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//////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////
////                                                              ////
////                                                              ////
////  OR1200's Instruction decode                                 ////
////  OR1200's Instruction decode                                 ////
////                                                              ////
////                                                              ////
////  This file is part of the OpenRISC 1200 project              ////
////  This file is part of the OpenRISC 1200 project              ////
////  http://www.opencores.org/project,or1k                       ////
////  http://www.opencores.org/project,or1k                       ////
////                                                              ////
////                                                              ////
////  Description                                                 ////
////  Description                                                 ////
////  Majority of instruction decoding is performed here.         ////
////  Majority of instruction decoding is performed here.         ////
////                                                              ////
////                                                              ////
////  To Do:                                                      ////
////  To Do:                                                      ////
////   - make it smaller and faster                               ////
////   - make it smaller and faster                               ////
////                                                              ////
////                                                              ////
////  Author(s):                                                  ////
////  Author(s):                                                  ////
////      - Damjan Lampret, lampret@opencores.org                 ////
////      - Damjan Lampret, lampret@opencores.org                 ////
////                                                              ////
////                                                              ////
//////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////
////                                                              ////
////                                                              ////
//// Copyright (C) 2000 Authors and OPENCORES.ORG                 ////
//// Copyright (C) 2000 Authors and OPENCORES.ORG                 ////
////                                                              ////
////                                                              ////
//// This source file may be used and distributed without         ////
//// This source file may be used and distributed without         ////
//// restriction provided that this copyright statement is not    ////
//// restriction provided that this copyright statement is not    ////
//// removed from the file and that any derivative work contains  ////
//// removed from the file and that any derivative work contains  ////
//// the original copyright notice and the associated disclaimer. ////
//// the original copyright notice and the associated disclaimer. ////
////                                                              ////
////                                                              ////
//// This source file is free software; you can redistribute it   ////
//// This source file is free software; you can redistribute it   ////
//// and/or modify it under the terms of the GNU Lesser General   ////
//// and/or modify it under the terms of the GNU Lesser General   ////
//// Public License as published by the Free Software Foundation; ////
//// Public License as published by the Free Software Foundation; ////
//// either version 2.1 of the License, or (at your option) any   ////
//// either version 2.1 of the License, or (at your option) any   ////
//// later version.                                               ////
//// later version.                                               ////
////                                                              ////
////                                                              ////
//// This source is distributed in the hope that it will be       ////
//// This source is distributed in the hope that it will be       ////
//// useful, but WITHOUT ANY WARRANTY; without even the implied   ////
//// useful, but WITHOUT ANY WARRANTY; without even the implied   ////
//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR      ////
//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR      ////
//// PURPOSE.  See the GNU Lesser General Public License for more ////
//// PURPOSE.  See the GNU Lesser General Public License for more ////
//// details.                                                     ////
//// details.                                                     ////
////                                                              ////
////                                                              ////
//// You should have received a copy of the GNU Lesser General    ////
//// You should have received a copy of the GNU Lesser General    ////
//// Public License along with this source; if not, download it   ////
//// Public License along with this source; if not, download it   ////
//// from http://www.opencores.org/lgpl.shtml                     ////
//// from http://www.opencores.org/lgpl.shtml                     ////
////                                                              ////
////                                                              ////
//////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////
//
//
//
//
// $Log: or1200_ctrl.v,v $
// $Log: or1200_ctrl.v,v $
// Revision 2.0  2010/06/30 11:00:00  ORSoC
// Revision 2.0  2010/06/30 11:00:00  ORSoC
// Major update: 
// Major update: 
// Structure reordered and bugs fixed. 
// Structure reordered and bugs fixed. 
 
 
// synopsys translate_off
// synopsys translate_off
`include "timescale.v"
`include "timescale.v"
// synopsys translate_on
// synopsys translate_on
`include "or1200_defines.v"
`include "or1200_defines.v"
 
 
module or1200_ctrl
module or1200_ctrl
  (
  (
   // Clock and reset
   // Clock and reset
   clk, rst,
   clk, rst,
 
 
   // Internal i/f
   // Internal i/f
   except_flushpipe, extend_flush, if_flushpipe, id_flushpipe, ex_flushpipe,
   except_flushpipe, extend_flush, if_flushpipe, id_flushpipe, ex_flushpipe,
   wb_flushpipe,
   wb_flushpipe,
   id_freeze, ex_freeze, wb_freeze, if_insn, id_insn, ex_insn, abort_mvspr,
   id_freeze, ex_freeze, wb_freeze, if_insn, id_insn, ex_insn, abort_mvspr,
   id_branch_op, ex_branch_op, ex_branch_taken, pc_we,
   id_branch_op, ex_branch_op, ex_branch_taken, pc_we,
   rf_addra, rf_addrb, rf_rda, rf_rdb, alu_op, mac_op, shrot_op, comp_op,
   rf_addra, rf_addrb, rf_rda, rf_rdb, alu_op, alu_op2, mac_op, shrot_op,
   rf_addrw, rfwb_op, fpu_op,
   comp_op, rf_addrw, rfwb_op, fpu_op,
   wb_insn, id_simm, ex_simm, id_branch_addrtarget, ex_branch_addrtarget, sel_a,
   wb_insn, id_simm, ex_simm, id_branch_addrtarget, ex_branch_addrtarget, sel_a,
   sel_b, id_lsu_op,
   sel_b, id_lsu_op,
   cust5_op, cust5_limm, id_pc, ex_pc, du_hwbkpt,
   cust5_op, cust5_limm, id_pc, ex_pc, du_hwbkpt,
   multicycle, wait_on, wbforw_valid, sig_syscall, sig_trap,
   multicycle, wait_on, wbforw_valid, sig_syscall, sig_trap,
   force_dslot_fetch, no_more_dslot, id_void, ex_void, ex_spr_read,
   force_dslot_fetch, no_more_dslot, id_void, ex_void, ex_spr_read,
   ex_spr_write,
   ex_spr_write,
   id_mac_op, id_macrc_op, ex_macrc_op, rfe, except_illegal, dc_no_writethrough
   id_mac_op, id_macrc_op, ex_macrc_op, rfe, except_illegal, dc_no_writethrough
   );
   );
 
 
//
//
// I/O
// I/O
//
//
input                                   clk;
input                                   clk;
input                                   rst;
input                                   rst;
input                                   id_freeze;
input                                   id_freeze;
input                                   ex_freeze /* verilator public */;
input                                   ex_freeze /* verilator public */;
input                                   wb_freeze /* verilator public */;
input                                   wb_freeze /* verilator public */;
output                                  if_flushpipe;
output                                  if_flushpipe;
output                                  id_flushpipe;
output                                  id_flushpipe;
output                                  ex_flushpipe;
output                                  ex_flushpipe;
output                                  wb_flushpipe;
output                                  wb_flushpipe;
input                                   extend_flush;
input                                   extend_flush;
input                                   except_flushpipe;
input                                   except_flushpipe;
input                           abort_mvspr ;
input                           abort_mvspr ;
input   [31:0]                   if_insn;
input   [31:0]                   if_insn;
output  [31:0]                   id_insn;
output  [31:0]                   id_insn;
output  [31:0]                   ex_insn /* verilator public */;
output  [31:0]                   ex_insn /* verilator public */;
output  [`OR1200_BRANCHOP_WIDTH-1:0]             ex_branch_op;
output  [`OR1200_BRANCHOP_WIDTH-1:0]             ex_branch_op;
output  [`OR1200_BRANCHOP_WIDTH-1:0]             id_branch_op;
output  [`OR1200_BRANCHOP_WIDTH-1:0]             id_branch_op;
input                                           ex_branch_taken;
input                                           ex_branch_taken;
output  [`OR1200_REGFILE_ADDR_WIDTH-1:0] rf_addrw;
output  [`OR1200_REGFILE_ADDR_WIDTH-1:0] rf_addrw;
output  [`OR1200_REGFILE_ADDR_WIDTH-1:0] rf_addra;
output  [`OR1200_REGFILE_ADDR_WIDTH-1:0] rf_addra;
output  [`OR1200_REGFILE_ADDR_WIDTH-1:0] rf_addrb;
output  [`OR1200_REGFILE_ADDR_WIDTH-1:0] rf_addrb;
output                                  rf_rda;
output                                  rf_rda;
output                                  rf_rdb;
output                                  rf_rdb;
output  [`OR1200_ALUOP_WIDTH-1:0]                alu_op;
output  [`OR1200_ALUOP_WIDTH-1:0]                alu_op;
 
output [`OR1200_ALUOP2_WIDTH-1:0]                alu_op2;
output  [`OR1200_MACOP_WIDTH-1:0]                mac_op;
output  [`OR1200_MACOP_WIDTH-1:0]                mac_op;
output  [`OR1200_SHROTOP_WIDTH-1:0]              shrot_op;
output  [`OR1200_SHROTOP_WIDTH-1:0]              shrot_op;
output  [`OR1200_RFWBOP_WIDTH-1:0]               rfwb_op;
output  [`OR1200_RFWBOP_WIDTH-1:0]               rfwb_op;
output  [`OR1200_FPUOP_WIDTH-1:0]                fpu_op;
output  [`OR1200_FPUOP_WIDTH-1:0]                fpu_op;
input                                   pc_we;
input                                   pc_we;
output  [31:0]                           wb_insn;
output  [31:0]                           wb_insn;
output  [31:2]                          id_branch_addrtarget;
output  [31:2]                          id_branch_addrtarget;
output  [31:2]                          ex_branch_addrtarget;
output  [31:2]                          ex_branch_addrtarget;
output  [`OR1200_SEL_WIDTH-1:0]          sel_a;
output  [`OR1200_SEL_WIDTH-1:0]          sel_a;
output  [`OR1200_SEL_WIDTH-1:0]          sel_b;
output  [`OR1200_SEL_WIDTH-1:0]          sel_b;
output  [`OR1200_LSUOP_WIDTH-1:0]                id_lsu_op;
output  [`OR1200_LSUOP_WIDTH-1:0]                id_lsu_op;
output  [`OR1200_COMPOP_WIDTH-1:0]               comp_op;
output  [`OR1200_COMPOP_WIDTH-1:0]               comp_op;
output  [`OR1200_MULTICYCLE_WIDTH-1:0]           multicycle;
output  [`OR1200_MULTICYCLE_WIDTH-1:0]           multicycle;
output  [`OR1200_WAIT_ON_WIDTH-1:0]              wait_on;
output  [`OR1200_WAIT_ON_WIDTH-1:0]              wait_on;
output  [4:0]                            cust5_op;
output  [4:0]                            cust5_op;
output  [5:0]                            cust5_limm;
output  [5:0]                            cust5_limm;
input   [31:0]                          id_pc;
input   [31:0]                          id_pc;
input   [31:0]                          ex_pc;
input   [31:0]                          ex_pc;
output  [31:0]                           id_simm;
output  [31:0]                           id_simm;
output  [31:0]                           ex_simm;
output  [31:0]                           ex_simm;
input                                   wbforw_valid;
input                                   wbforw_valid;
input                                   du_hwbkpt;
input                                   du_hwbkpt;
output                                  sig_syscall;
output                                  sig_syscall;
output                                  sig_trap;
output                                  sig_trap;
output                                  force_dslot_fetch;
output                                  force_dslot_fetch;
output                                  no_more_dslot;
output                                  no_more_dslot;
output                                  id_void;
output                                  id_void;
output                                  ex_void;
output                                  ex_void;
output                                  ex_spr_read;
output                                  ex_spr_read;
output                                  ex_spr_write;
output                                  ex_spr_write;
output  [`OR1200_MACOP_WIDTH-1:0]        id_mac_op;
output  [`OR1200_MACOP_WIDTH-1:0]        id_mac_op;
output                                  id_macrc_op;
output                                  id_macrc_op;
output                                  ex_macrc_op;
output                                  ex_macrc_op;
output                                  rfe;
output                                  rfe;
output                                  except_illegal;
output                                  except_illegal;
output                                  dc_no_writethrough;
output                                  dc_no_writethrough;
 
