-------------------------------------------------------------------------
-- 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"3c011234", --	[0x00400000]	lui $1, 4660       
		X"34225678", --	[0x00400004]	ori $2, $1, 22136
		X"3c012345", --	[0x00400008]	lui $1, 9029       
		X"34236789", --	[0x0040000c]	ori $3, $1, 26505
		X"3c018765", --	[0x00400010]	lui $1, -30875     
		X"34244321", --	[0x00400014]	ori $4, $1, 17185
		X"3c019876", --	[0x00400018]	lui $1, -26506     
		X"34255432", --	[0x0040001c]	ori $5, $1, 21554
		X"00000000", --	[0x00400020]	nop                
		X"00427823", --	[0x00400024]	subu $15, $2, $2   
		X"00437823", --	[0x00400028]	subu $15, $2, $3   
		X"00447823", --	[0x0040002c]	subu $15, $2, $4   
		X"00457823", --	[0x00400030]	subu $15, $2, $5   
		X"00627823", --	[0x00400034]	subu $15, $3, $2   
		X"00637823", --	[0x00400038]	subu $15, $3, $3   
		X"00647823", --	[0x0040003c]	subu $15, $3, $4   
		X"00657823", --	[0x00400040]	subu $15, $3, $5   
		X"00827823", --	[0x00400044]	subu $15, $4, $2   
		X"00837823", --	[0x00400048]	subu $15, $4, $3   
		X"00847823", --	[0x0040004c]	subu $15, $4, $4   
		X"00857823", --	[0x00400050]	subu $15, $4, $5   
		X"00a27823", --	[0x00400054]	subu $15, $5, $2   
		X"00a37823", --	[0x00400058]	subu $15, $5, $3   
		X"00a47823", --	[0x0040005c]	subu $15, $5, $4   
		X"00a57823", --	[0x00400060]	subu $15, $5, $5   
		X"00000000", --	[0x00400064]	nop                
		X"00427822", --	[0x00400068]	sub $15, $2, $2    
		X"00437822", --	[0x0040006c]	sub $15, $2, $3    
		X"00447822", --	[0x00400070]	sub $15, $2, $4    
		X"00457822", --	[0x00400074]	sub $15, $2, $5    
		X"00627822", --	[0x00400078]	sub $15, $3, $2    
		X"00637822", --	[0x0040007c]	sub $15, $3, $3    
		X"00647822", --	[0x00400080]	sub $15, $3, $4    
		X"00657822", --	[0x00400084]	sub $15, $3, $5    
		X"00827822", --	[0x00400088]	sub $15, $4, $2    
		X"00837822", --	[0x0040008c]	sub $15, $4, $3    
		X"00847822", --	[0x00400090]	sub $15, $4, $4    
		X"00857822", --	[0x00400094]	sub $15, $4, $5    
		X"00a27822", --	[0x00400098]	sub $15, $5, $2    
		X"00a37822", --	[0x0040009c]	sub $15, $5, $3    
		X"00a47822", --	[0x004000a0]	sub $15, $5, $4    
		X"00a57822", --	[0x004000a4]	sub $15, $5, $5    
		X"00000000", --	[0x004000a8]	nop                
		X"08104000", --	[0x004000ac]	j 0x00410000 [main]
		X"00000000", --	[0x004000b0]	nop                
		X"00000000", --	[0x004000b4]
		X"00000000", --	[0x004000b8]
		X"00000000", --	[0x004000bc]
		X"00000000", --	[0x004000c0]
		X"00000000", --	[0x004000c4]
		X"00000000", --	[0x004000c8]
		X"00000000", --	[0x004000cc]
		X"00000000", --	[0x004000d0]
		X"00000000", --	[0x004000d4]
		X"00000000", --	[0x004000d8]
		X"00000000", --	[0x004000dc]
		X"00000000", --	[0x004000e0]
		X"00000000", --	[0x004000e4]
		X"00000000", --	[0x004000e8]
		X"00000000", --	[0x004000ec]
		X"00000000", --	[0x004000f0]
		X"00000000", --	[0x004000f4]
		X"00000000", --	[0x004000f8]
		X"00000000"  --	[0x004000fc]
	);

begin

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

end itest;