EP3C16F256I7N Altera, EP3C16F256I7N Datasheet - Page 110

• Manufacturer Part Number: EP3C16F256I7N
• Description: Cyclone III
• Manufacturer: Altera

6–10
On-Chip Series Termination Without Calibration
Cyclone III Device Handbook, Volume 1
Figure 6–4
the associated OCT calibration circuitry.
Figure 6–4. Cyclone III Device Family On-Chip Series Termination with Calibration Setup
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.
The Cyclone III device family supports driver impedance matching to the impedance
of the transmission line, which is typically 25 Ω or 50 Ω. When used with the output
drivers, OCT sets the output driver impedance to 25 Ω or 50 Ω. The Cyclone III device
family also supports I/O driver series termination (R
SSTL-18.
shows the external calibration resistors setup on the RUP and RDN pins and
Cyclone III Device Family OCT with
Calibration with RUP and RDN pins
Calibration
Circuitry
OCT
V
CCIO
Chapter 6: I/O Features in the Cyclone III Device Family
RUP
RDN
S
= 50 Ω) for SSTL-2 and
V
GND
CCIO
© December 2009 Altera Corporation
External
Calibration
Resistor
External
Calibration
Resistor
OCT Support