library IEEE;
use IEEE.std_logic_1164.all;
use IEEE.numeric_std.all;

--use work.math_pkg.all;
use work.common_pkg.all;
use work.core_pkg.all;

use work.mem_pkg.all;
use work.extension_pkg.all;
use work.extension_7seg_pkg.all;

architecture behav of extension_7seg is

signal s_state, s_state_nxt : sseg_state_rec;
signal ext_reg_r  : extmod_rec;

begin

seg_syn: process(sys_clk, sys_res_n)

begin

	if (sys_res_n = RESET_VALUE) then
		
		s_state.digit0 <= (others => '0');--set(0,7);
		s_state.digit1 <= (others => '0');--set(0,7);
		s_state.digit2 <= (others => '0');--set(0,7);
		s_state.digit3 <= (others => '0');--set(0,7);

		ext_reg_r.sel <='0';
		ext_reg_r.wr_en <= '0';
		ext_reg_r.byte_en <= (others => '0');
		ext_reg_r.data <= (others => '0');
		ext_reg_r.addr <= (others => '0');
		
	elsif rising_edge(sys_clk) then
		
		s_state <= s_state_nxt;
		ext_reg_r <= ext_reg;
		
	end if;
	
end process; 

seg_asyn: process(s_state, ext_reg_r)	

variable tmp_data  : byte_t;

begin
	s_state_nxt <= s_state;	
	tmp_data := (others =>'0');			

	if ext_reg_r.sel = '1' and ext_reg_r.wr_en = '1' then

		tmp_data(byte_t'range) :=ext_reg_r.data(byte_t'range);

		s_state_nxt.digit0 <= digit_decode('0' & ext_reg_r.data(3 downto 0));
		s_state_nxt.digit1 <= digit_decode('0' & ext_reg_r.data(7 downto 4));
		s_state_nxt.digit2 <= digit_decode('0' & ext_reg_r.data(11 downto 8));
		s_state_nxt.digit3 <= digit_decode('0' & ext_reg_r.data(15 downto 12));

		case ext_reg_r.byte_en(1 downto 0) is
		when "01" => s_state_nxt.digit3 <= digit_decode("11111");
		when "00" => null;
		when "10" => null;
		when "11" => null;
		when others => null;
		end case;


	end if;

end process; --ps2_next

seg_out: process(s_state)
begin
	
	o_digit0 <= not(s_state.digit0);
	o_digit1 <= not(s_state.digit1);
	o_digit2 <= not(s_state.digit2);
	o_digit3 <= not(s_state.digit3);

end process;

end behav;