Chapter 4: Switches And Leds; Slide Switches; Push Button Switches - Xilinx Spartan-3 User Manual

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Switches and LEDs

Slide Switches

The Spartan-3 Starter Kit board has eight slide switches, indicated as
switches are located along the lower edge of the board, toward the right edge. The switches
are labeled SW7 through SW0. Switch SW7 is the left-most switch, and SW0 is the right-
most switch. The switches connect to an associated FPGA pin, as shown in
detailed schematic appears in
Table 4-1: Slider Switch Connections
When in the UP or ON position, a switch connects the FPGA pin to V
When DOWN or in the OFF position, the switch connects the FPGA pin to ground, a logic
Low. The switches typically exhibit about 2 ms of mechanical bounce and there is no active
debouncing circuitry, although such circuitry could easily be added to the FPGA design
programmed on the board. A 4.7KΩ series resistor provides nominal input protection.

Push Button Switches

The Spartan-3 Starter Kit board has four momentary-contact push button switches,
indicated as
board, toward the right edge. The switches are labeled BTN3 through BTN0. Push button
switch BTN3 is the left-most switch, BTN0 the right-most switch. The push button
switches connect to an associated FPGA pin, as shown in
appears in
Table 4-2: Push Button Switch Connections
Pressing a push button generates a logic High on the associated FPGA pin. Again, there is
no active debouncing circuitry on the push button.
The left-most button, BTN3, is also the default User Reset pin. BTN3 electrically behaves
identically to the other push buttons. However, when applicable, BTN3 resets the provided
reference designs.
Spartan-3 Starter Kit Board User Guide
UG130 (v1.1) May 13, 2005
SW7 SW6
Switch
FPGA Pin K13 K14
in Figure
13
Figure A-2.
Push Button BTN3 (User Reset)
FPGA Pin L14
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1-800-255-7778
Figure A-2.
SW5 SW4 SW3
J13 J14 H13
1-2. These push buttons are located along the lower edge of the
BTN2
L13
Chapter 4
in Figure 1-2. The
11
Table 4-1. A
SW2 SW1 SW0
H14 G12 F12
, a logic High.
CCO
Table 4-2. A detailed schematic
BTN1 BTN0
M14 M13
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