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//////////////////////////////////////////////////////////////////////
////                                                              ////
//// Copyright (C) 2009 Authors and OPENCORES.ORG                 ////
////                                                              ////
//// 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; ////
//// either version 2.1 of the License, or (at your option) any   ////
//// later version.                                               ////
////                                                              ////
//// 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.                                                     ////
////                                                              ////
//// You should have received a copy of the GNU Lesser General    ////
//// Public License along with this source; if not, download it   ////
//// from http://www.opencores.org/lgpl.shtml                     ////
////                                                              ////
//////////////////////////////////////////////////////////////////////
 
//////////////////////////////////////////////////////////////////////
////                                                              ////
////  MESI_ISC Project                                            ////
////                                                              ////
////  Author(s):                                                  ////
////      - Yair Amitay       yair.amitay@yahoo.com               ////
////                          www.linkedin.com/in/yairamitay      ////
////                                                              ////
////  Description                                                 ////
////  mesi_isc_broad_cntl                                          ////
////  -------------------                                         ////
////                                                              ////
////                                                              ////
////  To Do:                                                      ////
////   -                                                          ////
////                                                              ////
//////////////////////////////////////////////////////////////////////
 
`include "mesi_isc_define.v"
 
module mesi_isc_broad_cntl
    (
     // Inputs
     clk,
     rst,
     cbus_ack_array_i,
     fifo_status_empty_i,
     fifo_status_full_i,
     broad_snoop_type_i,
     broad_snoop_cpu_id_i,
     broad_snoop_id_i,
     // Outputs
     cbus_cmd_array_o,
     broad_fifo_rd_o
     );
parameter
  CBUS_CMD_WIDTH           = 3,
  BROAD_TYPE_WIDTH         = 2,
  BROAD_ID_WIDTH           = 5;
 
// Inputs
//================================
// System
input                   clk;          // System clock
input                   rst;          // Active high system reset
// Coherence buses
input [3:0]             cbus_ack_array_i;
// broad_fifo
input                   fifo_status_empty_i;
input                   fifo_status_full_i;
// broad_fifo
input [BROAD_TYPE_WIDTH-1:0] broad_snoop_type_i; // The type of the broad
input [1:0]             broad_snoop_cpu_id_i; // The ID of the initiator CPU
input [BROAD_ID_WIDTH-1:0] broad_snoop_id_i; // The ID of the broad
 
// Outputs
//================================
output [4*CBUS_CMD_WIDTH-1:0] cbus_cmd_array_o; // Command for coherence bus.
                                      // write broadcast, read broadcast, write
                                      // enable or read enable 
// fifo
output                  broad_fifo_rd_o;
 
// Regs & wires
//================================
wire [CBUS_CMD_WIDTH-1:0] cbus_cmd3;  // Command for coherence bus.
wire [CBUS_CMD_WIDTH-1:0] cbus_cmd2;  // Command for coherence bus.
wire [CBUS_CMD_WIDTH-1:0] cbus_cmd1;  // Command for coherence bus.
wire [CBUS_CMD_WIDTH-1:0] cbus_cmd0;  // Command for coherence bus.
reg                       broadcast_in_progress; // A broadcast process
                                      // contains 2 stages. The first stage is 
                                      // to send read or write broadcast to
                                      // all CPUs and to receive an
                                      // acknowledge for each one. The second
                                      // stage is to send an
                                      // enable-access to the initiator CPU. 
reg  [3:0]                cbus_active_broad_array; // For each bit, when high a
                                      // broad access is sent to the CPU
reg  [3:0]                cbus_active_en_access_array; // For each bit, when
                                      // hing a enable-access is sent to the
                                      // CPU
reg                       broad_fifo_rd_o; // output
wire [3:0]                cbus_active_en_access_and_not_cbus_ack_array;
 
