Figure 2-14 – Digilent 6003-410-000P-KIT User Manual
Page 44
44
XUP Virtex-II Pro Development System
UG069 (v1.0) March 8, 2005
Chapter 2: Using the System
R
Using the Expansion Headers and Digilent Expansion Connectors
The XUP Virtex-II Pro Development System allows for four user-supplied expansion
headers that are tailored to accept ribbon cables, and two front mounted connectors that
are designed to accept Digilent peripheral devices and a single Digilent high-speed port. A
total of 80 low-speed signals are provided, with most of the signals shared between the
headers (J1-4) and the front-mounted connectors (J5-6). All of these signals are equipped
with over-voltage protection devices (J34-41) to protect the Virtex-II Pro FPGA. The IDT™
QuickSwitch devices (IDTQS32861) provide protection from signal sources up to 7V.
through
provide the FPGA connection information and outline the
signals that are shared between the two expansion connector types.
Various power supply voltages are available on the expansion connectors, 2.5V, 3.3V, and
5.0V, depending on the connector type. The expansion headers are positioned to prevent
the installation of a ribbon cable connector across two of the expansion headers. Every
second signal in the ribbon cable is a ground signal to provide the best signal integrity at
the user’s target. The output of the over-voltage protection device follows the input
voltage up to a diode drop below the V
CC
rail; at which time, the voltage is clamped. So
with a V
CC
of 3.3V, the output clamps at -2.5V. This gives 500 mV of input switching
margin for both LVTTL and LVCMOS3.3, which have a V
IH
of 2.0V minimum.
The expansion headers (J1-J4) are user installed items. These headers can be purchased
from Digikey under the part number S2012-30-ND.
identifies the location of
the expansion headers.
PB_LEFT
I
AH1
LVTTL
–
–
PB_RIGHT
I
AH2
LVTTL
–
–
Table 2-9:
User LED and Switch Connections (Continued)
Signal
Direction
FPGA Pin
I/O Type
Drive
Slew
Figure 2-14:
Expansion Headers