 
 
 
//
//
// Internal wires and regs
// Internal wires and regs
//
//
reg     [`OR1200_BRANCHOP_WIDTH-1:0]             id_branch_op;
reg     [`OR1200_BRANCHOP_WIDTH-1:0]             id_branch_op;
reg     [`OR1200_BRANCHOP_WIDTH-1:0]             ex_branch_op;
reg     [`OR1200_BRANCHOP_WIDTH-1:0]             ex_branch_op;
reg     [`OR1200_ALUOP_WIDTH-1:0]                alu_op;
reg     [`OR1200_ALUOP_WIDTH-1:0]                alu_op;
 
reg [`OR1200_ALUOP2_WIDTH-1:0]                   alu_op2;
wire                                    if_maci_op;
wire                                    if_maci_op;
`ifdef OR1200_MAC_IMPLEMENTED
`ifdef OR1200_MAC_IMPLEMENTED
reg     [`OR1200_MACOP_WIDTH-1:0]                ex_mac_op;
reg     [`OR1200_MACOP_WIDTH-1:0]                ex_mac_op;
reg     [`OR1200_MACOP_WIDTH-1:0]                id_mac_op;
reg     [`OR1200_MACOP_WIDTH-1:0]                id_mac_op;
wire    [`OR1200_MACOP_WIDTH-1:0]                mac_op;
wire    [`OR1200_MACOP_WIDTH-1:0]                mac_op;
reg                                     ex_macrc_op;
reg                                     ex_macrc_op;
`else
`else
wire    [`OR1200_MACOP_WIDTH-1:0]                mac_op;
wire    [`OR1200_MACOP_WIDTH-1:0]                mac_op;
wire                                    ex_macrc_op;
wire                                    ex_macrc_op;
`endif
`endif
reg     [`OR1200_SHROTOP_WIDTH-1:0]              shrot_op;
reg     [`OR1200_SHROTOP_WIDTH-1:0]              shrot_op;
reg     [31:0]                           id_insn /* verilator public */;
reg     [31:0]                           id_insn /* verilator public */;
reg     [31:0]                           ex_insn /* verilator public */;
reg     [31:0]                           ex_insn /* verilator public */;
reg     [31:0]                           wb_insn /* verilator public */;
reg     [31:0]                           wb_insn /* verilator public */;
reg     [`OR1200_REGFILE_ADDR_WIDTH-1:0] rf_addrw;
reg     [`OR1200_REGFILE_ADDR_WIDTH-1:0] rf_addrw;
reg     [`OR1200_REGFILE_ADDR_WIDTH-1:0] wb_rfaddrw;
reg     [`OR1200_REGFILE_ADDR_WIDTH-1:0] wb_rfaddrw;
reg     [`OR1200_RFWBOP_WIDTH-1:0]               rfwb_op;
reg     [`OR1200_RFWBOP_WIDTH-1:0]               rfwb_op;
reg     [`OR1200_SEL_WIDTH-1:0]          sel_a;
reg     [`OR1200_SEL_WIDTH-1:0]          sel_a;
reg     [`OR1200_SEL_WIDTH-1:0]          sel_b;
reg     [`OR1200_SEL_WIDTH-1:0]          sel_b;
reg                                     sel_imm;
reg                                     sel_imm;
reg     [`OR1200_LSUOP_WIDTH-1:0]                id_lsu_op;
reg     [`OR1200_LSUOP_WIDTH-1:0]                id_lsu_op;
reg     [`OR1200_COMPOP_WIDTH-1:0]               comp_op;
reg     [`OR1200_COMPOP_WIDTH-1:0]               comp_op;
reg     [`OR1200_MULTICYCLE_WIDTH-1:0]           multicycle;
reg     [`OR1200_MULTICYCLE_WIDTH-1:0]           multicycle;
reg     [`OR1200_WAIT_ON_WIDTH-1:0]              wait_on;
reg     [`OR1200_WAIT_ON_WIDTH-1:0]              wait_on;
reg     [31:0]                           id_simm;
reg     [31:0]                           id_simm;
reg     [31:0]                           ex_simm;
reg     [31:0]                           ex_simm;
reg                                     sig_syscall;
reg                                     sig_syscall;
reg                                     sig_trap;
reg                                     sig_trap;
reg                                     except_illegal;
reg                                     except_illegal;
wire                                    id_void;
wire                                    id_void;
wire                                    ex_void;
wire                                    ex_void;
wire                                    wb_void;
wire                                    wb_void;
reg                                     ex_delayslot_dsi;
reg                                     ex_delayslot_dsi;
reg                                     ex_delayslot_nop;
reg                                     ex_delayslot_nop;
reg                                     spr_read;
reg                                     spr_read;
reg                                     spr_write;
reg                                     spr_write;
reg     [31:2]                          ex_branch_addrtarget;
reg     [31:2]                          ex_branch_addrtarget;
`ifdef OR1200_DC_NOSTACKWRITETHROUGH
`ifdef OR1200_DC_NOSTACKWRITETHROUGH
reg                                     dc_no_writethrough;
reg                                     dc_no_writethrough;
`endif
`endif
 
 
//
//
// Register file read addresses
// Register file read addresses
//
//
assign rf_addra = if_insn[20:16];
assign rf_addra = if_insn[20:16];
assign rf_addrb = if_insn[15:11];
assign rf_addrb = if_insn[15:11];
assign rf_rda = if_insn[31] || if_maci_op;
assign rf_rda = if_insn[31] || if_maci_op;
assign rf_rdb = if_insn[30];
assign rf_rdb = if_insn[30];
 
 
//
//
// Force fetch of delay slot instruction when jump/branch is preceeded by load/store
// Force fetch of delay slot instruction when jump/branch is preceeded by load/store
// instructions
// instructions
//
//
assign force_dslot_fetch = 1'b0;
assign force_dslot_fetch = 1'b0;
assign no_more_dslot = (|ex_branch_op & !id_void & ex_branch_taken) | (ex_branch_op == `OR1200_BRANCHOP_RFE);
assign no_more_dslot = (|ex_branch_op & !id_void & ex_branch_taken) | (ex_branch_op == `OR1200_BRANCHOP_RFE);
 
 
assign id_void = (id_insn[31:26] == `OR1200_OR32_NOP) & id_insn[16];
assign id_void = (id_insn[31:26] == `OR1200_OR32_NOP) & id_insn[16];
assign ex_void = (ex_insn[31:26] == `OR1200_OR32_NOP) & ex_insn[16];
assign ex_void = (ex_insn[31:26] == `OR1200_OR32_NOP) & ex_insn[16];
assign wb_void = (wb_insn[31:26] == `OR1200_OR32_NOP) & wb_insn[16];
assign wb_void = (wb_insn[31:26] == `OR1200_OR32_NOP) & wb_insn[16];
 
 
assign ex_spr_write = spr_write && !abort_mvspr;
assign ex_spr_write = spr_write && !abort_mvspr;
assign ex_spr_read = spr_read && !abort_mvspr;
assign ex_spr_read = spr_read && !abort_mvspr;
 
 
//
//
// ex_delayslot_dsi: delay slot insn is in EX stage
// ex_delayslot_dsi: delay slot insn is in EX stage
// ex_delayslot_nop: (filler) nop insn is in EX stage (before nops jump/branch was executed)
// ex_delayslot_nop: (filler) nop insn is in EX stage (before nops jump/branch was executed)
//
//
//  ex_delayslot_dsi & !ex_delayslot_nop - DS insn in EX stage
//  ex_delayslot_dsi & !ex_delayslot_nop - DS insn in EX stage
//  !ex_delayslot_dsi & ex_delayslot_nop - NOP insn in EX stage, 
//  !ex_delayslot_dsi & ex_delayslot_nop - NOP insn in EX stage, 
//       next different is DS insn, previous different was Jump/Branch
//       next different is DS insn, previous different was Jump/Branch
//  !ex_delayslot_dsi & !ex_delayslot_nop - normal insn in EX stage
//  !ex_delayslot_dsi & !ex_delayslot_nop - normal insn in EX stage
//
//
always @(posedge clk or `OR1200_RST_EVENT rst) begin
always @(posedge clk or `OR1200_RST_EVENT rst) begin
        if (rst == `OR1200_RST_VALUE) begin
        if (rst == `OR1200_RST_VALUE) begin
                ex_delayslot_nop <=  1'b0;
                ex_delayslot_nop <=  1'b0;
                ex_delayslot_dsi <=  1'b0;
                ex_delayslot_dsi <=  1'b0;
        end
        end
        else if (!ex_freeze & !ex_delayslot_dsi & ex_delayslot_nop) begin
        else if (!ex_freeze & !ex_delayslot_dsi & ex_delayslot_nop) begin
                ex_delayslot_nop <=  id_void;
                ex_delayslot_nop <=  id_void;
                ex_delayslot_dsi <=  !id_void;
                ex_delayslot_dsi <=  !id_void;
        end
        end
        else if (!ex_freeze & ex_delayslot_dsi & !ex_delayslot_nop) begin
        else if (!ex_freeze & ex_delayslot_dsi & !ex_delayslot_nop) begin
                ex_delayslot_nop <=  1'b0;
                ex_delayslot_nop <=  1'b0;
                ex_delayslot_dsi <=  1'b0;
                ex_delayslot_dsi <=  1'b0;
        end
        end
        else if (!ex_freeze) begin
        else if (!ex_freeze) begin
                ex_delayslot_nop <=  id_void && ex_branch_taken && (ex_branch_op != `OR1200_BRANCHOP_NOP) &&
                ex_delayslot_nop <=  id_void && ex_branch_taken && (ex_branch_op != `OR1200_BRANCHOP_NOP) &&
                                                                (ex_branch_op != `OR1200_BRANCHOP_RFE);
                                                                (ex_branch_op != `OR1200_BRANCHOP_RFE);
                ex_delayslot_dsi <=  !id_void && ex_branch_taken && (ex_branch_op != `OR1200_BRANCHOP_NOP) &&
                ex_delayslot_dsi <=  !id_void && ex_branch_taken && (ex_branch_op != `OR1200_BRANCHOP_NOP) &&
                                                                 (ex_branch_op != `OR1200_BRANCHOP_RFE);
                                                                 (ex_branch_op != `OR1200_BRANCHOP_RFE);
        end
        end
end
end
 
