Altera Nios Development Board - Manual (Page 23)

Altera Corporation 2–15
July 2005 Nios Development Board Reference Manual, Stratix II Edition
Board Components
Figure 2–5. Serial Connector J19
Figure 2–6. Serial Connector J27
Expansion
Prototype
Connectors
(PROTO1 &
PROTO2) PROTO1 and PROTO2 are standard-footprint, mechanically-stable
connections that can be used (for example) as an interface to a special-
function daughter card. Headers J11, J12, and J13
collectively form
PROTO1, and J15, J16 and J17 collectively form PROTO2.
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 Stratix II device. Each signal passes through analog switches
to protect the Stratix II device from 5V logic levels. These analog
switches are permanently enabled. The output logic-level on the
expansion prototype connector pins is 3.3V.
● PROTO1 switches: U19, U20, U21, U22 and U25
● PROTO2 switches: U27, U28, U29, U30 and U31
■ A buffered, zero-skew copy of the on-board oscillator output from
U2.
■ A buffered, zero-skew copy of the Stratix II phase-locked loop (PLL)
output from U60.