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/////////////////////////////////////////////////////////////////////

////                                                             ////

////  Author: Eyal Hochberg                                      ////

////          eyal@provartec.com                                 ////

////                                                             ////

////  Downloaded from: http://www.opencores.org                  ////

/////////////////////////////////////////////////////////////////////

////                                                             ////

//// Copyright (C) 2010 Provartec LTD                            ////

//// www.provartec.com                                           ////

//// info@provartec.com                                          ////

////                                                             ////

//// This source file may be used and distributed without        ////

//// restriction provided that this copyright statement is not   ////

//// removed from the file and that any derivative work contains ////

//// the original copyright notice and the associated disclaimer.////

////                                                             ////

//// This source file is free software; you can redistribute it  ////

//// and/or modify it under the terms of the GNU Lesser General  ////

//// Public License as published by the Free Software Foundation.////

////                                                             ////

//// This source 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 Lesser General Public License for more////

//// details. http://www.gnu.org/licenses/lgpl.html              ////

////                                                             ////

/////////////////////////////////////////////////////////////////////

//---------------------------------------------------------

//-- File generated by RobustVerilog parser

//-- Version: 1.0

//-- Invoked Fri Mar 25 23:31:22 2011

//--

//-- Source file: prgen_joint_stall.v

//---------------------------------------------------------

module prgen_joint_stall(clk,reset,joint_req_out,rd_transfer,rd_transfer_size,ch_fifo_rd,data_fullness_pre,HOLD,joint_fifo_rd_valid,rd_transfer_size_joint,rd_transfer_full,joint_stall);

   parameter                  SIZE_BITS   = 1;

   input               clk;

   input               reset;

   input               joint_req_out;

   input               rd_transfer;

   input [SIZE_BITS-1:0]      rd_transfer_size;

   input               ch_fifo_rd;

   input [2:0]               data_fullness_pre;

   input               HOLD;

   output               joint_fifo_rd_valid;

   output [SIZE_BITS-1:0]     rd_transfer_size_joint;

   output               rd_transfer_full;

   output               joint_stall;

   wire               rd_transfer_joint;

   wire               joint_fifo_rd;

   wire               joint_fifo_rd_valid;

   wire [2:0]               count_ch_fifo_pre;

   reg [2:0]               count_ch_fifo;

   wire               joint_stall_pre;

   reg                   joint_stall_reg;

   wire               joint_not_ready_pre;

   wire               joint_not_ready;

   wire [SIZE_BITS-1:0]       rd_transfer_size_joint;

   wire               rd_transfer_full;

   reg [2:0]               joint_rd_stall_num;

   wire               joint_rd_stall;

   assign               rd_transfer_joint   = joint_req_out & rd_transfer;

   prgen_delay #(2) delay_joint_fifo_rd (.clk(clk), .reset(reset), .din(rd_transfer_joint), .dout(joint_fifo_rd));

   assign               count_ch_fifo_pre   = count_ch_fifo + rd_transfer_joint - ch_fifo_rd;

   //count fullness of channel's fifo

   always @(posedge clk or posedge reset)

     if (reset)

       count_ch_fifo <= #1 3'd0;

     else if (joint_req_out & (rd_transfer_joint | ch_fifo_rd))

       count_ch_fifo <= #1 count_ch_fifo_pre;

   //prevent read channel to overflow the channel's fifo

   assign               joint_stall_pre     = joint_req_out & ((count_ch_fifo_pre > 'd2) | ((count_ch_fifo_pre == 'd2) & (data_fullness_pre > 'd1)) | HOLD);

   //prevent write channel to overflow the wr data fifo

   assign               joint_not_ready_pre = joint_req_out & (data_fullness_pre > 'd1) & (~(rd_transfer_joint & joint_stall_pre));

   always @(posedge clk or posedge reset)

     if (reset)

       joint_stall_reg <= #1 1'b0;

     else if (joint_stall_pre)

       joint_stall_reg <= #1 1'b1;

     else if (count_ch_fifo_pre == 'd0)

       joint_stall_reg <= #1 1'b0;

   assign               joint_stall = joint_stall_reg | (joint_req_out & HOLD);

   prgen_delay #(1) delay_joint_not_ready (.clk(clk), .reset(reset), .din(joint_not_ready_pre), .dout(joint_not_ready));

   prgen_fifo #(SIZE_BITS, 2)

   rd_transfer_fifo(

            .clk(clk),

            .reset(reset),

            .push(rd_transfer_joint),

            .pop(joint_fifo_rd_valid),

            .din(rd_transfer_size),

            .dout(rd_transfer_size_joint),

            .empty(),

            .full(rd_transfer_full)

            );

   prgen_stall #(3) stall_joint_fifo_rd (.clk(clk), .reset(reset), .din(joint_fifo_rd), .stall(joint_not_ready), .dout(joint_fifo_rd_valid));

endmodule