6–10
Chapter 6: I/O Features in Cyclone IV Devices
OCT Support
March 2016
Altera Corporation
shows the external calibration resistors setup on the
RUP
and
RDN
pins and
the associated OCT calibration circuitry.
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
S
= 50
) for SSTL-2 and SSTL-18.
Figure 6–3. Cyclone IV Devices R
S
OCT with Calibration Setup
Cyclone IV Device Family OCT with
Calibration with RUP and RDN pins
OCT
Calibration
Circ
u
itry
V
CCIO
V
CCIO
RUP
RDN
External
Calibration
Resistor
External
Calibration
Resistor
GND
Summary of Contents for Cyclone IV
Page 10: ...x Chapter Revision Dates Cyclone IV Device Handbook March 2016 Altera Corporation Volume 1...
Page 14: ...I 2 Section I Device Core Cyclone IV Device Handbook March 2016 Altera Corporation Volume 1...
Page 274: ...vi Contents Cyclone IV Device Handbook February 2015 Altera Corporation Volume 2...
Page 440: ...iv Contents Cyclone IV Device Handbook December 2016 Altera Corporation Volume 3...
Page 442: ...vi Chapter Revision Dates Cyclone IV Device Handbook December 2016 Altera Corporation Volume 3...
Page 446: ......