83 lines
2.6 KiB
VHDL
83 lines
2.6 KiB
VHDL
---------- DEFAULT LIBRARY ---------
|
|
LIBRARY IEEE;
|
|
USE IEEE.STD_LOGIC_1164.ALL;
|
|
USE IEEE.NUMERIC_STD.ALL;
|
|
------------------------------------
|
|
|
|
ENTITY KittCar IS
|
|
GENERIC (
|
|
|
|
CLK_PERIOD_NS : POSITIVE RANGE 1 TO 100 := 10; -- clk period in nanoseconds
|
|
MIN_KITT_CAR_STEP_MS : POSITIVE RANGE 1 TO 2000 := 1; -- Minimum step period in milliseconds (i.e., value in milliseconds of Delta_t)
|
|
|
|
NUM_OF_SWS : INTEGER RANGE 1 TO 16 := 16; -- Number of input switches
|
|
NUM_OF_LEDS : INTEGER RANGE 1 TO 16 := 16 -- Number of output LEDs
|
|
|
|
);
|
|
PORT (
|
|
|
|
------- Reset/Clock --------
|
|
reset : IN STD_LOGIC;
|
|
clk : IN STD_LOGIC;
|
|
----------------------------
|
|
|
|
-------- LEDs/SWs ----------
|
|
sw : IN STD_LOGIC_VECTOR(NUM_OF_SWS - 1 DOWNTO 0); -- Switches avaiable on Basys3
|
|
led : OUT STD_LOGIC_VECTOR(NUM_OF_LEDS - 1 DOWNTO 0) -- LEDs avaiable on Basys3
|
|
----------------------------
|
|
|
|
);
|
|
END KittCar;
|
|
|
|
ARCHITECTURE Behavioral OF KittCar IS
|
|
CONSTANT MIN_KITT_CAR_STEP_NS : UNSIGNED(46 DOWNTO 0) := to_unsigned(MIN_KITT_CAR_STEP_MS * 1000000, 47);
|
|
|
|
SIGNAL leds_sr : STD_LOGIC_VECTOR(led'RANGE) := (OTHERS => '0');
|
|
BEGIN
|
|
|
|
-- Sincronous logic
|
|
PROCESS (clk, reset)
|
|
VARIABLE counter : UNSIGNED(46 DOWNTO 0) := (OTHERS => '0');
|
|
VARIABLE n_period : UNSIGNED(NUM_OF_SWS DOWNTO 0) := to_unsigned(1, NUM_OF_SWS + 1);
|
|
VARIABLE up : STD_LOGIC := '1';
|
|
BEGIN
|
|
IF reset = '1' THEN
|
|
leds_sr <= (OTHERS => '0');
|
|
counter := (OTHERS => '0');
|
|
ELSIF rising_edge(clk) THEN
|
|
|
|
-- Handle the switch
|
|
n_period := unsigned('0' & sw) + 1;
|
|
|
|
-- Kitt logic
|
|
IF unsigned(leds_sr) = 0 THEN
|
|
leds_sr(0) <= '1';
|
|
up := '1';
|
|
ELSIF leds_sr(led'HIGH) = '1' THEN
|
|
up := '0';
|
|
ELSIF leds_sr(led'LOW) = '1' THEN
|
|
up := '1';
|
|
END IF;
|
|
|
|
-- Increment the counter
|
|
counter := counter + to_unsigned(CLK_PERIOD_NS, counter'LENGTH);
|
|
|
|
-- Calculate the number of periods
|
|
IF counter >= (MIN_KITT_CAR_STEP_NS * n_period) THEN
|
|
|
|
-- Shift the leds
|
|
IF up = '1' THEN
|
|
leds_sr <= leds_sr(NUM_OF_LEDS - 2 DOWNTO 0) & '0';
|
|
ELSIF up = '0' THEN
|
|
leds_sr <= '0' & leds_sr(NUM_OF_LEDS - 1 DOWNTO 1);
|
|
END IF;
|
|
|
|
-- Reset the counter
|
|
counter := (OTHERS => '0');
|
|
END IF;
|
|
END IF;
|
|
END PROCESS;
|
|
|
|
led <= leds_sr;
|
|
|
|
END Behavioral; |