DK-DEV-4SGX230N Altera, DK-DEV-4SGX230N Datasheet - Page 303

• Manufacturer Part Number: DK-DEV-4SGX230N
• Description: KIT DEVELOPMENT STRATIX IV
• Manufacturer: Altera
• Series: Stratix® IVr
• Type: FPGAr

Specifications of DK-DEV-4SGX230N

• Contents: Development Board, Universal Power Supply, Cables and Software
• Silicon Manufacturer: Altera
• Core Architecture: FPGA
• Core Sub-architecture: Stratix
• Silicon Core Number: EP4S
• Silicon Family Name: Stratix IV GX
• Rohs Compliant: Yes
• For Use With/related Products: EP4SGX230K
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 544-2594

Chapter 8: High-Speed Differential I/O Interfaces and DPA in Stratix IV Devices
Differential Receiver
Figure 8–20. Receiver Datapath in Soft-CDR Mode
Notes to
(1) All disabled blocks and signals are grayed out.
(2) In SDR and DDR modes, the data width from the IOE is 1 and 2 bits, respectively.
(3) The rx_out port has a maximum data width of 10 bits.
February 2011 Altera Corporation
rx_divfwdclk
rx_outclock
Fabric
FPGA
rx_out
Figure
8–20:
f
10
Soft-CDR Mode
The Stratix IV LVDS channel offers soft-CDR mode to support the Gigabit Ethernet
and SGMII protocols. A receiver PLL uses the local clock source for reference.
Figure 8–20
In soft-CDR mode, the synchronizer block is inactive. The DPA circuitry selects an
optimal DPA clock phase to sample the data. Use the selected DPA clock for bit-slip
operation and deserialization. The DPA block also forwards the selected DPA clock,
divided by the deserialization factor called rx_divfwdclk, to the FPGA fabric, along
with the deserialized data. This clock signal is put on the periphery clock (PCLK)
network. When using soft-CDR mode, the rx_reset port must not be asserted after
the rx_dpa_lock is asserted because the DPA will continuously choose new phase
taps from the PLL to track parts per million (PPM) differences between the reference
clock and incoming data.
For more information about periphery clock networks, refer to the
PLLs in Stratix IV Devices
IOE Supports SDR, DDR, or Non-Registered Datapath
(LOAD_EN, diffioclk)
2
Deserializer
DOUT DIN
shows the soft-CDR mode datapath.
IOE
2
Left/Right PLL
3
DOUT DIN
Clock Mux
Bit Slip
(LVDS_LOAD_EN,
LVDS_diffioclk,
chapter.
(Note
rx_outclk)
diffioclk
1), (2),
rx_inclock
(3)
DOUT DIN
Synchronizer
8 Serial LVDS
Clock Phases
LVDS Receiver
3
(DPA_LOAD_EN,
DPA_diffioclk,
rx_divfwdclk)
Stratix IV Device Handbook Volume 1
Retimed
Data
DPA Clock
DPA Circuitry
Clock Networks and
DIN
+
LVDS Clock Domain
DPA Clock Domain
rx_in
8–25