Altera Cyclone IV - On-Chip Series Termination with Calibration

6–8 Chapter 6: I/O Features in Cyclone IV Devices
OCT Support
Cyclone IV Device Handbook, March 2016 Altera Corporation
Volume 1
1 For more details about the differential I/O standards supported in Cyclone IV I/O
banks, refer to “High-Speed I/O Interface” on page 6–24.
On-Chip Series Termination with Calibration
Cyclone IV devices support R
S
OCT with calibration in the top, bottom, and right I/O
banks. The R
S
OCT calibration circuit compares the total impedance of the I/O buffer
to the external 25- ±1% or 50- ±1% resistors connected to the
RUP and RDN pins, and
dynamically adjusts the I/O buffer impedance until they match (as shown in
Figure 6–2).
BLVDS 8,12,16 8,12,16 — — — —
1,2,3,4,
5,6,7,8
3,4,5,6,
7,8
0,1,2 —
LVDS
(3)
— — ————
5,6
——
PPDS
(3), (4)
— — ———— ——
RSDS and mini-
LVDS
(3), (4)
— — ———— ——
Differential LVPECL
(5)
— — ————
3,4,5,6,
7,8
——
Notes to Table 6–2:
(1) The default current strength setting in the Quartus II software is 50- OCT without calibration for all non-voltage reference and HSTL/SSTL Class I I/O standards.
The default setting is 25- OCT without calibration for HSTL/SSTL Class II I/O standards.
(2) The differential SSTL-18 and SSTL-2, differential HSTL-18, HSTL-15, and HSTL-12 I/O standards are supported only on clock input pins and PLL output clock pins.
(3) True differential (PPDS, LVDS, mini-LVDS, and RSDS I/O standards) outputs are supported in row I/O banks 1, 2, 5, and 6 only for Cyclone IV E devices and right
I/O banks 5 and 6 only for Cyclone IV GX devices. Differential outputs in column I/O banks require an external resistor network.
(4) This I/O standard is supported for outputs only.
(5) This I/O standard is supported for clock inputs only
(6) The default Quartus II slew rate setting is in bold; 2 for all I/O standards that supports slew rate option.
(7) Differential SSTL-18, differential HSTL-18, HSTL-15, and HSTL-12 I/O standards do not support Class II output.
(8) Cyclone IV GX devices only support right I/O pins.
(9) Altera not only offers current strength that meets the industrial standard specification but also other additional current strengths.
Table 6–2. Cyclone IV Device I/O Features Support (Part 2 of 2)
I/O Standard
IOH/IOL Current Strength
Setting (mA)
(1)
,
(9)
R
S
OCT with
Calibration
Setting, Ohm ()
R
S
OCT Without
Calibration
Setting, Ohm ()
Cyclone
IV E I/O
Banks
Support
Cyclone
IV GX I/O
Banks
Support
Slew
Rate
Option
(6)
PCI-
clamp
Diode
Support
Column I/O Row I/O
Column
I/O
Row
I/O
(8)
Column
I/O
Row
I/O
(8)