I/O Standards Support
You can use I/O pins and internal logic to implement a high-speed I/O
receiver and transmitter in Cyclone II devices. Cyclone II devices do not
contain dedicated serialization or deserialization circuitry. Therefore,
shift registers, internal global phase-locked loops (PLLs), and I/O cells
are used to perform serial-to-parallel conversions on incoming data and
parallel-to-serial conversion on outgoing data.
This section provides information on the I/O standards that Cyclone II
devices support.
I/O Standards
Support
LVDS Standard Support in Cyclone II Devices
The LVDS I/O standard is a high-speed, low-voltage swing, low power,
and general purpose I/O interface standard. The Cyclone II device meets
the ANSI/TIA/EIA-644 standard.
I/O banks on all four sides of the Cyclone II device support LVDS
channels. See the pin tables on the Altera web site for the number of LVDS
channels supported throughout different family members. Cyclone II
LVDS receivers (input) support a data rate of up to 805 Mbps while LVDS
transmitters (output) support up to 640 Mbps. The maximum internal
clock frequency for a receiver and for a transmitter is 402.5 MHz. The
maximum input data rate of 805 Mbps and the maximum output data
rate of 640 Mbps is only achieved when DDIO registers are used. The
LVDS standard does not require an input reference voltage; however, it
does require a 100-Ωtermination resistor between the two signals at the
input buffer.
f
For LVDS data rates in Cyclone II devices with different speed grades,
see the DC Characteristics & Timing Specifications chapter of the Cyclone II
Device Handbook.
Table 11–1 shows LVDS I/O specifications.
Table 11–1. LVDS I/O Specifications (Part 1 of 2)
Note (1)
Symbol Parameter Condition
Min
1.15
2.375
250
Typ
1.2
2.5
Max
1.25
2.625
600
Units
V
VCCINT
Supply voltage
I/O supply voltage
VCCIO
VOD
V
Differential output voltage RL = 100 Ω
mV
mV
ΔVOD
Change in VOD between RL = 100 Ω
50
H and L
VOS
Output offset voltage
RL = 100 Ω
1.125
1.25
1.375
V
11–4
Altera Corporation
February 2007
Cyclone II Device Handbook, Volume 1
ALTERA [ ALTERA CORPORATION ]
