Initial import

git-svn-id: http://moon:8086/svn/vhdl/trunk@12 cc03376c-175c-47c8-b038-4cd826a8556b

lib/misc/hpi_port.vhd

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+-----------------------------------------------------------------------
+-- $Header: /tmp/cvsroot/VHDL/lib/misc/hpi_port.vhd,v 1.1 2008-09-04 17:48:15 Jens Exp $
+-----------------------------------------------------------------------
+library IEEE;
+use IEEE.STD_LOGIC_1164.ALL;
+use IEEE.NUMERIC_STD.ALL;
+
+	------------------------------------------------------------------
+entity hpi_port is
+	Port (
+			rst			: in std_logic;
+			clk			: in std_logic;
+			we			: in std_logic;
+			din			: in unsigned(31 downto 0);
+			dout		: out unsigned(31 downto 0);
+			hpi_d		: inout unsigned(15 downto 0);
+			hpi_a		: out unsigned(1 downto 0);
+			hpi_csn		: out std_logic;
+			hpi_wrn		: out std_logic;
+			hpi_rdn		: out std_logic
+		);
+	end hpi_port;
+
+architecture Behavioral of hpi_port is
+
+	type hpi_t is record
+		d		: unsigned(15 downto 0);
+		a		: unsigned(1 downto 0);
+		cs		: std_logic;
+		wr		: std_logic;
+		rd		: std_logic;
+		drive_d	: std_logic;
+	end record;
+	
+	------------------------------------------------------------------
+	begin
+
+	proc_lcd_port:
+	process(rst, clk)
+	variable vhpi : hpi_t;
+	begin
+		if (rst = '1') then
+			dout			<= (others => '0');
+			vhpi.d			:= (others => '0');
+			vhpi.a			:= (others => '0');
+			vhpi.cs			:= '0';
+			vhpi.wr			:= '0';
+			vhpi.rd			:= '0';
+			vhpi.drive_d	:= '0';
+		elsif rising_edge(clk) then
+			dout <= X"0000" & hpi_d;
+			if we = '1' then
+				vhpi.d			:= din(15 downto 0);
+				vhpi.a			:= din(17 downto 16);
+				vhpi.cs			:= din(18);
+				vhpi.wr			:= din(19);
+				vhpi.rd			:= din(20);
+				vhpi.drive_d	:= din(21);
+			end if;
+		end if;	
+		if vhpi.cs = '1' then	
+			hpi_a	 <= vhpi.a;
+		else
+			hpi_a	 <= (others => 'Z');
+		end if;
+		if vhpi.drive_d = '1' and vhpi.rd = '0' then	
+			hpi_d	 <= vhpi.d;
+		else
+			hpi_d	 <= (others => 'Z');
+		end if;
+		hpi_csn	<= not vhpi.cs;
+		hpi_wrn	<= not vhpi.wr;
+		hpi_rdn	<= not vhpi.rd;
+	end process;
+	------------------------------------------------------------------
+
+end Behavioral;