-----------------------------------------------------------------------------                                                                     
 -- Project Name         : NCO                                            
 --                                                                             
 -- Author               : Bluetea
 -- Creation Date        : 03/11/04 18:20:21                                              
 -- Version Number       : 1.0                                                                                                                                                                                             
 -- Description          :                                                                                                                                  
 -- This ,module is the 1/4 wave sin lookup table.  The input to the block is
 -- the phase angle value and the output is the 8 bit sin value.
 -----------------------------------------------------------------------------

LIBRARY ieee;
USE ieee.std_logic_1164.all;
USE ieee.std_logic_arith.all;
LIBRARY lpm;
USE lpm.lpm_components.all;

ENTITY romtab IS
       PORT(
             SYSCLK    : IN  STD_LOGIC;
             PHASEADD  : IN  STD_LOGIC_VECTOR (5 DOWNTO 0);--phase address value
             QWAVESIN  : OUT STD_LOGIC_VECTOR (6 DOWNTO 0) --1/4 wave sin value
            );
END romtab;

ARCHITECTURE ROM OF romtab IS

    SIGNAL sub_wire0	: STD_LOGIC_VECTOR (6 DOWNTO 0);

	COMPONENT LPM_ROM                      --sine wave ROM
	GENERIC (
		LPM_WIDTH		     : POSITIVE;
		LPM_WIDTHAD		     : POSITIVE;
		LPM_ADDRESS_CONTROL  : STRING;
		LPM_INDATA		     : STRING;
		LPM_OUTDATA		     : STRING;
		LPM_FILE		     : STRING
	);
	PORT (
			address	: IN STD_LOGIC_VECTOR (5 DOWNTO 0);
			inclock	: IN STD_LOGIC ;
			q	: OUT STD_LOGIC_VECTOR (6 DOWNTO 0)
	);
	END COMPONENT;
	
BEGIN	
	QWAVESIN <= sub_wire0(6 DOWNTO 0);

	LPM_ROM_component : LPM_ROM
	GENERIC MAP (
		LPM_WIDTH => 7,
		LPM_WIDTHAD => 6,
		LPM_ADDRESS_CONTROL => "REGISTERED",
		LPM_INDATA => "REGISTERED",
		LPM_OUTDATA => "UNREGISTERED",
		LPM_FILE => "f:\dds2\dds\ncosin.mif"
	)
	PORT MAP (
		address => PHASEADD,
		inclock => SYSCLK,
        q => sub_wire0
	);	
END ROM;