 
//cbus_cmd
assign cbus_cmd_array_o[(3+1)*CBUS_CMD_WIDTH-1 : 3*CBUS_CMD_WIDTH] = cbus_cmd3;
assign cbus_cmd_array_o[(2+1)*CBUS_CMD_WIDTH-1 : 2*CBUS_CMD_WIDTH] = cbus_cmd2;
assign cbus_cmd_array_o[(1+1)*CBUS_CMD_WIDTH-1 : 1*CBUS_CMD_WIDTH] = cbus_cmd1;
assign cbus_cmd_array_o[(0+1)*CBUS_CMD_WIDTH-1 : 0*CBUS_CMD_WIDTH] = cbus_cmd0;
 
// The command of the coherence bus is define according to the state of 
// cbus_active_broad_array and cbus_active_en_access_array
       //     \ /
assign cbus_cmd3 =
         // The broadcast proccess is active. Send the broadcast request 
         //                     \ /
         cbus_active_broad_array[3] ?
           broad_snoop_type_i == `MESI_ISC_BREQ_TYPE_WR ?
                                           `MESI_ISC_CBUS_CMD_WR_SNOOP:
                                           `MESI_ISC_CBUS_CMD_RD_SNOOP     :
         // All the broadcast proccesses were done. This CPU is the initiator
         // of the request. Enable it to continue by send en_wr/en_rd
         !(|cbus_active_broad_array)    &
         //                         \ /
         cbus_active_en_access_array[3] &
         ~broad_fifo_rd_o ?
           broad_snoop_type_i == `MESI_ISC_BREQ_TYPE_WR ?
                                           `MESI_ISC_CBUS_CMD_EN_WR:
                                           `MESI_ISC_CBUS_CMD_EN_RD        :
                                           `MESI_ISC_CBUS_CMD_NOP;
       //     \ /
assign cbus_cmd2 =
         //                     \ /
         cbus_active_broad_array[2] ?
           broad_snoop_type_i == `MESI_ISC_BREQ_TYPE_WR ?
                                           `MESI_ISC_CBUS_CMD_WR_SNOOP:
                                           `MESI_ISC_CBUS_CMD_RD_SNOOP     :
         !(|cbus_active_broad_array)    &
         //                         \ /
         cbus_active_en_access_array[2] &
         ~broad_fifo_rd_o ?
           broad_snoop_type_i == `MESI_ISC_BREQ_TYPE_WR ?
                                           `MESI_ISC_CBUS_CMD_EN_WR:
                                           `MESI_ISC_CBUS_CMD_EN_RD        :
                                           `MESI_ISC_CBUS_CMD_NOP;
       //     \ /
assign cbus_cmd1 =
         //                     \ /
         cbus_active_broad_array[1] ?
           broad_snoop_type_i == `MESI_ISC_BREQ_TYPE_WR ?
                                           `MESI_ISC_CBUS_CMD_WR_SNOOP:
                                           `MESI_ISC_CBUS_CMD_RD_SNOOP     :
         !(|cbus_active_broad_array)    &
         //                         \ /
         cbus_active_en_access_array[1] &
         ~broad_fifo_rd_o ?
           broad_snoop_type_i == `MESI_ISC_BREQ_TYPE_WR ?
                                           `MESI_ISC_CBUS_CMD_EN_WR:
                                           `MESI_ISC_CBUS_CMD_EN_RD        :
                                           `MESI_ISC_CBUS_CMD_NOP;
       //     \ /
assign cbus_cmd0 =
         // Send read or write broad according to the type of the broad.
         //                     \ /
         cbus_active_broad_array[0] ?
           broad_snoop_type_i == `MESI_ISC_BREQ_TYPE_WR ?
                                           `MESI_ISC_CBUS_CMD_WR_SNOOP:
                                           `MESI_ISC_CBUS_CMD_RD_SNOOP     :
         !(|cbus_active_broad_array)    &
         //                         \ /
         cbus_active_en_access_array[0] &
         ~broad_fifo_rd_o ?
           broad_snoop_type_i == `MESI_ISC_BREQ_TYPE_WR ?
                                           `MESI_ISC_CBUS_CMD_EN_WR:
                                           `MESI_ISC_CBUS_CMD_EN_RD        :
 
                                           `MESI_ISC_CBUS_CMD_NOP;
 
