In SDR and DDR modes, the data width is 1 and 2 bits, respectively.
(2) The tx_in port has a maximum data width of 10 bits.
You can configure any Stratix IV transmitter data channel to generate a
source-synchronous transmitter clock output. This flexibility allows the placement of
the output clock near the data outputs to simplify board layout and reduce
clock-to-data skew. Different applications often require specific clock-to-data
alignments or specific data-rate-to-clock-rate factors. The transmitter can output a
clock signal at the same rate as the data with a maximum frequency of 800 MHz. The
output clock can also be divided by a factor of 1, 2, 4, 6, 8, or 10, depending on the
serialization factor. You can set the phase of the clock in relation to the data at 0° or
180° (edge or center aligned). The left and right PLLs (PLL_Lx and PLL_Rx) provide
additional support for other phase shifts in 45° increments. These settings are made
statically in the Quartus II MegaWizard Plug-In Manager software.
Stratix IV Device Handbook
Volume 1
September 2012 Altera Corporation