Ucf location constraints, Discrete leds, Locations and labels – Xilinx MIcroblaze Development Spartan-3E 1600E User Manual

Page 19: Figure 2-9, Figure 2-8

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MicroBlaze Development Kit Spartan-3E 1600 Edition User Guide

17

UG257 (v1.1) December 5, 2007

www.xilinx.com

Discrete LEDs

R

UCF Location Constraints

Figure 2-9

provides the UCF constraints for the four push-button switches, including the

I/O pin assignment and the I/O standard used, and defines a pull-down resistor on each

input.

Discrete LEDs

Locations and Labels

The MicroBlaze Development Kit board has eight individual surface-mount LEDs located

above the slide switches as shown in

Figure 2-10

. The LEDs are labeled LED7 through

LED0. LED7 is the left-most LED, LED0 the right-most LED.

Figure 2-8:

Outputs from Rotary Shaft Encoder May Include Mechanical Chatter

A

B

Detent

Detent

UG257_02_08_060206

Rotating RIGHT

Switch closing chatter on ‘B’
injects false “clicks” to the LEFT
(’B’ rising edge when ‘A’ is Low)

Switch opening chatter on ‘A’
injects false “clicks” to the RIGHT

Rising edge on ‘A’
when ‘B’ is Low indicates
RIGHT (clockwise) rotation

Figure 2-9:

UCF Constraints for Rotary Push-Button Switch

NET "ROT_A" LOC = "K18" | IOSTANDARD = LVTTL | PULLUP ;
NET "ROT_B" LOC = "G18" | IOSTANDARD = LVTTL | PULLUP ;
NET "ROT_CENTER" LOC = "V16" | IOSTANDARD = LVTTL | PULLDOWN ;

UG257_03_060206

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