I/O Structure & Features
Table 2–16. Programmable Drive Strength (Part 2 of 2)
Note (1)
I
OH/IOL Current Strength Setting (mA)
I/O Standard
Top & Bottom I/O Pins
Side I/O Pins
LVCMOS (1.5 V)
2
2
4
6
4
6
8
SSTL-2 class I
SSTL-2 class II
8
8
12
16
20
24
6
12
16
SSTL-18 class I
6
8
8
10
12
16
18
8
10
SSTL-18 class II
HSTL-18 class I
8
10
12
16
18
20
8
10
12
HSTL-18 class II
HSTL-15 class I
8
10
12
16
HSTL-15 class II
Note to Table 2–16:
(1) The default current in the Quartus II software is the maximum setting for each
I/O standard.
Open-Drain Output
Cyclone II devices provide an optional open-drain (equivalent to an
open-collector) output for each I/O pin. This open-drain output enables
the device to provide system-level control signals (that is, interrupt and
write-enable signals) that can be asserted by any of several devices.
2–50
Cyclone II Device Handbook, Volume 1
Altera Corporation
February 2007
ALTERA [ ALTERA CORPORATION ]
