On-Chip Series Termination Without Calibration - Altera Cyclone IV Device Handbook

6–10
Figure 6–3
the associated OCT calibration circuitry.
Figure 6–3. Cyclone IV Devices R
RUP and RDN pins go to a tri-state condition when calibration is completed or not
running. These two pins are dual-purpose I/Os and function as regular I/Os if you
do not use the calibration circuit.

On-Chip Series Termination Without Calibration

Cyclone IV devices support driver impedance matching to match the impedance of
the transmission line, which is typically 25 or 50 . When used with the output
drivers, OCT sets the output driver impedance to 25 or 50 . Cyclone IV devices also
support I/O driver series termination (R
Cyclone IV Device Handbook,
Volume 1
shows the external calibration resistors setup on the RUP and RDN pins and
OCT with Calibration Setup
S
Cyclone IV Device Family OCT with
Calibration with RUP and RDN pins
OCT
Calibration
Circuitry
Chapter 6: I/O Features in Cyclone IV Devices
V
CCIO
External
Calibration
Resistor
RUP
V
CCIO
RDN
External
Calibration
Resistor
GND
= 50 ) for SSTL-2 and SSTL-18.
S
March 2016 Altera Corporation
OCT Support