Altera Nios Development Board - Manual (Page 20)

1–12 Altera Corporation
Nios Development Board Reference Manual, Cyclone Edition December 2004
Expansion Prototype Connector (PROTO1)
The expansion prototype connector interface includes:
■ 41 I/O pins for prototyping. All 41 I/O pins connect to user I/O pins
on the Cyclone device. Each signal passes through analog switches
(U19, U20, U21, U22 and U25) to protect the Cyclone device from 5-
V logic levels. These analog switches are permanently enabled.
■ A buffered, zero-skew copy of the on-board OSC output from U2.
■ A buffered, zero-skew copy of the Cyclone's phase-locked loop
(PLL)-output from U60.
■ A logic-negative power-on reset signal
■ Five regulated 3.3-V power-supply pins (2A total max load for both
PROTO1 & PROTO2)
■ One regulated 5-V power-supply pin (1A total max load for both
PROTO1 & PROTO2)
■ Numerous ground connections
The output logic-level on the expansion prototype connector pins is 3.3V.
The power supply included wit the Nios II development kit cannot
supply the maximum load current specified above.
Figure 1–5 , Figure 1–6 , and Figure 1–7 show connections from the
PROTO1 expansion headers to the Cyclone device. Unless otherwise
noted, labels indicate Cyclone device pin numbers.
Figure 1–5. Expansion Prototype Connector - J11