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[/] [wb_conbus/] [trunk/] [rtl/] [verilog/] [wb_conbus_arb.v] - Blame information for rev 8

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/////////////////////////////////////////////////////////////////////
////                                                             ////
////  General Round Robin Arbiter                                ////
////                                                             ////
////                                                             ////
////  Author: Rudolf Usselmann                                   ////
////          rudi@asics.ws                                      ////
////                                                             ////
////                                                             ////
////  Downloaded from: http://www.opencores.org/cores/wb_conmax/ ////
////                                                             ////
/////////////////////////////////////////////////////////////////////
////                                                             ////
//// Copyright (C) 2000-2002 Rudolf Usselmann                    ////
////                         www.asics.ws                        ////
////                         rudi@asics.ws                       ////
////                                                             ////
//// 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 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.                                 ////
////                                                             ////
/////////////////////////////////////////////////////////////////////
 
 
//
//      copy from wb_conmax
//
//
//
//
//                        
 
`include "wb_conbus_defines.v"
 
module wb_conbus_arb(clk, rst, req, gnt);
 
input           clk;
input           rst;
input   [7:0]    req;            // Req input
output  [2:0]    gnt;            // Grant output
//input         next;           // Next Target
 
///////////////////////////////////////////////////////////////////////
//
// Parameters
//
 
 
parameter       [2:0]
                grant0 = 3'h0,
                grant1 = 3'h1,
                grant2 = 3'h2,
                grant3 = 3'h3,
                grant4 = 3'h4,
                grant5 = 3'h5,
                grant6 = 3'h6,
                grant7 = 3'h7;
 
///////////////////////////////////////////////////////////////////////
//
// Local Registers and Wires
//
 
reg [2:0]        state, next_state;
 
///////////////////////////////////////////////////////////////////////
//
//  Misc Logic 
//
 
assign  gnt = state;
 
always@(posedge clk or posedge rst)
        if(rst)         state <= #1 grant0;
        else            state <= #1 next_state;
 
///////////////////////////////////////////////////////////////////////
//
// Next State Logic
//   - implements round robin arbitration algorithm
//   - switches grant if current req is dropped or next is asserted
//   - parks at last grant
//
 
