LIBRARY IEEE;
USE IEEE.std_logic_1164.ALL;
USE IEEE.numeric_std.ALL;
ENTITY gpio IS
 PORT (clk, reset : IN std_logic;
		 bit21 		: INOUT std_logic);
END ENTITY gpio;
ARCHITECTURE bhv OF gpio IS
BEGIN

PROCESS(clk,reset)
	VARIABLE shouldWrite	:	INTEGER;
	BEGIN
	shouldWrite := 1;

	-- MAIN LOOP
	IF falling_edge(clk) THEN
		IF bit21 = '0' THEN --Signal bit is off, no signal on all pins
			IF shouldWrite = 1 THEN --If the FPGA should be writing, go write
			-- WRITE LOOP (write to the io pins the value that needs to be send)



			-- END WRITE LOOP (note that the pins should be off when leaving this loop.
			shouldWrite := 0; -- We have written this loop, preventing next loop from writing
			END IF;
		ELSE --Signal is on, so pi is sending something
			IF shouldWrite = 0 THEN--shouldWrite = 0 means we have to read
			--READ LOOP (read the pins and store in the variables)
				--Note, when making a read loop, check if the last an current read are the same. If so, ignore the output



			--END READ LOOP
			shouldWrite := 1; -- we have read, so we need to write again
			END IF;
		END IF;
		 -- CALCULATE LOOP (calculate using the variables), this loop cannot take too long, so dont have one big calc, but seperate it



		 -- END CALCULATE LOOP

	END IF;
END PROCESS;

END;