Programmable Current Drive Strength
The Cyclone II device I/O standards support various output current
Programmable
Current Drive
Strength
drive settings as shown in Table 10–6. These programmable drive-
strength settings are a valuable tool in helping decrease the effects of
simultaneously switching outputs (SSO) in conjunction with reducing
system noise. The supported settings ensure that the device driver meets
the specifications for IOH and IOL of the corresponding I/O standard.
Table 10–6. Programmable Drive Strength (Part 1 of 2)
IOH/IOL Current Strength Setting (mA)
I/O Standard
Top and Bottom I/O Pins Side I/O Pins
LVTTL (3.3 V)
4
8
4
8
12
16
20
24
4
12
16
20
24
4
LVCMOS (3.3 V)
8
8
12
16
20
24
4
12
—
—
—
4
LVTTL and LVCMOS (2.5 V)
LVTTL and LVCMOS (1.8 V)
8
8
12
16
2
—
—
2
4
4
6
6
8
8
10
12
2
10
12
2
LVCMOS (1.5 V)
4
4
6
6
8
—
10–24
Altera Corporation
February 2008
Cyclone II Device Handbook, Volume 1
ALTERA [ ALTERA CORPORATION ]