always@(state or req )
   begin
        next_state = state;     // Default Keep State
        case(state)             // synopsys parallel_case full_case
           grant0:
                // if this req is dropped or next is asserted, check for other req's
                if(!req[0] )
                   begin
                        if(req[1])      next_state = grant1;
                        else
                        if(req[2])      next_state = grant2;
                        else
                        if(req[3])      next_state = grant3;
                        else
                        if(req[4])      next_state = grant4;
                        else
                        if(req[5])      next_state = grant5;
                        else
                        if(req[6])      next_state = grant6;
                        else
                        if(req[7])      next_state = grant7;
                   end
           grant1:
                // if this req is dropped or next is asserted, check for other req's
                if(!req[1] )
                   begin
                        if(req[2])      next_state = grant2;
                        else
                        if(req[3])      next_state = grant3;
                        else
                        if(req[4])      next_state = grant4;
                        else
                        if(req[5])      next_state = grant5;
                        else
                        if(req[6])      next_state = grant6;
                        else
                        if(req[7])      next_state = grant7;
                        else
                        if(req[0])       next_state = grant0;
                   end
           grant2:
                // if this req is dropped or next is asserted, check for other req's
                if(!req[2] )
                   begin
                        if(req[3])      next_state = grant3;
                        else
                        if(req[4])      next_state = grant4;
                        else
                        if(req[5])      next_state = grant5;
                        else
                        if(req[6])      next_state = grant6;
                        else
                        if(req[7])      next_state = grant7;
                        else
                        if(req[0])       next_state = grant0;
                        else
                        if(req[1])      next_state = grant1;
                   end
           grant3:
                // if this req is dropped or next is asserted, check for other req's
                if(!req[3] )
                   begin
                        if(req[4])      next_state = grant4;
                        else
                        if(req[5])      next_state = grant5;
                        else
                        if(req[6])      next_state = grant6;
                        else
                        if(req[7])      next_state = grant7;
                        else
                        if(req[0])       next_state = grant0;
                        else
                        if(req[1])      next_state = grant1;
                        else
                        if(req[2])      next_state = grant2;
                   end
           grant4:
                // if this req is dropped or next is asserted, check for other req's
                if(!req[4] )
                   begin
                        if(req[5])      next_state = grant5;
                        else
                        if(req[6])      next_state = grant6;
                        else
                        if(req[7])      next_state = grant7;
                        else
                        if(req[0])       next_state = grant0;
                        else
                        if(req[1])      next_state = grant1;
                        else
                        if(req[2])      next_state = grant2;
                        else
                        if(req[3])      next_state = grant3;
                   end
           grant5:
                // if this req is dropped or next is asserted, check for other req's
                if(!req[5] )
                   begin
                        if(req[6])      next_state = grant6;
                        else
                        if(req[7])      next_state = grant7;
                        else
                        if(req[0])       next_state = grant0;
                        else
                        if(req[1])      next_state = grant1;
                        else
                        if(req[2])      next_state = grant2;
                        else
                        if(req[3])      next_state = grant3;
                        else
                        if(req[4])      next_state = grant4;
                   end
           grant6:
                // if this req is dropped or next is asserted, check for other req's
                if(!req[6] )
                   begin
                        if(req[7])      next_state = grant7;
                        else
                        if(req[0])       next_state = grant0;
                        else
                        if(req[1])      next_state = grant1;
                        else
                        if(req[2])      next_state = grant2;
                        else
                        if(req[3])      next_state = grant3;
                        else
                        if(req[4])      next_state = grant4;
                        else
                        if(req[5])      next_state = grant5;
                   end
           grant7:
                // if this req is dropped or next is asserted, check for other req's
                if(!req[7] )
                   begin
                        if(req[0])       next_state = grant0;
                        else
                        if(req[1])      next_state = grant1;
                        else
                        if(req[2])      next_state = grant2;
                        else
                        if(req[3])      next_state = grant3;
                        else
                        if(req[4])      next_state = grant4;
                        else
                        if(req[5])      next_state = grant5;
                        else
                        if(req[6])      next_state = grant6;
                   end
        endcase
   end
 
endmodule
 

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Subversion Repositories wb_conbus

[/] [wb_conbus/] [trunk/] [rtl/] [verilog/] [wb_conbus_arb.v] - Blame information for rev 8

