Slide switch and Push Button interfacing with Spartan3a FPGA Project Kit
slide switch and Push Button interfacing with Spartan3a FPGA Project Kit
Slide switch
Slide switches are most common used in electronic circuits for digital input of ON/OFF states. They allow control over current flow in a circuit. You’ll usually find slide switches in SPDT or DPDT configurations.
Push Buttons
Push-button switches are the classic momentary switch. Typically these switches have a really nice, tactile feedback when you press them.
Schematic to interface Slide Switch and Push Button with Spartan3a FPGA Project Kit
Slide Switch and Push Button Placement in Spartan3a FPGA Project Kit
Interfacing Slide Switch and Push Button with Spartan3a FPGA Project Kit
Push Button interface is straight forward. One end of Push Button connected to FPGA and another end connected to ground. Slide switch interface to FPGA is Pulled High by default at open end and another end is connected to ground which act as OFF State.
VHDL Code for Slide Switch Interfacing with spartan3a FPGA Project Kit
library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.STD_LOGIC_ARITH.ALL;
use IEEE.STD_LOGIC_UNSIGNED.ALL;
entity pb_led is
Port ( pb : in STD_LOGIC_VECTOR (1 downto 0);
led : out STD_LOGIC_VECTOR (3 downto 0));
end pb_led;
architecture Behavioral of pb_led is
begin
process(pb)
begin
if pb = "01" then
led <= "01010101";
elsif pb = "10" then
led <= "10101010";
elsif pb = "11" then
led <= "11111111";
else
led <= "00000000";
end if;
end process;
User Constraint File
NET "led[3]" LOC = P49; NET "led[2]" LOC = P48; NET "led[1]" LOC = P44; NET "led[0]" LOC = P43; NET "pb[1]" LOC = P43 | Pulldown; NET "pb[0]" LOC = P44 | Pulldown;
library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.STD_LOGIC_ARITH.ALL;
use IEEE.STD_LOGIC_UNSIGNED.ALL;
entity pb_led is
Port ( pb : in STD_LOGIC_VECTOR (1 downto 0);
led : out STD_LOGIC_VECTOR (3 downto 0));
end pb_led;
architecture Behavioral of pb_led is
begin
process(pb)
begin
if pb = "01" then
led <= "01010101";
elsif pb = "10" then
led <= "10101010";
elsif pb = "11" then
led <= "11111111";
else
led <= "00000000";
end if;
end process;
end Behavioral;
User Constraint File
NET "led[3]" LOC = P49; NET "led[2]" LOC = P48; NET "led[1]" LOC = P44; NET "led[0]" LOC = P43; NET "pb[1]" LOC = P43 | Pulldown; NET "pb[0]" LOC = P44 | Pulldown;