 
// A broadcast process contains 5 sub-processes: Each one of the 4 CPU receives
// a snoop request and answers with an acknowledge. Then the initiator CPU
// receives an access enable and answer  answers with an acknowledge.
//
// The broadcast process *stages* are:
// 1. Curently there is no an active process. If there is a valid broadcast to
//  send then:
// 1.1 broadcast_in_progress   <= 1 : It represents an active process of
//     broadcast. It contains 4 snoop sub-processes and 1 enable sub-process. 
// 1.2 cbus_active_broad_array <= 4'b1111 : Each bit represents an active
//     sub-process, for each CPU - sending a snoop request and get an answer
//     with an acknowledge.
// 1.3 cbus_active_en_access_array[ID of initiator CPU] <= 1
//     The corresponding bit of the initiator CPU in the
//     cbus_active_en_access_array is set to enable in stage 4 to send an
//     enable-access to the initiator CPU.
// 2. cbus_active_broad_array[ID of CPU] <= 0
//    A snoop request is send for all the CPUs. For each CPU that answers with
//    acknowledge the corresponding bit is clear:
//    cbus_active_broad_array == 0
//    After all CPUs answer with acknowledge all the bits of 
//    cbus_active_broad_array are clear.
// 3. cbus_active_en_access_array[ID of initiator CPU] <= 0
//    broadcast_in_progress                            <= 0
//    The enable access is sent to the initiator CPU. When it answers with an
//    acknowledge then the broadcast process is finished:  the corresponding
//    bit in the cbus_active_en_access_array is clear and
//    the broadcast_in_progress is clear
//
//
// broadcast_in_progress
// There is an active action of the broadcast. Either not all CPU received the
// broadcast and return acknowledge. or the initiator CPU received the access
// enable and return acknowledge. 
//
// cbus_active_broad_array
// For each bit, when set - there is an active process of sending a snoop
// request and answering with an acknowledge.
// 
// cbus_active_en_access_array
// For each bit, when set -  there is an active process of sending 
// enable-access request to the initiator CPU and receive an acknowledge answer.
// The enable-access request is send only after all CPUs receive and approve
// the snoop requests.
//
// broad_fifo_rd_o
// When broadcast process in finish clear the corresponding entry from the fifo
always @(posedge clk or posedge rst)
  if (rst)
  begin
        broadcast_in_progress       <= 0;
        cbus_active_broad_array     <= 4'b0000;
        cbus_active_en_access_array <= 4'b0000;
        broad_fifo_rd_o             <= 0;
  end
  else if (~broadcast_in_progress & ~broad_fifo_rd_o)
    if (~fifo_status_empty_i)
    // Stage 1
      begin
        broadcast_in_progress       <= 1;
        case (broad_snoop_cpu_id_i) // The initiator does not received a
                                    // broadcast for the same line it asks the
                                    // broadcast
          0:
          begin
            cbus_active_broad_array     <= 4'b1110;
            cbus_active_en_access_array <= 4'b0001;
          end
          1:
          begin
            cbus_active_broad_array     <= 4'b1101;
            cbus_active_en_access_array <= 4'b0010;
          end
          2:
          begin
            cbus_active_broad_array     <= 4'b1011;
            cbus_active_en_access_array <= 4'b0100;
          end
          3:
          begin
            cbus_active_broad_array     <= 4'b0111;
            cbus_active_en_access_array <= 4'b1000;
          end
          default
          begin
            cbus_active_broad_array     <= 4'b0000;
            cbus_active_en_access_array <= 4'b0000;
          end
        endcase
        broad_fifo_rd_o             <= 0;
      end
    else // if (~fifo_status_empty_i)
    begin
        broadcast_in_progress       <= 0;
        cbus_active_broad_array     <= 4'b0000;
        cbus_active_en_access_array <= 4'b0000;
        broad_fifo_rd_o             <= 0;
    end
  else // if (~broadcast_in_progress)
    // Stage 2
    if (|cbus_active_broad_array)     // There is at least on active snoop
                                      //  sub-process
      begin
        broadcast_in_progress       <= 1;
        // Clear related sub-process of a CPU then returns ack for the snoop
        // request.
        cbus_active_broad_array     <= cbus_active_broad_array &
                                       ~cbus_ack_array_i;
        cbus_active_en_access_array <= cbus_active_en_access_array;
        broad_fifo_rd_o             <= 0;
      end
    // Stage 3
    else if (broad_fifo_rd_o)         // All snoop sub-process were done
      begin
        broadcast_in_progress       <= 0;
        cbus_active_broad_array     <= 0;
        cbus_active_en_access_array <= 0;
        broad_fifo_rd_o             <= 0;
      end
    else
      broad_fifo_rd_o <= !(|(cbus_active_en_access_and_not_cbus_ack_array));
 
