EP3C16F256I7N Altera, EP3C16F256I7N Datasheet - Page 132

• Manufacturer Part Number: EP3C16F256I7N
• Description: Cyclone III
• Manufacturer: Altera

7–8
Figure 7–2. Cyclone III Device Family LVDS Interface with True Output Buffer on the Left and Right I/O Banks
Figure 7–3. LVDS Interface with External Resistor Network on the Top and Bottom I/O Banks
Note to
(1)
BLVDS I/O Standard Support in the Cyclone III Device Family
Cyclone III Device Handbook, Volume 1
R
S
Transmitting Device
Figure
= 120
Ω;
7–3:
R
P
= 170
Cyclone III Device Family
txout -
txout +
Ω
LVDS Transmitter
Designing with LVDS
Cyclone III device family I/O banks support LVDS I/O standard. The left and right
I/O banks support true LVDS transmitters. On the top and bottom I/O banks, the
emulated LVDS transmitters are supported using two single-ended output buffers
with external resistors. One of the single-ended output buffers is programmed to have
opposite polarity. The LVDS receiver requires an external 100-Ω termination resistor
between the two signals at the input buffer.
Figure 7–2
LVDS output and input buffers.
Figure 7–3
LVDS using two single-ended output buffers and external resistors.
The BLVDS I/O standard is a high-speed differential data transmission technology
that extends the benefits of standard point-to-point LVDS to multipoint configuration
that supports bidirectional half-duplex communication. BLVDS differs from standard
LVDS by providing a higher drive to achieve similar signal swings at the receiver
while loaded with two terminations at both ends of the bus.
Emulated
50 Ω
50 Ω
100 Ω
rxin +
rxin -
shows a point-to-point LVDS interface using Cyclone III device family true
shows a point-to-point LVDS interface with Cyclone III device family
Input Buffer
Resistor Network
R S
R S
Cyclone III Device Family
R P
Family Logic
Cyclone III
Chapter 7: High-Speed Differential Interfaces in the Cyclone III Device Family
Device
Array
Output Buffer
50 Ω
50 Ω
100 Ω
txout +
txout -
50 Ω
50 Ω
LVDS Receiver
© December 2009 Altera Corporation
rxin +
rxin -
High-Speed I/O Standards Support
(Note 1)
100 Ω
Receiving Device