Digilent Digilab 2 - Manual (Page 9)

Digilent Digilab 2 Reference Manual Digilent, Inc.
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Pushbutton and LED
A single pushbutton and LED are provided on the board, allowing basic status and control functions to
be implemented without a peripheral board. For example, the LED can be illuminated from a signal in
the FPGA to verify that configuration has been successful, and the pushbutton can be used to provide a
basic reset function independent of other inputs. The circuits are shown in Figure 5, below.
Xilinx
Spartan 2
PQ208
P77
P71
Vdd
4.7K
4.7K
Push
button
80 Ohm
Figure 5. Pushbutton and LED detail
Spartan 2 FPGA
The block diagram of the Digilab 2
board (Page 1) shows all
connections between the FPGA and
the devices on the board. All FPGA
pin connections are shown in Table
3 (below).
The Spartan device, shown in Figure
6, can be configured using the Xilinx
JTAG tools and a parallel cable
connecting the D2 board and the
host computer. Note that a separate
JTAG header that connects directly
to the JTAG pins is also provided.
For further information on the
Spartan FPGA, please see the Xilinx
data sheets available at the Xilinx
website (www.xilinx.com).
Expansion E
DB-25 parallel port DB-9 serial port
LED
Push
button
Clock
SPROM
JTAG
Expansion A
Expansion F
Expansion B Expansion C
Expansion D
37 37
37
9
5 4
13
4
Spartan 2 PQ208
Figure 6. Spartan 2 connection detail