assign cbus_active_en_access_and_not_cbus_ack_array =
        cbus_active_en_access_array  & ~cbus_ack_array_i;
 
 
endmodule

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[/] [mesi_isc/] [trunk/] [src/] [rtl/] [mesi_isc_broad_cntl.v] - Blame information for rev 2

Line No.	Rev	Author	Line
1	2	yaira	`//////////////////////////////////////////////////////////////////////`
2			`//// ////`
3			`//// Copyright (C) 2009 Authors and OPENCORES.ORG ////`
4			`//// ////`
5			`//// This source file may be used and distributed without ////`
6			`//// restriction provided that this copyright statement is not ////`
7			`//// removed from the file and that any derivative work contains ////`
8			`//// the original copyright notice and the associated disclaimer. ////`
9			`//// ////`
10			`//// This source file is free software; you can redistribute it ////`
11			`//// and/or modify it under the terms of the GNU Lesser General ////`
12			`//// Public License as published by the Free Software Foundation; ////`
13			`//// either version 2.1 of the License, or (at your option) any ////`
14			`//// later version. ////`
15			`//// ////`
16			`//// This source is distributed in the hope that it will be ////`
17			`//// useful, but WITHOUT ANY WARRANTY; without even the implied ////`
18			`//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR ////`
19			`//// PURPOSE. See the GNU Lesser General Public License for more ////`
20			`//// details. ////`
21			`//// ////`
22			`//// You should have received a copy of the GNU Lesser General ////`
23			`//// Public License along with this source; if not, download it ////`
24			`//// from http://www.opencores.org/lgpl.shtml ////`
25			`//// ////`
26			`//////////////////////////////////////////////////////////////////////`
27
28			`//////////////////////////////////////////////////////////////////////`
29			`//// ////`
30			`//// MESI_ISC Project ////`
31			`//// ////`
32			`//// Author(s): ////`
33			`//// - Yair Amitay yair.amitay@yahoo.com ////`
34			`//// www.linkedin.com/in/yairamitay ////`
35			`//// ////`
36			`//// Description ////`
37			`//// mesi_isc_broad_cntl ////`
38			`//// ------------------- ////`
39			`//// ////`
40			`//// ////`
41			`//// To Do: ////`
42			`//// - ////`
43			`//// ////`
44			`//////////////////////////////////////////////////////////////////////`
45
46			`include "mesi_isc_define.v"
47
48			`module mesi_isc_broad_cntl`
49			`(`
50			`// Inputs`
51			`clk,`
52			`rst,`
53			`cbus_ack_array_i,`
54			`fifo_status_empty_i,`
55			`fifo_status_full_i,`
56			`broad_snoop_type_i,`
57			`broad_snoop_cpu_id_i,`
58			`broad_snoop_id_i,`
59			`// Outputs`
60			`cbus_cmd_array_o,`
61			`broad_fifo_rd_o`
62			`);`
63			`parameter`
64			`CBUS_CMD_WIDTH = 3,`
65			`BROAD_TYPE_WIDTH = 2,`
66			`BROAD_ID_WIDTH = 5;`
67
68			`// Inputs`
69			`//================================`
70			`// System`
71			`input clk; // System clock`
72			`input rst; // Active high system reset`
73			`// Coherence buses`
74			`input [3:0] cbus_ack_array_i;`
75			`// broad_fifo`
76			`input fifo_status_empty_i;`
77			`input fifo_status_full_i;`
78			`// broad_fifo`