 
//
//
// Flush pipeline
// Flush pipeline
//
//
assign if_flushpipe = except_flushpipe | pc_we | extend_flush;
assign if_flushpipe = except_flushpipe | pc_we | extend_flush;
assign id_flushpipe = except_flushpipe | pc_we | extend_flush;
assign id_flushpipe = except_flushpipe | pc_we | extend_flush;
assign ex_flushpipe = except_flushpipe | pc_we | extend_flush;
assign ex_flushpipe = except_flushpipe | pc_we | extend_flush;
assign wb_flushpipe = except_flushpipe | pc_we | extend_flush;
assign wb_flushpipe = except_flushpipe | pc_we | extend_flush;
 
 
//
//
// EX Sign/Zero extension of immediates
// EX Sign/Zero extension of immediates
//
//
always @(posedge clk or `OR1200_RST_EVENT rst) begin
always @(posedge clk or `OR1200_RST_EVENT rst) begin
        if (rst == `OR1200_RST_VALUE)
        if (rst == `OR1200_RST_VALUE)
                ex_simm <=  32'h0000_0000;
                ex_simm <=  32'h0000_0000;
        else if (!ex_freeze) begin
        else if (!ex_freeze) begin
                ex_simm <=  id_simm;
                ex_simm <=  id_simm;
        end
        end
end
end
 
 
//
//
// ID Sign/Zero extension of immediate
// ID Sign/Zero extension of immediate
//
//
always @(id_insn) begin
always @(id_insn) begin
        case (id_insn[31:26])     // synopsys parallel_case
        case (id_insn[31:26])     // synopsys parallel_case
 
 
        // l.addi
        // l.addi
        `OR1200_OR32_ADDI:
        `OR1200_OR32_ADDI:
                id_simm = {{16{id_insn[15]}}, id_insn[15:0]};
                id_simm = {{16{id_insn[15]}}, id_insn[15:0]};
 
 
        // l.addic
        // l.addic
        `OR1200_OR32_ADDIC:
        `OR1200_OR32_ADDIC:
                id_simm = {{16{id_insn[15]}}, id_insn[15:0]};
                id_simm = {{16{id_insn[15]}}, id_insn[15:0]};
 
 
        // l.lxx (load instructions)
        // l.lxx (load instructions)
        `OR1200_OR32_LWZ, `OR1200_OR32_LBZ, `OR1200_OR32_LBS, `OR1200_OR32_LHZ, `OR1200_OR32_LHS:
        `OR1200_OR32_LWZ, `OR1200_OR32_LBZ, `OR1200_OR32_LBS, `OR1200_OR32_LHZ, `OR1200_OR32_LHS:
                id_simm = {{16{id_insn[15]}}, id_insn[15:0]};
                id_simm = {{16{id_insn[15]}}, id_insn[15:0]};
 
 
        // l.muli
        // l.muli
        `ifdef OR1200_MULT_IMPLEMENTED
        `ifdef OR1200_MULT_IMPLEMENTED
        `OR1200_OR32_MULI:
        `OR1200_OR32_MULI:
                id_simm = {{16{id_insn[15]}}, id_insn[15:0]};
                id_simm = {{16{id_insn[15]}}, id_insn[15:0]};
        `endif
        `endif
 
 
        // l.maci
        // l.maci
        `ifdef OR1200_MAC_IMPLEMENTED
        `ifdef OR1200_MAC_IMPLEMENTED
        `OR1200_OR32_MACI:
        `OR1200_OR32_MACI:
                id_simm = {{16{id_insn[25]}}, id_insn[25:21], id_insn[10:0]};
                id_simm = {{16{id_insn[25]}}, id_insn[25:21], id_insn[10:0]};
        `endif
        `endif
 
 
        // l.mtspr
        // l.mtspr
        `OR1200_OR32_MTSPR:
        `OR1200_OR32_MTSPR:
                id_simm = {16'b0, id_insn[25:21], id_insn[10:0]};
                id_simm = {16'b0, id_insn[25:21], id_insn[10:0]};
 
 
        // l.sxx (store instructions)
        // l.sxx (store instructions)
        `OR1200_OR32_SW, `OR1200_OR32_SH, `OR1200_OR32_SB:
        `OR1200_OR32_SW, `OR1200_OR32_SH, `OR1200_OR32_SB:
                id_simm = {{16{id_insn[25]}}, id_insn[25:21], id_insn[10:0]};
                id_simm = {{16{id_insn[25]}}, id_insn[25:21], id_insn[10:0]};
 
 
        // l.xori
        // l.xori
        `OR1200_OR32_XORI:
        `OR1200_OR32_XORI:
                id_simm = {{16{id_insn[15]}}, id_insn[15:0]};
                id_simm = {{16{id_insn[15]}}, id_insn[15:0]};
 
 
        // l.sfxxi (SFXX with immediate)
        // l.sfxxi (SFXX with immediate)
        `OR1200_OR32_SFXXI:
        `OR1200_OR32_SFXXI:
                id_simm = {{16{id_insn[15]}}, id_insn[15:0]};
                id_simm = {{16{id_insn[15]}}, id_insn[15:0]};
 
 
        // Instructions with no or zero extended immediate
        // Instructions with no or zero extended immediate
        default:
        default:
                id_simm = {{16'b0}, id_insn[15:0]};
                id_simm = {{16'b0}, id_insn[15:0]};
 
 
        endcase
        endcase
end
end
 
 
//
//
// ID Sign extension of branch offset
// ID Sign extension of branch offset
//
//
assign id_branch_addrtarget = {{4{id_insn[25]}}, id_insn[25:0]} + id_pc[31:2];
assign id_branch_addrtarget = {{4{id_insn[25]}}, id_insn[25:0]} + id_pc[31:2];
 
 
//
//
// EX Sign extension of branch offset
// EX Sign extension of branch offset
//
//
 
 
// pipeline ID and EX branch target address 
// pipeline ID and EX branch target address 
always @(posedge clk or `OR1200_RST_EVENT rst) begin
always @(posedge clk or `OR1200_RST_EVENT rst) begin
        if (rst == `OR1200_RST_VALUE)
        if (rst == `OR1200_RST_VALUE)
                ex_branch_addrtarget <=  0;
                ex_branch_addrtarget <=  0;
        else if (!ex_freeze)
        else if (!ex_freeze)
                ex_branch_addrtarget <=  id_branch_addrtarget;
                ex_branch_addrtarget <=  id_branch_addrtarget;
end
end
// not pipelined
// not pipelined
//assign ex_branch_addrtarget = {{4{ex_insn[25]}}, ex_insn[25:0]} + ex_pc[31:2];
//assign ex_branch_addrtarget = {{4{ex_insn[25]}}, ex_insn[25:0]} + ex_pc[31:2];
 
 
//
//
// l.maci in IF stage
// l.maci in IF stage
//
//
`ifdef OR1200_MAC_IMPLEMENTED
`ifdef OR1200_MAC_IMPLEMENTED
assign if_maci_op = (if_insn[31:26] == `OR1200_OR32_MACI);
assign if_maci_op = (if_insn[31:26] == `OR1200_OR32_MACI);
`else
`else
assign if_maci_op = 1'b0;
assign if_maci_op = 1'b0;
`endif
`endif
 
 
//
//
// l.macrc in ID stage
// l.macrc in ID stage
//
//
`ifdef OR1200_MAC_IMPLEMENTED
`ifdef OR1200_MAC_IMPLEMENTED
assign id_macrc_op = (id_insn[31:26] == `OR1200_OR32_MOVHI) & id_insn[16];
assign id_macrc_op = (id_insn[31:26] == `OR1200_OR32_MOVHI) & id_insn[16];
`else
`else
assign id_macrc_op = 1'b0;
assign id_macrc_op = 1'b0;
`endif
`endif
 
 
//
//
// l.macrc in EX stage
// l.macrc in EX stage
//
//
`ifdef OR1200_MAC_IMPLEMENTED
`ifdef OR1200_MAC_IMPLEMENTED
always @(posedge clk or `OR1200_RST_EVENT rst) begin
always @(posedge clk or `OR1200_RST_EVENT rst) begin
        if (rst == `OR1200_RST_VALUE)
        if (rst == `OR1200_RST_VALUE)
                ex_macrc_op <=  1'b0;
                ex_macrc_op <=  1'b0;
        else if (!ex_freeze & id_freeze | ex_flushpipe)
        else if (!ex_freeze & id_freeze | ex_flushpipe)
                ex_macrc_op <=  1'b0;
                ex_macrc_op <=  1'b0;
        else if (!ex_freeze)
        else if (!ex_freeze)
                ex_macrc_op <=  id_macrc_op;
                ex_macrc_op <=  id_macrc_op;
end
end
`else
`else
assign ex_macrc_op = 1'b0;
assign ex_macrc_op = 1'b0;
`endif
`endif
 
 
//
//
// cust5_op, cust5_limm (L immediate)
// cust5_op, cust5_limm (L immediate)
//
//
assign cust5_op = ex_insn[4:0];
assign cust5_op = ex_insn[4:0];
assign cust5_limm = ex_insn[10:5];
assign cust5_limm = ex_insn[10:5];
 
 
//
//
//
//
//
//
assign rfe = (id_branch_op == `OR1200_BRANCHOP_RFE) | (ex_branch_op == `OR1200_BRANCHOP_RFE);
assign rfe = (id_branch_op == `OR1200_BRANCHOP_RFE) | (ex_branch_op == `OR1200_BRANCHOP_RFE);
 
 
 
 
`ifdef verilator
`ifdef verilator
   // Function to access wb_insn (for Verilator). Have to hide this from
   // Function to access wb_insn (for Verilator). Have to hide this from
   // simulator, since functions with no inputs are not allowed in IEEE
   // simulator, since functions with no inputs are not allowed in IEEE
   // 1364-2001.
   // 1364-2001.
   function [31:0] get_wb_insn;
   function [31:0] get_wb_insn;
      // verilator public
      // verilator public
      get_wb_insn = wb_insn;
      get_wb_insn = wb_insn;
   endfunction // get_wb_insn
   endfunction // get_wb_insn
 
 
   // Function to access id_insn (for Verilator). Have to hide this from
   // Function to access id_insn (for Verilator). Have to hide this from
   // simulator, since functions with no inputs are not allowed in IEEE
   // simulator, since functions with no inputs are not allowed in IEEE
   // 1364-2001.
   // 1364-2001.
   function [31:0] get_id_insn;
   function [31:0] get_id_insn;
      // verilator public
      // verilator public
      get_id_insn = id_insn;
      get_id_insn = id_insn;
   endfunction // get_id_insn
   endfunction // get_id_insn
 
 
   // Function to access ex_insn (for Verilator). Have to hide this from
   // Function to access ex_insn (for Verilator). Have to hide this from
   // simulator, since functions with no inputs are not allowed in IEEE
   // simulator, since functions with no inputs are not allowed in IEEE
   // 1364-2001.
   // 1364-2001.
   function [31:0] get_ex_insn;
   function [31:0] get_ex_insn;
      // verilator public
      // verilator public
      get_ex_insn = ex_insn;
      get_ex_insn = ex_insn;
   endfunction // get_ex_insn
   endfunction // get_ex_insn
 
