Switches, buttons, and knob, Slide switches, Locations and labels – Xilinx MIcroblaze Development Spartan-3E 1600E User Manual
Page 15: Operation, Ucf location constraints, Chapter 2: switches, buttons, and knob, Chapter 2, “switches, buttons, and knob, Chapter 2

MicroBlaze Development Kit Spartan-3E 1600 Edition User Guide
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UG257 (v1.1) December 5, 2007
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Chapter 2
Switches, Buttons, and Knob
Slide Switches
Locations and Labels
The MicroBlaze Development Kit board has four slide switches, as shown in
The slide switches are located in the lower right corner of the board and are labeled SW3
through SW0. Switch SW3 is the left-most switch, and SW0 is the right-most switch.
Operation
When in the UP or ON position, a switch connects the FPGA pin to 3.3V, a logic High.
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.
UCF Location Constraints
provides the UCF constraints for the four slide switches, including the I/O pin
assignment and the I/O standard used. The PULLUP resistor is not required, but it defines
the input value when the switch is in the middle of a transition.
Figure 2-1:
Four Slide Switches
Spartan-3E
Development Board
HIGH
LOW
UG257_02_01_061306
S
W0
S
W
3