79			`input [BROAD_TYPE_WIDTH-1:0] broad_snoop_type_i; // The type of the broad`
80			`input [1:0] broad_snoop_cpu_id_i; // The ID of the initiator CPU`
81			`input [BROAD_ID_WIDTH-1:0] broad_snoop_id_i; // The ID of the broad`
82
83			`// Outputs`
84			`//================================`
85			`output [4*CBUS_CMD_WIDTH-1:0] cbus_cmd_array_o; // Command for coherence bus.`
86			`// write broadcast, read broadcast, write`
87			`// enable or read enable`
88			`// fifo`
89			`output broad_fifo_rd_o;`
90
91			`// Regs & wires`
92			`//================================`
93			`wire [CBUS_CMD_WIDTH-1:0] cbus_cmd3; // Command for coherence bus.`
94			`wire [CBUS_CMD_WIDTH-1:0] cbus_cmd2; // Command for coherence bus.`
95			`wire [CBUS_CMD_WIDTH-1:0] cbus_cmd1; // Command for coherence bus.`
96			`wire [CBUS_CMD_WIDTH-1:0] cbus_cmd0; // Command for coherence bus.`
97			`reg broadcast_in_progress; // A broadcast process`
98			`// contains 2 stages. The first stage is`
99			`// to send read or write broadcast to`
100			`// all CPUs and to receive an`
101			`// acknowledge for each one. The second`
102			`// stage is to send an`
103			`// enable-access to the initiator CPU.`
104			`reg [3:0] cbus_active_broad_array; // For each bit, when high a`
105			`// broad access is sent to the CPU`
106			`reg [3:0] cbus_active_en_access_array; // For each bit, when`
107			`// hing a enable-access is sent to the`
108			`// CPU`
109			`reg broad_fifo_rd_o; // output`
110			`wire [3:0] cbus_active_en_access_and_not_cbus_ack_array;`
111
112
113			`//cbus_cmd`
114			`assign cbus_cmd_array_o[(3+1)CBUS_CMD_WIDTH-1 : 3CBUS_CMD_WIDTH] = cbus_cmd3;`
115			`assign cbus_cmd_array_o[(2+1)CBUS_CMD_WIDTH-1 : 2CBUS_CMD_WIDTH] = cbus_cmd2;`
116			`assign cbus_cmd_array_o[(1+1)CBUS_CMD_WIDTH-1 : 1CBUS_CMD_WIDTH] = cbus_cmd1;`
117			`assign cbus_cmd_array_o[(0+1)CBUS_CMD_WIDTH-1 : 0CBUS_CMD_WIDTH] = cbus_cmd0;`
118
119			`// The command of the coherence bus is define according to the state of`
120			`// cbus_active_broad_array and cbus_active_en_access_array`
121			`// \ /`
122			`assign cbus_cmd3 =`
123			`// The broadcast proccess is active. Send the broadcast request`
124			`// \ /`
125			`cbus_active_broad_array[3] ?`
126			broad_snoop_type_i == `MESI_ISC_BREQ_TYPE_WR ?
127			`MESI_ISC_CBUS_CMD_WR_SNOOP:
128			`MESI_ISC_CBUS_CMD_RD_SNOOP :
129			`// All the broadcast proccesses were done. This CPU is the initiator`
130			`// of the request. Enable it to continue by send en_wr/en_rd`
131			`!(\|cbus_active_broad_array) &`
132			`// \ /`
133			`cbus_active_en_access_array[3] &`
134			`~broad_fifo_rd_o ?`
135			broad_snoop_type_i == `MESI_ISC_BREQ_TYPE_WR ?
136			`MESI_ISC_CBUS_CMD_EN_WR:
137			`MESI_ISC_CBUS_CMD_EN_RD :
138			`MESI_ISC_CBUS_CMD_NOP;
139			`// \ /`
140			`assign cbus_cmd2 =`
141			`// \ /`
142			`cbus_active_broad_array[2] ?`
143			broad_snoop_type_i == `MESI_ISC_BREQ_TYPE_WR ?
144			`MESI_ISC_CBUS_CMD_WR_SNOOP:
145			`MESI_ISC_CBUS_CMD_RD_SNOOP :
146			`!(\|cbus_active_broad_array) &`
147			`// \ /`
148			`cbus_active_en_access_array[2] &`
149			`~broad_fifo_rd_o ?`
150			broad_snoop_type_i == `MESI_ISC_BREQ_TYPE_WR ?