 
`endif
`endif
 
 
 
 
//
//
// Generation of sel_a
// Generation of sel_a
//
//
always @(rf_addrw or id_insn or rfwb_op or wbforw_valid or wb_rfaddrw)
always @(rf_addrw or id_insn or rfwb_op or wbforw_valid or wb_rfaddrw)
        if ((id_insn[20:16] == rf_addrw) && rfwb_op[0])
        if ((id_insn[20:16] == rf_addrw) && rfwb_op[0])
                sel_a = `OR1200_SEL_EX_FORW;
                sel_a = `OR1200_SEL_EX_FORW;
        else if ((id_insn[20:16] == wb_rfaddrw) && wbforw_valid)
        else if ((id_insn[20:16] == wb_rfaddrw) && wbforw_valid)
                sel_a = `OR1200_SEL_WB_FORW;
                sel_a = `OR1200_SEL_WB_FORW;
        else
        else
                sel_a = `OR1200_SEL_RF;
                sel_a = `OR1200_SEL_RF;
 
 
//
//
// Generation of sel_b
// Generation of sel_b
//
//
always @(rf_addrw or sel_imm or id_insn or rfwb_op or wbforw_valid or wb_rfaddrw)
always @(rf_addrw or sel_imm or id_insn or rfwb_op or wbforw_valid or wb_rfaddrw)
        if (sel_imm)
        if (sel_imm)
                sel_b = `OR1200_SEL_IMM;
                sel_b = `OR1200_SEL_IMM;
        else if ((id_insn[15:11] == rf_addrw) && rfwb_op[0])
        else if ((id_insn[15:11] == rf_addrw) && rfwb_op[0])
                sel_b = `OR1200_SEL_EX_FORW;
                sel_b = `OR1200_SEL_EX_FORW;
        else if ((id_insn[15:11] == wb_rfaddrw) && wbforw_valid)
        else if ((id_insn[15:11] == wb_rfaddrw) && wbforw_valid)
                sel_b = `OR1200_SEL_WB_FORW;
                sel_b = `OR1200_SEL_WB_FORW;
        else
        else
                sel_b = `OR1200_SEL_RF;
                sel_b = `OR1200_SEL_RF;
 
 
//
//
// Decode of multicycle
// Decode of multicycle
//
//
always @(id_insn) begin
always @(id_insn) begin
  case (id_insn[31:26])         // synopsys parallel_case
  case (id_insn[31:26])         // synopsys parallel_case
`ifdef UNUSED
`ifdef UNUSED
    // l.lwz
    // l.lwz
    `OR1200_OR32_LWZ:
    `OR1200_OR32_LWZ:
      multicycle = `OR1200_TWO_CYCLES;
      multicycle = `OR1200_TWO_CYCLES;
 
 
    // l.lbz
    // l.lbz
    `OR1200_OR32_LBZ:
    `OR1200_OR32_LBZ:
      multicycle = `OR1200_TWO_CYCLES;
      multicycle = `OR1200_TWO_CYCLES;
 
 
    // l.lbs
    // l.lbs
    `OR1200_OR32_LBS:
    `OR1200_OR32_LBS:
      multicycle = `OR1200_TWO_CYCLES;
      multicycle = `OR1200_TWO_CYCLES;
 
 
    // l.lhz
    // l.lhz
    `OR1200_OR32_LHZ:
    `OR1200_OR32_LHZ:
      multicycle = `OR1200_TWO_CYCLES;
      multicycle = `OR1200_TWO_CYCLES;
 
 
    // l.lhs
    // l.lhs
    `OR1200_OR32_LHS:
    `OR1200_OR32_LHS:
      multicycle = `OR1200_TWO_CYCLES;
      multicycle = `OR1200_TWO_CYCLES;
 
 
    // l.sw
    // l.sw
    `OR1200_OR32_SW:
    `OR1200_OR32_SW:
      multicycle = `OR1200_TWO_CYCLES;
      multicycle = `OR1200_TWO_CYCLES;
 
 
    // l.sb
    // l.sb
    `OR1200_OR32_SB:
    `OR1200_OR32_SB:
      multicycle = `OR1200_TWO_CYCLES;
      multicycle = `OR1200_TWO_CYCLES;
 
 
    // l.sh
    // l.sh
    `OR1200_OR32_SH:
    `OR1200_OR32_SH:
      multicycle = `OR1200_TWO_CYCLES;
      multicycle = `OR1200_TWO_CYCLES;
`endif
`endif
    // l.mfspr
    // l.mfspr
    `OR1200_OR32_MFSPR:
    `OR1200_OR32_MFSPR:
      multicycle = `OR1200_TWO_CYCLES;  // to read from ITLB/DTLB (sync RAMs)
      multicycle = `OR1200_TWO_CYCLES;  // to read from ITLB/DTLB (sync RAMs)
 
 
    // ALU instructions except the one with immediate
    // ALU instructions except the one with immediate
    `OR1200_OR32_ALU:
    `OR1200_OR32_ALU:
        case (id_insn[3:0]) // synopsys parallel_case
        case (id_insn[3:0]) // synopsys parallel_case
        4'h6: multicycle = `OR1200_MULTICYCLE_WIDTH'd3; // l.mul
        4'h6: multicycle = `OR1200_MULTICYCLE_WIDTH'd3; // l.mul
        4'h9: multicycle = `OR1200_MULTICYCLE_WIDTH'd2; // l.div
        4'h9: multicycle = `OR1200_MULTICYCLE_WIDTH'd2; // l.div
        4'hA: multicycle = `OR1200_MULTICYCLE_WIDTH'd2; // l.divu
        4'hA: multicycle = `OR1200_MULTICYCLE_WIDTH'd2; // l.divu
        4'hB: multicycle = `OR1200_MULTICYCLE_WIDTH'd3; // l.mulu
        4'hB: multicycle = `OR1200_MULTICYCLE_WIDTH'd3; // l.mulu
        default: multicycle = `OR1200_MULTICYCLE_WIDTH'd0;
        default: multicycle = `OR1200_MULTICYCLE_WIDTH'd0;
        endcase
        endcase
    `OR1200_OR32_MULI:
    `OR1200_OR32_MULI:
      multicycle = `OR1200_MULTICYCLE_WIDTH'd3;
      multicycle = `OR1200_MULTICYCLE_WIDTH'd3;
 
 
    // Single cycle instructions
    // Single cycle instructions
    default: begin
    default: begin
      multicycle = `OR1200_ONE_CYCLE;
      multicycle = `OR1200_ONE_CYCLE;
    end
    end
  endcase
  endcase
end // always @ (id_insn)
end // always @ (id_insn)
 
 
//
//
// Encode wait_on signal
// Encode wait_on signal
//    
//    
always @(id_insn) begin
always @(id_insn) begin
   case (id_insn[31:26])                // synopsys parallel_case
   case (id_insn[31:26])                // synopsys parallel_case
`ifdef OR1200_FPU_IMPLEMENTED
`ifdef OR1200_FPU_IMPLEMENTED
       `OR1200_OR32_FLOAT: begin
       `OR1200_OR32_FLOAT: begin
         wait_on = id_insn[`OR1200_FPUOP_DOUBLE_BIT] ? 0 : `OR1200_WAIT_ON_FPU;
         wait_on = id_insn[`OR1200_FPUOP_DOUBLE_BIT] ? 0 : `OR1200_WAIT_ON_FPU;
       end
       end
`endif
`endif
`ifndef OR1200_DC_WRITHROUGH
`ifndef OR1200_DC_WRITHROUGH
     // l.mtspr
     // l.mtspr
     `OR1200_OR32_MTSPR: begin
     `OR1200_OR32_MTSPR: begin
        wait_on = `OR1200_WAIT_ON_MTSPR;
        wait_on = `OR1200_WAIT_ON_MTSPR;
     end
     end
`endif
`endif
     default: begin
     default: begin
        wait_on = 0;
        wait_on = 0;
     end
     end
   endcase // case (id_insn[31:26])
   endcase // case (id_insn[31:26])
end // always @ (id_insn)
end // always @ (id_insn)
 
 
 
 
 
 
 
 
//
//
// Register file write address
// Register file write address
//
//
always @(posedge clk or `OR1200_RST_EVENT rst) begin
always @(posedge clk or `OR1200_RST_EVENT rst) begin
        if (rst == `OR1200_RST_VALUE)
        if (rst == `OR1200_RST_VALUE)
                rf_addrw <=  5'd0;
                rf_addrw <=  5'd0;
        else if (!ex_freeze & id_freeze)
        else if (!ex_freeze & id_freeze)
                rf_addrw <=  5'd00;
                rf_addrw <=  5'd00;
        else if (!ex_freeze)
        else if (!ex_freeze)
                case (id_insn[31:26])   // synopsys parallel_case
                case (id_insn[31:26])   // synopsys parallel_case
                        `OR1200_OR32_JAL, `OR1200_OR32_JALR:
                        `OR1200_OR32_JAL, `OR1200_OR32_JALR:
                                rf_addrw <=  5'd09;     // link register r9
                                rf_addrw <=  5'd09;     // link register r9
                        default:
                        default:
                                rf_addrw <=  id_insn[25:21];
                                rf_addrw <=  id_insn[25:21];
                endcase
                endcase
end
end
 
 
//
//
// rf_addrw in wb stage (used in forwarding logic)
// rf_addrw in wb stage (used in forwarding logic)
//
//
always @(posedge clk or `OR1200_RST_EVENT rst) begin
always @(posedge clk or `OR1200_RST_EVENT rst) begin
        if (rst == `OR1200_RST_VALUE)
        if (rst == `OR1200_RST_VALUE)
                wb_rfaddrw <=  5'd0;
                wb_rfaddrw <=  5'd0;
        else if (!wb_freeze)
        else if (!wb_freeze)
                wb_rfaddrw <=  rf_addrw;
                wb_rfaddrw <=  rf_addrw;
end
end
 
 
//
//
// Instruction latch in id_insn
// Instruction latch in id_insn
//
//
always @(posedge clk or `OR1200_RST_EVENT rst) begin
always @(posedge clk or `OR1200_RST_EVENT rst) begin
        if (rst == `OR1200_RST_VALUE)
        if (rst == `OR1200_RST_VALUE)
                id_insn <=  {`OR1200_OR32_NOP, 26'h041_0000};
                id_insn <=  {`OR1200_OR32_NOP, 26'h041_0000};
        else if (id_flushpipe)
        else if (id_flushpipe)
                id_insn <=  {`OR1200_OR32_NOP, 26'h041_0000};        // NOP -> id_insn[16] must be 1
                id_insn <=  {`OR1200_OR32_NOP, 26'h041_0000};        // NOP -> id_insn[16] must be 1
        else if (!id_freeze) begin
        else if (!id_freeze) begin
                id_insn <=  if_insn;
                id_insn <=  if_insn;
`ifdef OR1200_VERBOSE
`ifdef OR1200_VERBOSE
// synopsys translate_off
// synopsys translate_off
                $display("%t: id_insn <= %h", $time, if_insn);
                $display("%t: id_insn <= %h", $time, if_insn);
// synopsys translate_on
// synopsys translate_on
`endif
`endif
        end
        end
end
end
 
