--32 bit signed multiplier
--Rachel Hadaway
--Feb 28 2003
Library LPM;
use lpm.lpm_components.all;

entity mult is
	port (mcand, mplier : in bit_vector (31 downto 0);
		clock, reset : in bit;
		product : out bit_vector (63 downto 0);
		done : out bit
		);
end entity mult;

architecture mult_arch is
component mult_fsm 
	port (mplier : in bit_vector; clock, reset : in bit; done : inout bit; start_out, add_out, shift_out, mplier_bit : out bit);
end component;

signal mplier_bit, start_out, zerosig, add_out, shift_out : bit;
signal product_reg : bit_vector (63 downto 0);
signal mcand_reg : bit_vector (31 downto 0);
begin
zerosig <= '0';
myadd : lpm_add_sub
	generic map(lpm_width => 32)
	port map (cin => 0, 
				dataa <= mcand_reg,
				datab <= product_reg,
				result <= product_reg,
				cout <= add_out);

registers: process (clock, reset)
begin
	if reset = '0' then
		product_reg = "0000000000000000000000000000000000000000000000000000000000000000";
		--64 bits of 0
		mcand_reg = mcand;
		end if;
end process;
	
while (done /= '1')
	mplier_bit = mplier(0);
 fsm1 : mult_fsm port map(mplier, clock, reset, mplier_bit, start_out, add_out, shift_out);
if (add_out = '1' and mplier_bit) then
	add1: lpm_add_sub port map (zerosig, mcand_reg, product_reg(63 downto 32), product_reg(63 downto 32), add_out);
elsif shift_out = '1' then