EP2C20F256C8N Datasheet, PDF (306/470 Pages) Altera Corporation – Cyclone II Device Handbook, Volume 1

Programmable Current Drive Strength
Programmable
Current Drive
Strength
The Cyclone II device I/O standards support various output current
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 I_OH and I_OL of the corresponding I/O standard.
Table 10–6. Programmable Drive Strength (Part 1 of 2)
I/O Standard
LVTTL (3.3 V)
LVCMOS (3.3 V)
LVTTL and LVCMOS (2.5 V)
LVTTL and LVCMOS (1.8 V)
LVCMOS (1.5 V)
I_OH/I_OL Current Strength Setting (mA)
Top and Bottom I/O Pins Side I/O Pins
4
4
8
8
12
12
16
16
20
20
24
24
4
4
8
8
12
12
16
—
20
—
24
—
4
4
8
8
12
—
16
—
2
2
4
4
6
6
8
8
10
10
12
12
2
2
4
4
6
6
8
—
10–24
Cyclone II Device Handbook, Volume 1
Altera Corporation
February 2008