 
//
//
// Instruction latch in ex_insn
// Instruction latch in ex_insn
//
//
always @(posedge clk or `OR1200_RST_EVENT rst) begin
always @(posedge clk or `OR1200_RST_EVENT rst) begin
        if (rst == `OR1200_RST_VALUE)
        if (rst == `OR1200_RST_VALUE)
                ex_insn <=  {`OR1200_OR32_NOP, 26'h041_0000};
                ex_insn <=  {`OR1200_OR32_NOP, 26'h041_0000};
        else if (!ex_freeze & id_freeze | ex_flushpipe)
        else if (!ex_freeze & id_freeze | ex_flushpipe)
                ex_insn <=  {`OR1200_OR32_NOP, 26'h041_0000};   // NOP -> ex_insn[16] must be 1
                ex_insn <=  {`OR1200_OR32_NOP, 26'h041_0000};   // NOP -> ex_insn[16] must be 1
        else if (!ex_freeze) begin
        else if (!ex_freeze) begin
                ex_insn <=  id_insn;
                ex_insn <=  id_insn;
`ifdef OR1200_VERBOSE
`ifdef OR1200_VERBOSE
// synopsys translate_off
// synopsys translate_off
                $display("%t: ex_insn <= %h", $time, id_insn);
                $display("%t: ex_insn <= %h", $time, id_insn);
// synopsys translate_on
// synopsys translate_on
`endif
`endif
        end
        end
end
end
 
 
//
//
// Instruction latch in wb_insn
// Instruction latch in wb_insn
//
//
always @(posedge clk or `OR1200_RST_EVENT rst) begin
always @(posedge clk or `OR1200_RST_EVENT rst) begin
        if (rst == `OR1200_RST_VALUE)
        if (rst == `OR1200_RST_VALUE)
                wb_insn <=  {`OR1200_OR32_NOP, 26'h041_0000};
                wb_insn <=  {`OR1200_OR32_NOP, 26'h041_0000};
        // wb_insn should not be changed by exceptions due to correct 
        // wb_insn should not be changed by exceptions due to correct 
        // recording of display_arch_state in the or1200_monitor! 
        // recording of display_arch_state in the or1200_monitor! 
        // wb_insn changed by exception is not used elsewhere! 
        // wb_insn changed by exception is not used elsewhere! 
        else if (!wb_freeze) begin
        else if (!wb_freeze) begin
                wb_insn <=  ex_insn;
                wb_insn <=  ex_insn;
        end
        end
end
end
 
 
//
//
// Decode of sel_imm
// Decode of sel_imm
//
//
always @(posedge clk or `OR1200_RST_EVENT rst) begin
always @(posedge clk or `OR1200_RST_EVENT rst) begin
        if (rst == `OR1200_RST_VALUE)
        if (rst == `OR1200_RST_VALUE)
                sel_imm <=  1'b0;
                sel_imm <=  1'b0;
        else if (!id_freeze) begin
        else if (!id_freeze) begin
          case (if_insn[31:26])         // synopsys parallel_case
          case (if_insn[31:26])         // synopsys parallel_case
 
 
            // j.jalr
            // j.jalr
            `OR1200_OR32_JALR:
            `OR1200_OR32_JALR:
              sel_imm <=  1'b0;
              sel_imm <=  1'b0;
 
 
            // l.jr
            // l.jr
            `OR1200_OR32_JR:
            `OR1200_OR32_JR:
              sel_imm <=  1'b0;
              sel_imm <=  1'b0;
 
 
            // l.rfe
            // l.rfe
            `OR1200_OR32_RFE:
            `OR1200_OR32_RFE:
              sel_imm <=  1'b0;
              sel_imm <=  1'b0;
 
 
            // l.mfspr
            // l.mfspr
            `OR1200_OR32_MFSPR:
            `OR1200_OR32_MFSPR:
              sel_imm <=  1'b0;
              sel_imm <=  1'b0;
 
 
            // l.mtspr
            // l.mtspr
            `OR1200_OR32_MTSPR:
            `OR1200_OR32_MTSPR:
              sel_imm <=  1'b0;
              sel_imm <=  1'b0;
 
 
            // l.sys, l.brk and all three sync insns
            // l.sys, l.brk and all three sync insns
            `OR1200_OR32_XSYNC:
            `OR1200_OR32_XSYNC:
              sel_imm <=  1'b0;
              sel_imm <=  1'b0;
 
 
            // l.mac/l.msb
            // l.mac/l.msb
`ifdef OR1200_MAC_IMPLEMENTED
`ifdef OR1200_MAC_IMPLEMENTED
            `OR1200_OR32_MACMSB:
            `OR1200_OR32_MACMSB:
              sel_imm <=  1'b0;
              sel_imm <=  1'b0;
`endif
`endif
 
 
            // l.sw
            // l.sw
            `OR1200_OR32_SW:
            `OR1200_OR32_SW:
              sel_imm <=  1'b0;
              sel_imm <=  1'b0;
 
 
            // l.sb
            // l.sb
            `OR1200_OR32_SB:
            `OR1200_OR32_SB:
              sel_imm <=  1'b0;
              sel_imm <=  1'b0;
 
 
            // l.sh
            // l.sh
            `OR1200_OR32_SH:
            `OR1200_OR32_SH:
              sel_imm <=  1'b0;
              sel_imm <=  1'b0;
 
 
            // ALU instructions except the one with immediate
            // ALU instructions except the one with immediate
            `OR1200_OR32_ALU:
            `OR1200_OR32_ALU:
              sel_imm <=  1'b0;
              sel_imm <=  1'b0;
 
 
            // SFXX instructions
            // SFXX instructions
            `OR1200_OR32_SFXX:
            `OR1200_OR32_SFXX:
              sel_imm <=  1'b0;
              sel_imm <=  1'b0;
 
 
`ifdef OR1200_OR32_CUST5
`ifdef OR1200_OR32_CUST5
            // l.cust5 instructions
            // l.cust5 instructions
            `OR1200_OR32_CUST5:
            `OR1200_OR32_CUST5:
              sel_imm <=  1'b0;
              sel_imm <=  1'b0;
`endif
`endif
`ifdef OR1200_FPU_IMPLEMENTED
`ifdef OR1200_FPU_IMPLEMENTED
            // FPU instructions
            // FPU instructions
            `OR1200_OR32_FLOAT:
            `OR1200_OR32_FLOAT:
              sel_imm <=  1'b0;
              sel_imm <=  1'b0;
`endif
`endif
            // l.nop
            // l.nop
            `OR1200_OR32_NOP:
            `OR1200_OR32_NOP:
              sel_imm <=  1'b0;
              sel_imm <=  1'b0;
 
 
            // All instructions with immediates
            // All instructions with immediates
            default: begin
            default: begin
              sel_imm <=  1'b1;
              sel_imm <=  1'b1;
            end
            end
 
 
          endcase
          endcase
 
 
        end
        end
end
end
 
 
//
//
// Decode of except_illegal
// Decode of except_illegal
//
//
always @(posedge clk or `OR1200_RST_EVENT rst) begin
always @(posedge clk or `OR1200_RST_EVENT rst) begin
        if (rst == `OR1200_RST_VALUE)
        if (rst == `OR1200_RST_VALUE)
                except_illegal <=  1'b0;
                except_illegal <=  1'b0;
        else if (!ex_freeze & id_freeze | ex_flushpipe)
        else if (!ex_freeze & id_freeze | ex_flushpipe)
                except_illegal <=  1'b0;
                except_illegal <=  1'b0;
        else if (!ex_freeze) begin
        else if (!ex_freeze) begin
                case (id_insn[31:26])           // synopsys parallel_case
                case (id_insn[31:26])           // synopsys parallel_case
 
 
                `OR1200_OR32_J,
                `OR1200_OR32_J,
                `OR1200_OR32_JAL,
                `OR1200_OR32_JAL,
                `OR1200_OR32_JALR,
                `OR1200_OR32_JALR,
                `OR1200_OR32_JR,
                `OR1200_OR32_JR,
                `OR1200_OR32_BNF,
                `OR1200_OR32_BNF,
                `OR1200_OR32_BF,
                `OR1200_OR32_BF,
                `OR1200_OR32_RFE,
                `OR1200_OR32_RFE,
                `OR1200_OR32_MOVHI,
                `OR1200_OR32_MOVHI,
                `OR1200_OR32_MFSPR,
                `OR1200_OR32_MFSPR,
                `OR1200_OR32_XSYNC,
                `OR1200_OR32_XSYNC,
`ifdef OR1200_MAC_IMPLEMENTED
`ifdef OR1200_MAC_IMPLEMENTED
                `OR1200_OR32_MACI,
                `OR1200_OR32_MACI,
`endif
`endif
                `OR1200_OR32_LWZ,
                `OR1200_OR32_LWZ,
                `OR1200_OR32_LBZ,
                `OR1200_OR32_LBZ,
                `OR1200_OR32_LBS,
                `OR1200_OR32_LBS,
                `OR1200_OR32_LHZ,
                `OR1200_OR32_LHZ,
                `OR1200_OR32_LHS,
                `OR1200_OR32_LHS,
                `OR1200_OR32_ADDI,
                `OR1200_OR32_ADDI,
                `OR1200_OR32_ADDIC,
                `OR1200_OR32_ADDIC,
                `OR1200_OR32_ANDI,
                `OR1200_OR32_ANDI,
                `OR1200_OR32_ORI,
                `OR1200_OR32_ORI,
                `OR1200_OR32_XORI,
                `OR1200_OR32_XORI,
`ifdef OR1200_MULT_IMPLEMENTED
`ifdef OR1200_MULT_IMPLEMENTED
                `OR1200_OR32_MULI,
                `OR1200_OR32_MULI,
`endif
`endif
                `OR1200_OR32_SH_ROTI,
                `OR1200_OR32_SH_ROTI,
                `OR1200_OR32_SFXXI,
                `OR1200_OR32_SFXXI,
                `OR1200_OR32_MTSPR,
                `OR1200_OR32_MTSPR,
`ifdef OR1200_MAC_IMPLEMENTED
`ifdef OR1200_MAC_IMPLEMENTED
                `OR1200_OR32_MACMSB,
                `OR1200_OR32_MACMSB,
`endif
`endif
                `OR1200_OR32_SW,
                `OR1200_OR32_SW,
                `OR1200_OR32_SB,
                `OR1200_OR32_SB,
                `OR1200_OR32_SH,
                `OR1200_OR32_SH,
                `OR1200_OR32_SFXX,
                `OR1200_OR32_SFXX,
`ifdef OR1200_OR32_CUST5
`ifdef OR1200_OR32_CUST5
                `OR1200_OR32_CUST5,
                `OR1200_OR32_CUST5,
`endif
`endif
        `OR1200_OR32_NOP:
        `OR1200_OR32_NOP:
                except_illegal <=  1'b0;
                except_illegal <=  1'b0;
`ifdef OR1200_FPU_IMPLEMENTED
`ifdef OR1200_FPU_IMPLEMENTED
            `OR1200_OR32_FLOAT:
            `OR1200_OR32_FLOAT:
                // Check it's not a double precision instruction
                // Check it's not a double precision instruction
                except_illegal <=  id_insn[`OR1200_FPUOP_DOUBLE_BIT];
                except_illegal <=  id_insn[`OR1200_FPUOP_DOUBLE_BIT];
`endif
`endif
 
