-------------------------------------------------------------------------
-- Project: JCPU, a portable 8-bit RISC CPU written in VHDL
-- This file: The ROM file for use in your VHDL design
--
-- Copyright (C) 2007 J. Ahrensfeld
--
-- This program is free software: you can redistribute it and/or modify
-- it under the terms of the GNU General Public License as published by
-- the Free Software Foundation, either version 3 of the License, or
-- (at your option) any later version.
--
-- This program is distributed in the hope that it will be useful,
-- but WITHOUT ANY WARRANTY; without even the implied warranty of
-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-- GNU General Public License for more details.
--
-- You should have received a copy of the GNU General Public License
-- along with this program.  If not, see <http://www.gnu.org/licenses/>.
--
-- For questions and ideas, please contact the author at jens@jayfield.org
--
--------------------------------------------------------------------------

LIBRARY ieee;
use IEEE.STD_LOGIC_1164.ALL;
USE ieee.numeric_std.ALL;


ENTITY rom IS
	Generic 
	(
		addr_width 	: integer := 2;
		data_width 	: integer := 32
	);
	Port 
	(
		addr		: in  unsigned(addr_width-1 downto 0);
		dout		: out unsigned(data_width-1 downto 0)
	);
END rom;

ARCHITECTURE itest OF rom IS 
	
	subtype word_t is unsigned(data_width-1 downto 0);
	type word_array_t is array (0 to 2**addr_width-1) of word_t;

	-- Assembled from itest.jsm
	constant word_array : word_array_t :=
	(
		X"08100001", --	[0x00400000]	j 0x00400004 [main]              
		X"3c011234", --	[0x00400004]	lui $1, 4660                    
		X"34215678", --	[0x00400008]	ori $1, $1, 22136                
		X"3021f00f", --	[0x0040000c]	andi $1, $1, -4081              
		X"2021affc", --	[0x00400010]	addi $1, $1, -20484              
		X"2021ffff", --	[0x00400014]	addi $1, $1, -1                 
		X"1c20fffe", --	[0x00400018]	bgtz $1 -8 [loop-0x00400018]     
		X"3c020000", --	[0x0040001c]	lui $2, 0                       
		X"34420001", --	[0x00400020]	ori $2, $2, 1                    
		X"3c010000", --	[0x00400024]	lui $1, 0                        
		X"34210004", --	[0x00400028]	ori $1, $1, 4                    
		X"00220822", --	[0x0040002c]	sub $1, $1, $2                   
		X"1c20fffe", --	[0x00400030]	bgtz $1 -8 [loop2-0x00400030]    
		X"3c1f0040", --	[0x00400034]	lui $31, 64                      
		X"03e00008", --	[0x00400038]	jr $31                           
		X"00000000", --	[0x0040003c]	nop                              
		X"00000000", --	[0x00400040]	nop
		X"00000000", --	[0x00400044]	nop   
		X"00000000", --	[0x00400048]	nop  
		X"00000000", --	[0x0040004c]	nop   
		X"00000000", --	[0x00400050]	nop   
		X"00000000", --	[0x00400054]	nop   
		X"00000000", --	[0x00400058]	nop   
		X"00000000", --	[0x0040005c]	nop  
		X"00000000", --	[0x00400060]	nop  
		X"00000000", --	[0x00400064]	nop  
		X"00000000", --	[0x00400068]	nop  
		X"00000000", --	[0x0040006c]	nop    
		X"00000000", --	[0x00400070]	nop    
		X"00000000", --	[0x00400074]	nop    
		X"00000000", --	[0x00400078]	nop    
		X"00000000", --	[0x0040007c]	nop    
		X"00000000", --	[0x00400080]	nop    
		X"00000000", --	[0x00400084]	nop    
		X"00000000", --	[0x00400088]	nop    
		X"00000000", --	[0x0040008c]	nop    
		X"00000000", --	[0x00400090]	nop    
		X"00000000", --	[0x00400094]	nop    
		X"00000000", --	[0x00400098]	nop    
		X"00000000", --	[0x0040009c]	nop    
		X"00000000", --	[0x004000a0]	nop    
		X"00000000", --	[0x004000a4]	nop    
		X"00000000", --	[0x004000a8]	nop    
		X"00000000", --	[0x004000ac]	nop
		X"00000000", --	[0x004000b0]	nop
		X"00000000", --	[0x004000b4]	nop
		X"00000000", --	[0x004000b8]	nop
		X"00000000", --	[0x004000bc]	nop
		X"00000000", --	[0x004000c0]	nop
		X"00000000", --	[0x004000c4]	nop
		X"00000000", --	[0x004000c8]	nop
		X"00000000", --	[0x004000cc]	nop
		X"00000000", --	[0x004000d0]	nop
		X"00000000", --	[0x004000d4]	nop
		X"00000000", --	[0x004000d8]	nop
		X"00000000", --	[0x004000dc]	nop
		X"00000000", --	[0x004000e0]	nop
		X"00000000", --	[0x004000e4]	nop
		X"00000000", --	[0x004000e8]	nop
		X"00000000", --	[0x004000ec]	nop
		X"00000000", --	[0x004000f0]	nop
		X"00000000", --	[0x004000f4]	nop
		X"00000000", --	[0x004000f8]	nop
		X"00000000"  --	[0x004000fc]	nop
	);

begin

PROM_READ:
	dout <= word_array(to_integer(addr));

end itest;