Specifications

Uncalibrated OCT (Output)
I/O Standard
R
S
(Ω)
25Differential SSTL-15 Class II
50Differential 1.8 V HSTL Class I
25Differential 1.8 V HSTL Class II
50Differential 1.5 V HSTL Class I
25Differential 1.5 V HSTL Class II
50Differential 1.2 V HSTL Class I
25Differential 1.2 V HSTL Class II
Driver-impedance matching provides the I/O driver with controlled output impedance that closely matches
the impedance of the transmission line. As a result, you can significantly reduce signal reflections on PCB
traces.
If you select matching impedance, current strength is no longer selectable.
Figure 5-12: R
S
OCT Without Calibration
This figure shows the R
S
as the intrinsic impedance of the output transistors.
V
CCIO
R
S
R
S
GND
Z
0
= 50 Ω
Driver
Series Termination
Receiving
Device
Related Information
On-Chip I/O Termination in Cyclone V Devices on page 5-33
R
S
OCT with Calibration in Cyclone V Devices
The Cyclone V devices support R
S
OCT with calibration in all banks.
Table 5-30: Selectable I/O Standards for R
S
OCT With Calibration
This table lists the output termination settings for calibrated OCT on different I/O standards.
Calibrated OCT (Output)
I/O Standard
RZQ (Ω)
R
S
(Ω)
(11)
10025/503.0 V LVTTL/3.0 V LVCMOS
(11)
Final values are pending silicon characterization.
Altera Corporation
I/O Features in Cyclone V Devices
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5-35
R
S
OCT with Calibration in Cyclone V Devices
CV-52005
2013.06.21