 
        `OR1200_OR32_ALU:
        `OR1200_OR32_ALU:
                except_illegal <=  1'b0
                except_illegal <=  1'b0
 
 
`ifdef OR1200_MULT_IMPLEMENTED
`ifdef OR1200_MULT_IMPLEMENTED
`ifdef OR1200_DIV_IMPLEMENTED
`ifdef OR1200_DIV_IMPLEMENTED
`else
`else
                | (id_insn[3:0] == `OR1200_ALUOP_DIV)
                | (id_insn[3:0] == `OR1200_ALUOP_DIV)
                | (id_insn[3:0] == `OR1200_ALUOP_DIVU)
                | (id_insn[3:0] == `OR1200_ALUOP_DIVU)
`endif
`endif
`else
`else
                | (id_insn[3:0] == `OR1200_ALUOP_DIV)
                | (id_insn[3:0] == `OR1200_ALUOP_DIV)
                | (id_insn[3:0] == `OR1200_ALUOP_DIVU)
                | (id_insn[3:0] == `OR1200_ALUOP_DIVU)
                | (id_insn[3:0] == `OR1200_ALUOP_MUL)
                | (id_insn[3:0] == `OR1200_ALUOP_MUL)
`endif
`endif
 
 
`ifdef OR1200_IMPL_ADDC
`ifdef OR1200_IMPL_ADDC
`else
`else
                | (id_insn[3:0] == `OR1200_ALUOP_ADDC)
                | (id_insn[3:0] == `OR1200_ALUOP_ADDC)
`endif
`endif
 
 
 
`ifdef OR1200_IMPL_ALU_FFL1
 
`else
 
                | (id_insn[3:0] == `OR1200_ALUOP_FFL1)
 
`endif
 
 
`ifdef OR1200_IMPL_ALU_ROTATE
`ifdef OR1200_IMPL_ALU_ROTATE
`else
`else
                | ((id_insn[3:0] == `OR1200_ALUOP_SHROT) &
                | ((id_insn[3:0] == `OR1200_ALUOP_SHROT) &
                   (id_insn[7:6] == `OR1200_SHROTOP_ROR))
                   (id_insn[7:6] == `OR1200_SHROTOP_ROR))
`endif
`endif
 
 
`ifdef OR1200_IMPL_SUB
`ifdef OR1200_IMPL_SUB
`else
`else
                | (id_insn[3:0] == `OR1200_ALUOP_SUB)
                | (id_insn[3:0] == `OR1200_ALUOP_SUB)
`endif
`endif
                ;
                ;
 
 
                // Illegal and OR1200 unsupported instructions
                // Illegal and OR1200 unsupported instructions
        default:
        default:
                except_illegal <=  1'b1;
                except_illegal <=  1'b1;
 
 
        endcase
        endcase
        end // if (!ex_freeze)
        end // if (!ex_freeze)
end
end
 
 
 
 
//
//
// Decode of alu_op
// Decode of alu_op
//
//
always @(posedge clk or `OR1200_RST_EVENT rst) begin
always @(posedge clk or `OR1200_RST_EVENT rst) begin
        if (rst == `OR1200_RST_VALUE)
        if (rst == `OR1200_RST_VALUE)
                alu_op <=  `OR1200_ALUOP_NOP;
                alu_op <=  `OR1200_ALUOP_NOP;
        else if (!ex_freeze & id_freeze | ex_flushpipe)
        else if (!ex_freeze & id_freeze | ex_flushpipe)
                alu_op <=  `OR1200_ALUOP_NOP;
                alu_op <=  `OR1200_ALUOP_NOP;
        else if (!ex_freeze) begin
        else if (!ex_freeze) begin
          case (id_insn[31:26])         // synopsys parallel_case
          case (id_insn[31:26])         // synopsys parallel_case
 
 
            // l.movhi
            // l.movhi
            `OR1200_OR32_MOVHI:
            `OR1200_OR32_MOVHI:
              alu_op <=  `OR1200_ALUOP_MOVHI;
              alu_op <=  `OR1200_ALUOP_MOVHI;
 
 
            // l.addi
            // l.addi
            `OR1200_OR32_ADDI:
            `OR1200_OR32_ADDI:
              alu_op <=  `OR1200_ALUOP_ADD;
              alu_op <=  `OR1200_ALUOP_ADD;
 
 
            // l.addic
            // l.addic
            `OR1200_OR32_ADDIC:
            `OR1200_OR32_ADDIC:
              alu_op <=  `OR1200_ALUOP_ADDC;
              alu_op <=  `OR1200_ALUOP_ADDC;
 
 
            // l.andi
            // l.andi
            `OR1200_OR32_ANDI:
            `OR1200_OR32_ANDI:
              alu_op <=  `OR1200_ALUOP_AND;
              alu_op <=  `OR1200_ALUOP_AND;
 
 
            // l.ori
            // l.ori
            `OR1200_OR32_ORI:
            `OR1200_OR32_ORI:
              alu_op <=  `OR1200_ALUOP_OR;
              alu_op <=  `OR1200_ALUOP_OR;
 
 
            // l.xori
            // l.xori
            `OR1200_OR32_XORI:
            `OR1200_OR32_XORI:
              alu_op <=  `OR1200_ALUOP_XOR;
              alu_op <=  `OR1200_ALUOP_XOR;
 
 
            // l.muli
            // l.muli
`ifdef OR1200_MULT_IMPLEMENTED
`ifdef OR1200_MULT_IMPLEMENTED
            `OR1200_OR32_MULI:
            `OR1200_OR32_MULI:
              alu_op <=  `OR1200_ALUOP_MUL;
              alu_op <=  `OR1200_ALUOP_MUL;
`endif
`endif
 
 
            // Shift and rotate insns with immediate
            // Shift and rotate insns with immediate
            `OR1200_OR32_SH_ROTI:
            `OR1200_OR32_SH_ROTI:
              alu_op <=  `OR1200_ALUOP_SHROT;
              alu_op <=  `OR1200_ALUOP_SHROT;
 
 
            // SFXX insns with immediate
            // SFXX insns with immediate
            `OR1200_OR32_SFXXI:
            `OR1200_OR32_SFXXI:
              alu_op <=  `OR1200_ALUOP_COMP;
              alu_op <=  `OR1200_ALUOP_COMP;
 
 
            // ALU instructions except the one with immediate
            // ALU instructions except the one with immediate
            `OR1200_OR32_ALU:
            `OR1200_OR32_ALU:
              alu_op <=  id_insn[3:0];
              alu_op <=  id_insn[3:0];
 
 
            // SFXX instructions
            // SFXX instructions
            `OR1200_OR32_SFXX:
            `OR1200_OR32_SFXX:
              alu_op <=  `OR1200_ALUOP_COMP;
              alu_op <=  `OR1200_ALUOP_COMP;
 
 
`ifdef OR1200_OR32_CUST5
`ifdef OR1200_OR32_CUST5
            // l.cust5 instructions
            // l.cust5 instructions
            `OR1200_OR32_CUST5:
            `OR1200_OR32_CUST5:
              alu_op <=  `OR1200_ALUOP_CUST5;
              alu_op <=  `OR1200_ALUOP_CUST5;
`endif
`endif
 
 
            // Default
            // Default
            default: begin
            default: begin
              alu_op <=  `OR1200_ALUOP_NOP;
              alu_op <=  `OR1200_ALUOP_NOP;
            end
            end
 
 
          endcase
          endcase
 
 
        end
        end
end
end
 
 
 
 
 
//
 
// Decode of alu_op2 (field of bits 9:8)
 
//
 
always @(posedge clk or `OR1200_RST_EVENT rst) begin
 
        if (rst == `OR1200_RST_VALUE)
 
                alu_op2 <=  0;
 
        else if (!ex_freeze & id_freeze | ex_flushpipe)
 
                alu_op2 <= 0;
 
        else if (!ex_freeze) begin
 
                alu_op2 <=  id_insn[`OR1200_ALUOP2_POS];
 
        end
 
end
 
 
 
 
//
//
// Decode of spr_read, spr_write
// Decode of spr_read, spr_write
//
//
always @(posedge clk or `OR1200_RST_EVENT rst) begin
always @(posedge clk or `OR1200_RST_EVENT rst) begin
        if (rst == `OR1200_RST_VALUE) begin
        if (rst == `OR1200_RST_VALUE) begin
                spr_read <=  1'b0;
                spr_read <=  1'b0;
                spr_write <=  1'b0;
                spr_write <=  1'b0;
        end
        end
        else if (!ex_freeze & id_freeze | ex_flushpipe) begin
        else if (!ex_freeze & id_freeze | ex_flushpipe) begin
                spr_read <=  1'b0;
                spr_read <=  1'b0;
                spr_write <=  1'b0;
                spr_write <=  1'b0;
        end
        end
        else if (!ex_freeze) begin
        else if (!ex_freeze) begin
                case (id_insn[31:26])     // synopsys parallel_case
                case (id_insn[31:26])     // synopsys parallel_case
 
 
                // l.mfspr
                // l.mfspr
                `OR1200_OR32_MFSPR: begin
                `OR1200_OR32_MFSPR: begin
                        spr_read <=  1'b1;
                        spr_read <=  1'b1;
                        spr_write <=  1'b0;
                        spr_write <=  1'b0;
                end
                end
 
 
                // l.mtspr
                // l.mtspr
                `OR1200_OR32_MTSPR: begin
                `OR1200_OR32_MTSPR: begin
                        spr_read <=  1'b0;
                        spr_read <=  1'b0;
                        spr_write <=  1'b1;
                        spr_write <=  1'b1;
                end
                end
 
 
                // Default
                // Default
                default: begin
                default: begin
                        spr_read <=  1'b0;
                        spr_read <=  1'b0;
                        spr_write <=  1'b0;
                        spr_write <=  1'b0;
                end
                end
 
 
                endcase
                endcase
        end
        end
end
end
 
 
//
//
// Decode of mac_op
// Decode of mac_op
//
//
`ifdef OR1200_MAC_IMPLEMENTED
`ifdef OR1200_MAC_IMPLEMENTED
always @(id_insn) begin
always @(id_insn) begin
        case (id_insn[31:26])           // synopsys parallel_case
        case (id_insn[31:26])           // synopsys parallel_case
 
 
        // l.maci
        // l.maci
        `OR1200_OR32_MACI:
        `OR1200_OR32_MACI:
                id_mac_op =  `OR1200_MACOP_MAC;
                id_mac_op =  `OR1200_MACOP_MAC;
 
 
        // l.mac, l.msb
        // l.mac, l.msb
        `OR1200_OR32_MACMSB:
        `OR1200_OR32_MACMSB:
                id_mac_op =  id_insn[2:0];
                id_mac_op =  id_insn[2:0];
 
