When using a basys 3 FPGA board and using VHDL how would you

When using a basys 3 FPGA board, and using VHDL, how would you get LED 1 then LED 2 then LED 3 then LED 2 then LED 1 to light up after turning on Switch 1?

Solution

USE a shiftregister.
LET you have 3 LEDs TO GLOW THEM ONE BY ONE then make a shiftregister of 3 bit.

signal LEDreg : std_logic_vector(2 downto 0) := (others => \'0\');

p_shiftreg : process (clk)
begin
if rising_edge(clk)then
   Ledreg(0) <= input;
   Ledreg(2 downto 1) <= Ledreg(1 downto 0);
end if;
end process p_shiftreg;

the input is a std_logic, it can be practically anything depending on how and what ou want to implement.
for example you could make a continuous binary counter and decode that input becomes one at one value. Then input will become 1 every X times and will shift trough the register.
for example:
signal count : std_logic_vector(2 downto 0) := (others => \'0\');

process(clk)
if rising_edge(clk)then
count <= count + \'1\';
end if;
end process;

input <= \'1\' when count = \"00000000\" else \'0\';

The LEDs you connect to every flip flop in the register.