URL
https://opencores.org/ocsvn/mips789/mips789/trunk
Subversion Repositories mips789
[/] [mips789/] [branches/] [mcupro/] [verilog/] [mips_core/] [pc_gen.v] - Rev 51
Compare with Previous | Blame | View Log
///////////////////////////////////////////////////////////////////// //// Author: Liwei //// //// //// //// //// //// If you encountered any problem, please contact : //// //// Email: mcupro@yahoo.com.hk or mcupro@opencores.org //// //// //// //// Downloaded from: //// //// http://www.opencores.org/pdownloads.cgi/list/mips789 //// ///////////////////////////////////////////////////////////////////// //// //// //// Copyright (C) 2006-2007 Liwei //// //// mcupro@yahoo.com.hk //// //// //// //// //// //// This source file may be used and distributed freely without //// //// restriction provided that this copyright statement is not //// //// removed from the file and any derivative work contains the //// //// original copyright notice and the associated disclaimer. //// //// //// //// Please let the author know if it is used //// //// for commercial purpose. //// //// //// //// THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY //// //// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED //// //// TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS //// //// FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL THE AUTHOR //// //// OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, //// //// INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES //// //// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE //// //// GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR //// //// BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF //// //// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT //// //// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT //// //// OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE //// //// POSSIBILITY OF SUCH DAMAGE. //// //// //// ///////////////////////////////////////////////////////////////////// //// //// //// //// //// Date of Creation: 2007.8.1 //// //// //// //// Version: 0.0.1 //// //// //// //// Description: //// //// //// //// //// ///////////////////////////////////////////////////////////////////// //// //// //// Change log: //// //// //// ///////////////////////////////////////////////////////////////////// `define PC_IGN 1 `define PC_KEP 2 `define PC_IRQ 4 `define PC_RST 8 `define PC_J 1 `define PC_JR 2 `define PC_BC 4 `define PC_NEXT 5 `define PC_SPC 6 `define PC_RET 6 `define PC_NOP 0 module pc_gen2 ( input [2:0]ctl, output reg [31:0]pc_next, input [3:0] pc_prectl, input check, input [31:0]s, input [31:0]pc, input [31:0]zz_spc, input [31:0]imm, input [31:0]irq ); wire [32:0] br_addr = pc + imm ; always @ (*) if(pc_prectl == `PC_IGN ) begin case (ctl) `PC_RET : pc_next = zz_spc ; `PC_J:pc_next ={pc[31:28],imm[27:0]}; `PC_JR: pc_next = s; `PC_BC: pc_next = (check)?({br_addr[31:0]}):(pc+4); `PC_NEXT:pc_next = pc+ 4 ; default pc_next = pc + 4; endcase end else begin case (pc_prectl) `PC_KEP : pc_next=pc; `PC_IRQ : pc_next=irq; `PC_RST : pc_next='d0; default:pc_next =0; endcase end endmodule