HW-SPAR3E-SK-US-G Xilinx Inc, HW-SPAR3E-SK-US-G Datasheet - Page 17

• Manufacturer Part Number: HW-SPAR3E-SK-US-G
• Description: KIT STARTER SPARTAN-3E
• Manufacturer: Xilinx Inc

Specifications of HW-SPAR3E-SK-US-G

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 122-1507

Rotary Push-Button Switch
Spartan-3E FPGA Starter Kit Board User Guide
UG230 (v1.2) January 20, 2011
UCF Location Constraints
Locations and Labels
Operation
R
Push-Button Switch
In some applications, the BTN_SOUTH push-button switch is also a soft reset that
selectively resets functions within the FPGA.
Figure 2-5
I/O pin assignment and the I/O standard used, and defines a pull-down resistor on each
input.
The rotary push-button switch is located in the center of the four individual push-button
switches, as shown in
encoder outputs are ROT_A and ROT_B. The center push-button switch is ROT_CENTER.
The rotary push-button switch integrates two different functions. The switch shaft rotates
and outputs values whenever the shaft turns. The shaft can also be pressed, acting as a
push-button switch.
Pressing the knob on the rotary/push-button switch connects the associated FPGA pin to
3.3V, as shown in
generate a logic Low.
There is no active debouncing circuitry on the push button.
Figure 2-4: Push-Button Switches Require an Internal Pull-Down Resistor in FPGA
NET
NET
NET
NET
"BTN_EAST"
"BTN_NORTH"
"BTN_SOUTH"
"BTN_WEST"
provides the UCF constraints for the four push-button switches, including the
3.3V
Figure 2-5: UCF Constraints for Push-Button Switches
Figure
Figure 2-9
Push Button
Figure
LOC
LOC
LOC
LOC
2-6. Use an internal pull-down resistor within the FPGA pin to
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= "H13" |
= "V4"
= "K17" |
= "D18" |
2-3. The switch produces three outputs. The two shaft
shows how to specify a pull-down resistor within the UCF.
|
Input Pin
FPGA I/O Pin
IOSTANDARD
IOSTANDARD
IOSTANDARD
IOSTANDARD
= LVTTL |
= LVTTL |
= LVTTL |
= LVTTL |
Rotary Push-Button Switch
BTN_* Signal
UG230_c2_03_021206
PULLDOWN
PULLDOWN
PULLDOWN
PULLDOWN
;
;
;
;
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