 
        // Illegal and OR1200 unsupported instructions
        // Illegal and OR1200 unsupported instructions
        default:
        default:
                id_mac_op =  `OR1200_MACOP_NOP;
                id_mac_op =  `OR1200_MACOP_NOP;
 
 
        endcase
        endcase
end
end
 
 
always @(posedge clk or `OR1200_RST_EVENT rst) begin
always @(posedge clk or `OR1200_RST_EVENT rst) begin
        if (rst == `OR1200_RST_VALUE)
        if (rst == `OR1200_RST_VALUE)
                ex_mac_op <=  `OR1200_MACOP_NOP;
                ex_mac_op <=  `OR1200_MACOP_NOP;
        else if (!ex_freeze & id_freeze | ex_flushpipe)
        else if (!ex_freeze & id_freeze | ex_flushpipe)
                ex_mac_op <=  `OR1200_MACOP_NOP;
                ex_mac_op <=  `OR1200_MACOP_NOP;
        else if (!ex_freeze)
        else if (!ex_freeze)
                ex_mac_op <=  id_mac_op;
                ex_mac_op <=  id_mac_op;
end
end
 
 
assign mac_op = abort_mvspr ? `OR1200_MACOP_NOP : ex_mac_op;
assign mac_op = abort_mvspr ? `OR1200_MACOP_NOP : ex_mac_op;
`else
`else
assign id_mac_op = `OR1200_MACOP_NOP;
assign id_mac_op = `OR1200_MACOP_NOP;
assign mac_op = `OR1200_MACOP_NOP;
assign mac_op = `OR1200_MACOP_NOP;
`endif
`endif
 
 
//
//
// Decode of shrot_op
// Decode of shrot_op
//
//
always @(posedge clk or `OR1200_RST_EVENT rst) begin
always @(posedge clk or `OR1200_RST_EVENT rst) begin
        if (rst == `OR1200_RST_VALUE)
        if (rst == `OR1200_RST_VALUE)
                shrot_op <=  `OR1200_SHROTOP_NOP;
                shrot_op <=  `OR1200_SHROTOP_NOP;
        else if (!ex_freeze & id_freeze | ex_flushpipe)
        else if (!ex_freeze & id_freeze | ex_flushpipe)
                shrot_op <=  `OR1200_SHROTOP_NOP;
                shrot_op <=  `OR1200_SHROTOP_NOP;
        else if (!ex_freeze) begin
        else if (!ex_freeze) begin
                shrot_op <=  id_insn[`OR1200_SHROTOP_POS];
                shrot_op <=  id_insn[`OR1200_SHROTOP_POS];
        end
        end
end
end
 
 
//
//
// Decode of rfwb_op
// Decode of rfwb_op
//
//
always @(posedge clk or `OR1200_RST_EVENT rst) begin
always @(posedge clk or `OR1200_RST_EVENT rst) begin
        if (rst == `OR1200_RST_VALUE)
        if (rst == `OR1200_RST_VALUE)
                rfwb_op <=  `OR1200_RFWBOP_NOP;
                rfwb_op <=  `OR1200_RFWBOP_NOP;
        else  if (!ex_freeze & id_freeze | ex_flushpipe)
        else  if (!ex_freeze & id_freeze | ex_flushpipe)
                rfwb_op <=  `OR1200_RFWBOP_NOP;
                rfwb_op <=  `OR1200_RFWBOP_NOP;
        else  if (!ex_freeze) begin
        else  if (!ex_freeze) begin
                case (id_insn[31:26])           // synopsys parallel_case
                case (id_insn[31:26])           // synopsys parallel_case
 
 
                // j.jal
                // j.jal
                `OR1200_OR32_JAL:
                `OR1200_OR32_JAL:
                        rfwb_op <=  {`OR1200_RFWBOP_LR, 1'b1};
                        rfwb_op <=  {`OR1200_RFWBOP_LR, 1'b1};
 
 
                // j.jalr
                // j.jalr
                `OR1200_OR32_JALR:
                `OR1200_OR32_JALR:
                        rfwb_op <=  {`OR1200_RFWBOP_LR, 1'b1};
                        rfwb_op <=  {`OR1200_RFWBOP_LR, 1'b1};
 
 
                // l.movhi
                // l.movhi
                `OR1200_OR32_MOVHI:
                `OR1200_OR32_MOVHI:
                        rfwb_op <=  {`OR1200_RFWBOP_ALU, 1'b1};
                        rfwb_op <=  {`OR1200_RFWBOP_ALU, 1'b1};
 
 
                // l.mfspr
                // l.mfspr
                `OR1200_OR32_MFSPR:
                `OR1200_OR32_MFSPR:
                        rfwb_op <=  {`OR1200_RFWBOP_SPRS, 1'b1};
                        rfwb_op <=  {`OR1200_RFWBOP_SPRS, 1'b1};
 
 
                // l.lwz
                // l.lwz
                `OR1200_OR32_LWZ:
                `OR1200_OR32_LWZ:
                        rfwb_op <=  {`OR1200_RFWBOP_LSU, 1'b1};
                        rfwb_op <=  {`OR1200_RFWBOP_LSU, 1'b1};
 
 
                // l.lbz
                // l.lbz
                `OR1200_OR32_LBZ:
                `OR1200_OR32_LBZ:
                        rfwb_op <=  {`OR1200_RFWBOP_LSU, 1'b1};
                        rfwb_op <=  {`OR1200_RFWBOP_LSU, 1'b1};
 
 
                // l.lbs
                // l.lbs
                `OR1200_OR32_LBS:
                `OR1200_OR32_LBS:
                        rfwb_op <=  {`OR1200_RFWBOP_LSU, 1'b1};
                        rfwb_op <=  {`OR1200_RFWBOP_LSU, 1'b1};
 
 
                // l.lhz
                // l.lhz
                `OR1200_OR32_LHZ:
                `OR1200_OR32_LHZ:
                        rfwb_op <=  {`OR1200_RFWBOP_LSU, 1'b1};
                        rfwb_op <=  {`OR1200_RFWBOP_LSU, 1'b1};
 
 
                // l.lhs
                // l.lhs
                `OR1200_OR32_LHS:
                `OR1200_OR32_LHS:
                        rfwb_op <=  {`OR1200_RFWBOP_LSU, 1'b1};
                        rfwb_op <=  {`OR1200_RFWBOP_LSU, 1'b1};
 
 
                // l.addi
                // l.addi
                `OR1200_OR32_ADDI:
                `OR1200_OR32_ADDI:
                        rfwb_op <=  {`OR1200_RFWBOP_ALU, 1'b1};
                        rfwb_op <=  {`OR1200_RFWBOP_ALU, 1'b1};
 
 
                // l.addic
                // l.addic
                `OR1200_OR32_ADDIC:
                `OR1200_OR32_ADDIC:
                        rfwb_op <=  {`OR1200_RFWBOP_ALU, 1'b1};
                        rfwb_op <=  {`OR1200_RFWBOP_ALU, 1'b1};
 
 
                // l.andi
                // l.andi
                `OR1200_OR32_ANDI:
                `OR1200_OR32_ANDI:
                        rfwb_op <=  {`OR1200_RFWBOP_ALU, 1'b1};
                        rfwb_op <=  {`OR1200_RFWBOP_ALU, 1'b1};
 
 
                // l.ori
                // l.ori
                `OR1200_OR32_ORI:
                `OR1200_OR32_ORI:
                        rfwb_op <=  {`OR1200_RFWBOP_ALU, 1'b1};
                        rfwb_op <=  {`OR1200_RFWBOP_ALU, 1'b1};
 
 
                // l.xori
                // l.xori
                `OR1200_OR32_XORI:
                `OR1200_OR32_XORI:
                        rfwb_op <=  {`OR1200_RFWBOP_ALU, 1'b1};
                        rfwb_op <=  {`OR1200_RFWBOP_ALU, 1'b1};
 
 
                // l.muli
                // l.muli
`ifdef OR1200_MULT_IMPLEMENTED
`ifdef OR1200_MULT_IMPLEMENTED
                `OR1200_OR32_MULI:
                `OR1200_OR32_MULI:
                        rfwb_op <=  {`OR1200_RFWBOP_ALU, 1'b1};
                        rfwb_op <=  {`OR1200_RFWBOP_ALU, 1'b1};
`endif
`endif
 
 
                // Shift and rotate insns with immediate
                // Shift and rotate insns with immediate
                `OR1200_OR32_SH_ROTI:
                `OR1200_OR32_SH_ROTI:
                        rfwb_op <=  {`OR1200_RFWBOP_ALU, 1'b1};
                        rfwb_op <=  {`OR1200_RFWBOP_ALU, 1'b1};
 
 
                // ALU instructions except the one with immediate
                // ALU instructions except the one with immediate
                `OR1200_OR32_ALU:
                `OR1200_OR32_ALU:
                        rfwb_op <=  {`OR1200_RFWBOP_ALU, 1'b1};
                        rfwb_op <=  {`OR1200_RFWBOP_ALU, 1'b1};
 
 
`ifdef OR1200_OR32_CUST5
`ifdef OR1200_OR32_CUST5
                // l.cust5 instructions
                // l.cust5 instructions
                `OR1200_OR32_CUST5:
                `OR1200_OR32_CUST5:
                        rfwb_op <=  {`OR1200_RFWBOP_ALU, 1'b1};
                        rfwb_op <=  {`OR1200_RFWBOP_ALU, 1'b1};
`endif
`endif
`ifdef OR1200_FPU_IMPLEMENTED
`ifdef OR1200_FPU_IMPLEMENTED
                  // FPU instructions, lf.XXX.s, except sfxx
                  // FPU instructions, lf.XXX.s, except sfxx
                  `OR1200_OR32_FLOAT:
                  `OR1200_OR32_FLOAT:
                    rfwb_op <=  {`OR1200_RFWBOP_FPU,!id_insn[3]};
                    rfwb_op <=  {`OR1200_RFWBOP_FPU,!id_insn[3]};
`endif
`endif
                // Instructions w/o register-file write-back
                // Instructions w/o register-file write-back
                default:
                default:
                        rfwb_op <=  `OR1200_RFWBOP_NOP;
                        rfwb_op <=  `OR1200_RFWBOP_NOP;
 
 
 
 
                endcase
                endcase
        end
        end
end
end
 
 
//
//
// Decode of id_branch_op
// Decode of id_branch_op
//
//
always @(posedge clk or `OR1200_RST_EVENT rst) begin
always @(posedge clk or `OR1200_RST_EVENT rst) begin
        if (rst == `OR1200_RST_VALUE)
        if (rst == `OR1200_RST_VALUE)
                id_branch_op <=  `OR1200_BRANCHOP_NOP;
                id_branch_op <=  `OR1200_BRANCHOP_NOP;
        else if (id_flushpipe)
        else if (id_flushpipe)
                id_branch_op <=  `OR1200_BRANCHOP_NOP;
                id_branch_op <=  `OR1200_BRANCHOP_NOP;
        else if (!id_freeze) begin
        else if (!id_freeze) begin
                case (if_insn[31:26])           // synopsys parallel_case
                case (if_insn[31:26])           // synopsys parallel_case
 
