Figure 5-12: Differential V
OD
This figure shows the V
OD
of the differential LVDS output.
Single-Ended Waveform
Positive Channel (p)
Negative Channel (n)
Ground
Differential Waveform
p - n = 0 V
V
CM
V
OD
V
OD
V
OD
V
OD
(diff peak - peak) = 2 x V
OD
(single-ended)
Table 5-27: Quartus II Software Assignment Editor—Programmable V
OD
This table lists the assignment name for programmable V
OD
and its possible values in the Quartus II software
Assignment Editor.
Assignment (Default setting in bold)
Field
tx_out
To
Programmable Differential Output Voltage (V
OD
)
Assignment name
00 (low), 01 (medium), 10 (high)
Allowed values
Related Information
Programmable IOE Features in Cyclone V Devices
on page 5-29
I/O Pins Features for Cyclone V Devices
on page 5-33
on page 5-33
on page 5-34
Open-Drain Output
The optional open-drain output for each I/O pin is equivalent to an open collector output. If it is configured
as an open drain, the logic value of the output is either high-Z or logic low.
Use an external resistor to pull the signal to a logic high.
Bus-Hold Circuitry
Each I/O pin provides an optional bus-hold feature that is active only after configuration. When the device
enters user mode, the bus-hold circuit captures the value that is present on the pin by the end of the
configuration.
Altera Corporation
I/O Features in Cyclone V Devices
5-33
I/O Pins Features for Cyclone V Devices
CV-52005
2014.01.10