151			`MESI_ISC_CBUS_CMD_EN_WR:
152			`MESI_ISC_CBUS_CMD_EN_RD :
153			`MESI_ISC_CBUS_CMD_NOP;
154			`// \ /`
155			`assign cbus_cmd1 =`
156			`// \ /`
157			`cbus_active_broad_array[1] ?`
158			broad_snoop_type_i == `MESI_ISC_BREQ_TYPE_WR ?
159			`MESI_ISC_CBUS_CMD_WR_SNOOP:
160			`MESI_ISC_CBUS_CMD_RD_SNOOP :
161			`!(\|cbus_active_broad_array) &`
162			`// \ /`
163			`cbus_active_en_access_array[1] &`
164			`~broad_fifo_rd_o ?`
165			broad_snoop_type_i == `MESI_ISC_BREQ_TYPE_WR ?
166			`MESI_ISC_CBUS_CMD_EN_WR:
167			`MESI_ISC_CBUS_CMD_EN_RD :
168			`MESI_ISC_CBUS_CMD_NOP;
169			`// \ /`
170			`assign cbus_cmd0 =`
171			`// Send read or write broad according to the type of the broad.`
172			`// \ /`
173			`cbus_active_broad_array[0] ?`
174			broad_snoop_type_i == `MESI_ISC_BREQ_TYPE_WR ?
175			`MESI_ISC_CBUS_CMD_WR_SNOOP:
176			`MESI_ISC_CBUS_CMD_RD_SNOOP :
177			`!(\|cbus_active_broad_array) &`
178			`// \ /`
179			`cbus_active_en_access_array[0] &`
180			`~broad_fifo_rd_o ?`
181			broad_snoop_type_i == `MESI_ISC_BREQ_TYPE_WR ?
182			`MESI_ISC_CBUS_CMD_EN_WR:
183			`MESI_ISC_CBUS_CMD_EN_RD :
184
185			`MESI_ISC_CBUS_CMD_NOP;
186
187
188			`// A broadcast process contains 5 sub-processes: Each one of the 4 CPU receives`
189			`// a snoop request and answers with an acknowledge. Then the initiator CPU`
190			`// receives an access enable and answer answers with an acknowledge.`
191			`//`
192			`// The broadcast process stages are:`
193			`// 1. Curently there is no an active process. If there is a valid broadcast to`
194			`// send then:`
195			`// 1.1 broadcast_in_progress <= 1 : It represents an active process of`
196			`// broadcast. It contains 4 snoop sub-processes and 1 enable sub-process.`
197			`// 1.2 cbus_active_broad_array <= 4'b1111 : Each bit represents an active`
198			`// sub-process, for each CPU - sending a snoop request and get an answer`
199			`// with an acknowledge.`
200			`// 1.3 cbus_active_en_access_array[ID of initiator CPU] <= 1`
201			`// The corresponding bit of the initiator CPU in the`
202			`// cbus_active_en_access_array is set to enable in stage 4 to send an`
203			`// enable-access to the initiator CPU.`
204			`// 2. cbus_active_broad_array[ID of CPU] <= 0`
205			`// A snoop request is send for all the CPUs. For each CPU that answers with`
206			`// acknowledge the corresponding bit is clear:`
207			`// cbus_active_broad_array == 0`
208			`// After all CPUs answer with acknowledge all the bits of`
209			`// cbus_active_broad_array are clear.`
210			`// 3. cbus_active_en_access_array[ID of initiator CPU] <= 0`
211			`// broadcast_in_progress <= 0`
212			`// The enable access is sent to the initiator CPU. When it answers with an`
213			`// acknowledge then the broadcast process is finished: the corresponding`
214			`// bit in the cbus_active_en_access_array is clear and`
215			`// the broadcast_in_progress is clear`
216			`//`
217			`//`
218			`// broadcast_in_progress`
219			`// There is an active action of the broadcast. Either not all CPU received the`
220			`// broadcast and return acknowledge. or the initiator CPU received the access`
221			`// enable and return acknowledge.`