 
                // l.j
                // l.j
                `OR1200_OR32_J:
                `OR1200_OR32_J:
                        id_branch_op <=  `OR1200_BRANCHOP_J;
                        id_branch_op <=  `OR1200_BRANCHOP_J;
 
 
                // j.jal
                // j.jal
                `OR1200_OR32_JAL:
                `OR1200_OR32_JAL:
                        id_branch_op <=  `OR1200_BRANCHOP_J;
                        id_branch_op <=  `OR1200_BRANCHOP_J;
 
 
                // j.jalr
                // j.jalr
                `OR1200_OR32_JALR:
                `OR1200_OR32_JALR:
                        id_branch_op <=  `OR1200_BRANCHOP_JR;
                        id_branch_op <=  `OR1200_BRANCHOP_JR;
 
 
                // l.jr
                // l.jr
                `OR1200_OR32_JR:
                `OR1200_OR32_JR:
                        id_branch_op <=  `OR1200_BRANCHOP_JR;
                        id_branch_op <=  `OR1200_BRANCHOP_JR;
 
 
                // l.bnf
                // l.bnf
                `OR1200_OR32_BNF:
                `OR1200_OR32_BNF:
                        id_branch_op <=  `OR1200_BRANCHOP_BNF;
                        id_branch_op <=  `OR1200_BRANCHOP_BNF;
 
 
                // l.bf
                // l.bf
                `OR1200_OR32_BF:
                `OR1200_OR32_BF:
                        id_branch_op <=  `OR1200_BRANCHOP_BF;
                        id_branch_op <=  `OR1200_BRANCHOP_BF;
 
 
                // l.rfe
                // l.rfe
                `OR1200_OR32_RFE:
                `OR1200_OR32_RFE:
                        id_branch_op <=  `OR1200_BRANCHOP_RFE;
                        id_branch_op <=  `OR1200_BRANCHOP_RFE;
 
 
                // Non branch instructions
                // Non branch instructions
                default:
                default:
                        id_branch_op <=  `OR1200_BRANCHOP_NOP;
                        id_branch_op <=  `OR1200_BRANCHOP_NOP;
 
 
                endcase
                endcase
        end
        end
end
end
 
 
//
//
// Generation of ex_branch_op
// Generation of ex_branch_op
//
//
always @(posedge clk or `OR1200_RST_EVENT rst)
always @(posedge clk or `OR1200_RST_EVENT rst)
        if (rst == `OR1200_RST_VALUE)
        if (rst == `OR1200_RST_VALUE)
                ex_branch_op <=  `OR1200_BRANCHOP_NOP;
                ex_branch_op <=  `OR1200_BRANCHOP_NOP;
        else if (!ex_freeze & id_freeze | ex_flushpipe)
        else if (!ex_freeze & id_freeze | ex_flushpipe)
                ex_branch_op <=  `OR1200_BRANCHOP_NOP;
                ex_branch_op <=  `OR1200_BRANCHOP_NOP;
        else if (!ex_freeze)
        else if (!ex_freeze)
                ex_branch_op <=  id_branch_op;
                ex_branch_op <=  id_branch_op;
 
 
//
//
// Decode of id_lsu_op
// Decode of id_lsu_op
//
//
always @(id_insn) begin
always @(id_insn) begin
        case (id_insn[31:26])           // synopsys parallel_case
        case (id_insn[31:26])           // synopsys parallel_case
 
 
        // l.lwz
        // l.lwz
        `OR1200_OR32_LWZ:
        `OR1200_OR32_LWZ:
                id_lsu_op =  `OR1200_LSUOP_LWZ;
                id_lsu_op =  `OR1200_LSUOP_LWZ;
 
 
        // l.lbz
        // l.lbz
        `OR1200_OR32_LBZ:
        `OR1200_OR32_LBZ:
                id_lsu_op =  `OR1200_LSUOP_LBZ;
                id_lsu_op =  `OR1200_LSUOP_LBZ;
 
 
        // l.lbs
        // l.lbs
        `OR1200_OR32_LBS:
        `OR1200_OR32_LBS:
                id_lsu_op =  `OR1200_LSUOP_LBS;
                id_lsu_op =  `OR1200_LSUOP_LBS;
 
 
        // l.lhz
        // l.lhz
        `OR1200_OR32_LHZ:
        `OR1200_OR32_LHZ:
                id_lsu_op =  `OR1200_LSUOP_LHZ;
                id_lsu_op =  `OR1200_LSUOP_LHZ;
 
 
        // l.lhs
        // l.lhs
        `OR1200_OR32_LHS:
        `OR1200_OR32_LHS:
                id_lsu_op =  `OR1200_LSUOP_LHS;
                id_lsu_op =  `OR1200_LSUOP_LHS;
 
 
        // l.sw
        // l.sw
        `OR1200_OR32_SW:
        `OR1200_OR32_SW:
                id_lsu_op =  `OR1200_LSUOP_SW;
                id_lsu_op =  `OR1200_LSUOP_SW;
 
 
        // l.sb
        // l.sb
        `OR1200_OR32_SB:
        `OR1200_OR32_SB:
                id_lsu_op =  `OR1200_LSUOP_SB;
                id_lsu_op =  `OR1200_LSUOP_SB;
 
 
        // l.sh
        // l.sh
        `OR1200_OR32_SH:
        `OR1200_OR32_SH:
                id_lsu_op =  `OR1200_LSUOP_SH;
                id_lsu_op =  `OR1200_LSUOP_SH;
 
 
        // Non load/store instructions
        // Non load/store instructions
        default:
        default:
                id_lsu_op =  `OR1200_LSUOP_NOP;
                id_lsu_op =  `OR1200_LSUOP_NOP;
 
 
        endcase
        endcase
end
end
 
 
//
//
// Decode of comp_op
// Decode of comp_op
//
//
always @(posedge clk or `OR1200_RST_EVENT rst) begin
always @(posedge clk or `OR1200_RST_EVENT rst) begin
        if (rst == `OR1200_RST_VALUE) begin
        if (rst == `OR1200_RST_VALUE) begin
                comp_op <=  4'd0;
                comp_op <=  4'd0;
        end else if (!ex_freeze & id_freeze | ex_flushpipe)
        end else if (!ex_freeze & id_freeze | ex_flushpipe)
                comp_op <=  4'd0;
                comp_op <=  4'd0;
        else if (!ex_freeze)
        else if (!ex_freeze)
                comp_op <=  id_insn[24:21];
                comp_op <=  id_insn[24:21];
end
end
 
 
`ifdef OR1200_FPU_IMPLEMENTED
`ifdef OR1200_FPU_IMPLEMENTED
//
//
// Decode of FPU ops
// Decode of FPU ops
//
//
   assign fpu_op = {(id_insn[31:26] == `OR1200_OR32_FLOAT),
   assign fpu_op = {(id_insn[31:26] == `OR1200_OR32_FLOAT),
                    id_insn[`OR1200_FPUOP_WIDTH-2:0]};
                    id_insn[`OR1200_FPUOP_WIDTH-2:0]};
`else
`else
   assign fpu_op = {`OR1200_FPUOP_WIDTH{1'b0}};
   assign fpu_op = {`OR1200_FPUOP_WIDTH{1'b0}};
`endif
`endif
 
 
 
 
//
//
// Decode of l.sys
// Decode of l.sys
//
//
always @(posedge clk or `OR1200_RST_EVENT rst) begin
always @(posedge clk or `OR1200_RST_EVENT rst) begin
        if (rst == `OR1200_RST_VALUE)
        if (rst == `OR1200_RST_VALUE)
                sig_syscall <=  1'b0;
                sig_syscall <=  1'b0;
        else if (!ex_freeze & id_freeze | ex_flushpipe)
        else if (!ex_freeze & id_freeze | ex_flushpipe)
                sig_syscall <=  1'b0;
                sig_syscall <=  1'b0;
        else if (!ex_freeze) begin
        else if (!ex_freeze) begin
`ifdef OR1200_VERBOSE
`ifdef OR1200_VERBOSE
// synopsys translate_off
// synopsys translate_off
                if (id_insn[31:23] == {`OR1200_OR32_XSYNC, 3'b000})
                if (id_insn[31:23] == {`OR1200_OR32_XSYNC, 3'b000})
                        $display("Generating sig_syscall");
                        $display("Generating sig_syscall");
// synopsys translate_on
// synopsys translate_on
`endif
`endif
                sig_syscall <=  (id_insn[31:23] == {`OR1200_OR32_XSYNC, 3'b000});
                sig_syscall <=  (id_insn[31:23] == {`OR1200_OR32_XSYNC, 3'b000});
        end
        end
end
end
 
 
//
//
// Decode of l.trap
// Decode of l.trap
//
//
always @(posedge clk or `OR1200_RST_EVENT rst) begin
always @(posedge clk or `OR1200_RST_EVENT rst) begin
        if (rst == `OR1200_RST_VALUE)
        if (rst == `OR1200_RST_VALUE)
                sig_trap <=  1'b0;
                sig_trap <=  1'b0;
        else if (!ex_freeze & id_freeze | ex_flushpipe)
        else if (!ex_freeze & id_freeze | ex_flushpipe)
                sig_trap <=  1'b0;
                sig_trap <=  1'b0;
        else if (!ex_freeze) begin
        else if (!ex_freeze) begin
`ifdef OR1200_VERBOSE
`ifdef OR1200_VERBOSE
// synopsys translate_off
// synopsys translate_off
                if (id_insn[31:23] == {`OR1200_OR32_XSYNC, 3'b010})
                if (id_insn[31:23] == {`OR1200_OR32_XSYNC, 3'b010})
                        $display("Generating sig_trap");
                        $display("Generating sig_trap");
// synopsys translate_on
// synopsys translate_on
`endif
`endif
                sig_trap <=  (id_insn[31:23] == {`OR1200_OR32_XSYNC, 3'b010})
                sig_trap <=  (id_insn[31:23] == {`OR1200_OR32_XSYNC, 3'b010})
                        | du_hwbkpt;
                        | du_hwbkpt;
        end
        end
end
end
 
 
// Decode destination register address for data cache to check if store ops
// Decode destination register address for data cache to check if store ops
// are being done from the stack register (r1) or frame pointer register (r2)
// are being done from the stack register (r1) or frame pointer register (r2)
`ifdef OR1200_DC_NOSTACKWRITETHROUGH
`ifdef OR1200_DC_NOSTACKWRITETHROUGH
always @(posedge clk or `OR1200_RST_EVENT rst) begin
always @(posedge clk or `OR1200_RST_EVENT rst) begin
   if (rst == `OR1200_RST_VALUE)
   if (rst == `OR1200_RST_VALUE)
     dc_no_writethrough <= 0;
     dc_no_writethrough <= 0;
   else if (!ex_freeze)
   else if (!ex_freeze)
     dc_no_writethrough <= (id_insn[20:16] == 5'd1) | (id_insn[20:16] == 5'd2);
     dc_no_writethrough <= (id_insn[20:16] == 5'd1) | (id_insn[20:16] == 5'd2);
end
end
`else
`else
 
 
   assign dc_no_writethrough = 0;
   assign dc_no_writethrough = 0;
 
 
`endif
`endif
 
 
endmodule
endmodule
 
 

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