copyleft: gplv3 added and set repo to public

[calu.git] / cpu / src / decoder_b.vhd

diff --git a/cpu/src/decoder_b.vhd b/cpu/src/decoder_b.vhd
index 525d408170a0b6b5bca6b12cfe42ec07f85df0e1..abeedb9806ef1e2371a876e229f4eeb6f8f66922 100644 (file)
--- a/cpu/src/decoder_b.vhd
+++ b/cpu/src/decoder_b.vhd
@@ -1,3 +1,24 @@
+--   `Deep Thought', a softcore CPU implemented on a FPGA
+--
+--  Copyright (C) 2010 Markus Hofstaetter <markus.manrow@gmx.at>
+--  Copyright (C) 2010 Martin Perner <e0725782@student.tuwien.ac.at>
+--  Copyright (C) 2010 Stefan Rebernig <stefan.rebernig@gmail.com>
+--  Copyright (C) 2010 Manfred Schwarz <e0725898@student.tuwien.ac.at>
+--  Copyright (C) 2010 Bernhard Urban <lewurm@gmail.com>
+--
+--  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/>.
+
 library IEEE;
 use IEEE.std_logic_1164.all;
 use IEEE.numeric_std.all;
@@ -312,16 +333,21 @@ begin
                instr_s.reg_dest_addr := instruction(22 downto 19);
                instr_s.op_group := STACK_OP;
                instr_s.op_detail(NO_PSW_OPT) := '1';
+               instr_s.op_detail(PWREN_OPT) := '1';
        
                case instruction(18 downto 17) is
-                       when "00" => 
+                       when "00" => --pop
                                instr_s.op_detail(PUSH_OPT) := '0';
                        
-                       when "01" => null;
+                       when "01" => --disc
+                               instr_s.op_detail(PUSH_OPT) := '0';
+                               instr_s.op_detail(NO_DST_OPT) := '1';
                        
-                       when "10" => null;
+                       when "10" => --fetch
+                               instr_s.op_detail(PUSH_OPT) := '0';
+                               instr_s.op_detail(PWREN_OPT) := '0';
                        
-                       when "11" =>
+                       when "11" => --push
                                instr_s.op_detail(PUSH_OPT) := '1';
                                
                        when others => null;