222			`//`
223			`// cbus_active_broad_array`
224			`// For each bit, when set - there is an active process of sending a snoop`
225			`// request and answering with an acknowledge.`
226			`//`
227			`// cbus_active_en_access_array`
228			`// For each bit, when set - there is an active process of sending`
229			`// enable-access request to the initiator CPU and receive an acknowledge answer.`
230			`// The enable-access request is send only after all CPUs receive and approve`
231			`// the snoop requests.`
232			`//`
233			`// broad_fifo_rd_o`
234			`// When broadcast process in finish clear the corresponding entry from the fifo`
235			`always @(posedge clk or posedge rst)`
236			`if (rst)`
237			`begin`
238			`broadcast_in_progress <= 0;`
239			`cbus_active_broad_array <= 4'b0000;`
240			`cbus_active_en_access_array <= 4'b0000;`
241			`broad_fifo_rd_o <= 0;`
242			`end`
243			`else if (~broadcast_in_progress & ~broad_fifo_rd_o)`
244			`if (~fifo_status_empty_i)`
245			`// Stage 1`
246			`begin`
247			`broadcast_in_progress <= 1;`
248			`case (broad_snoop_cpu_id_i) // The initiator does not received a`
249			`// broadcast for the same line it asks the`
250			`// broadcast`
251			`0:`
252			`begin`
253			`cbus_active_broad_array <= 4'b1110;`
254			`cbus_active_en_access_array <= 4'b0001;`
255			`end`
256			`1:`
257			`begin`
258			`cbus_active_broad_array <= 4'b1101;`
259			`cbus_active_en_access_array <= 4'b0010;`
260			`end`
261			`2:`
262			`begin`
263			`cbus_active_broad_array <= 4'b1011;`
264			`cbus_active_en_access_array <= 4'b0100;`
265			`end`
266			`3:`
267			`begin`
268			`cbus_active_broad_array <= 4'b0111;`
269			`cbus_active_en_access_array <= 4'b1000;`
270			`end`
271			`default`
272			`begin`
273			`cbus_active_broad_array <= 4'b0000;`
274			`cbus_active_en_access_array <= 4'b0000;`
275			`end`
276			`endcase`
277			`broad_fifo_rd_o <= 0;`
278			`end`
279			`else // if (~fifo_status_empty_i)`
280			`begin`
281			`broadcast_in_progress <= 0;`
282			`cbus_active_broad_array <= 4'b0000;`
283			`cbus_active_en_access_array <= 4'b0000;`
284			`broad_fifo_rd_o <= 0;`
285			`end`
286			`else // if (~broadcast_in_progress)`
287			`// Stage 2`
288			`if (\|cbus_active_broad_array) // There is at least on active snoop`
289			`// sub-process`
290			`begin`
291			`broadcast_in_progress <= 1;`
292			`// Clear related sub-process of a CPU then returns ack for the snoop`
293			`// request.`
294			`cbus_active_broad_array <= cbus_active_broad_array &`
295			`~cbus_ack_array_i;`
296			`cbus_active_en_access_array <= cbus_active_en_access_array;`
297			`broad_fifo_rd_o <= 0;`
298			`end`
299			`// Stage 3`
300			`else if (broad_fifo_rd_o) // All snoop sub-process were done`
301			`begin`
302			`broadcast_in_progress <= 0;`
303			`cbus_active_broad_array <= 0;`
304			`cbus_active_en_access_array <= 0;`
305			`broad_fifo_rd_o <= 0;`
306			`end`
307			`else`
308			`broad_fifo_rd_o <= !(\|(cbus_active_en_access_and_not_cbus_ack_array));`
309
310			`assign cbus_active_en_access_and_not_cbus_ack_array =`
311			`cbus_active_en_access_array & ~cbus_ack_array_i;`
312
313
314			`endmodule`