Line No.	Rev	Author	Line
1	2	johny	`/////////////////////////////////////////////////////////////////////`
2			`//// ////`
3			`//// General Round Robin Arbiter ////`
4			`//// ////`
5			`//// ////`
6			`//// Author: Rudolf Usselmann ////`
7			`//// rudi@asics.ws ////`
8			`//// ////`
9			`//// ////`
10			`//// Downloaded from: http://www.opencores.org/cores/wb_conmax/ ////`
11			`//// ////`
12			`/////////////////////////////////////////////////////////////////////`
13			`//// ////`
14			`//// Copyright (C) 2000-2002 Rudolf Usselmann ////`
15			`//// www.asics.ws ////`
16			`//// rudi@asics.ws ////`
17			`//// ////`
18			`//// This source file may be used and distributed without ////`
19			`//// restriction provided that this copyright statement is not ////`
20			`//// removed from the file and that any derivative work contains ////`
21			`//// the original copyright notice and the associated disclaimer.////`
22			`//// ////`
23			//// THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY ////
24			`//// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED ////`
25			`//// TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS ////`
26			`//// FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL THE AUTHOR ////`
27			`//// OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, ////`
28			`//// INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES ////`
29			`//// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE ////`
30			`//// GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR ////`
31			`//// BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF ////`
32			`//// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT ////`
33			`//// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT ////`
34			`//// OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE ////`
35			`//// POSSIBILITY OF SUCH DAMAGE. ////`
36			`//// ////`
37			`/////////////////////////////////////////////////////////////////////`
38
39
40			`//`
41			`// copy from wb_conmax`
42			`//`
43			`//`
44			`//`
45			`//`
46			`//`
47
48			`include "wb_conbus_defines.v"
49
50			`module wb_conbus_arb(clk, rst, req, gnt);`
51
52			`input clk;`
53			`input rst;`
54			`input [7:0] req; // Req input`
55			`output [2:0] gnt; // Grant output`
56			`//input next; // Next Target`
57
58			`///////////////////////////////////////////////////////////////////////`
59			`//`
60			`// Parameters`
61			`//`
62
63
64			`parameter [2:0]`
65			`grant0 = 3'h0,`
66			`grant1 = 3'h1,`
67			`grant2 = 3'h2,`
68			`grant3 = 3'h3,`
69			`grant4 = 3'h4,`
70			`grant5 = 3'h5,`
71			`grant6 = 3'h6,`
72			`grant7 = 3'h7;`
73
74			`///////////////////////////////////////////////////////////////////////`
75			`//`
76			`// Local Registers and Wires`
77			`//`
78
79			`reg [2:0] state, next_state;`
80
81			`///////////////////////////////////////////////////////////////////////`
82			`//`
83			`// Misc Logic`
84			`//`
85
86			`assign gnt = state;`
87
88			`always@(posedge clk or posedge rst)`
89			`if(rst) state <= #1 grant0;`
90			`else state <= #1 next_state;`
91
92			`///////////////////////////////////////////////////////////////////////`
93			`//`
94			`// Next State Logic`
95			`// - implements round robin arbitration algorithm`
96			`// - switches grant if current req is dropped or next is asserted`
97			`// - parks at last grant`
98			`//`
99
100			`always@(state or req )`
101			`begin`
102			`next_state = state; // Default Keep State`
103			`case(state) // synopsys parallel_case full_case`
104			`grant0:`
105			`// if this req is dropped or next is asserted, check for other req's`
106			`if(!req[0] )`
107			`begin`
108			`if(req[1]) next_state = grant1;`
109			`else`
110			`if(req[2]) next_state = grant2;`
111			`else`
112			`if(req[3]) next_state = grant3;`
113			`else`
114			`if(req[4]) next_state = grant4;`
115			`else`
116			`if(req[5]) next_state = grant5;`
117			`else`
118			`if(req[6]) next_state = grant6;`
119			`else`
120			`if(req[7]) next_state = grant7;`
121			`end`
122			`grant1:`
123			`// if this req is dropped or next is asserted, check for other req's`
124			`if(!req[1] )`
125			`begin`
126			`if(req[2]) next_state = grant2;`
127			`else`
128			`if(req[3]) next_state = grant3;`
129			`else`
130			`if(req[4]) next_state = grant4;`
131			`else`
132			`if(req[5]) next_state = grant5;`
133			`else`
134			`if(req[6]) next_state = grant6;`
135			`else`
136			`if(req[7]) next_state = grant7;`
137			`else`
138			`if(req[0]) next_state = grant0;`
139			`end`
140			`grant2:`
141			`// if this req is dropped or next is asserted, check for other req's`
142			`if(!req[2] )`
143			`begin`
144			`if(req[3]) next_state = grant3;`
145			`else`
146			`if(req[4]) next_state = grant4;`
147			`else`
148			`if(req[5]) next_state = grant5;`
149			`else`
150			`if(req[6]) next_state = grant6;`
151			`else`
152			`if(req[7]) next_state = grant7;`
153			`else`
154			`if(req[0]) next_state = grant0;`
155			`else`
156			`if(req[1]) next_state = grant1;`
157			`end`
158			`grant3:`
159			`// if this req is dropped or next is asserted, check for other req's`
160			`if(!req[3] )`
161			`begin`
162			`if(req[4]) next_state = grant4;`
163			`else`
164			`if(req[5]) next_state = grant5;`
165			`else`
166			`if(req[6]) next_state = grant6;`
167			`else`
168			`if(req[7]) next_state = grant7;`
169			`else`
170			`if(req[0]) next_state = grant0;`
171			`else`
172			`if(req[1]) next_state = grant1;`
173			`else`
174			`if(req[2]) next_state = grant2;`
175			`end`
176			`grant4:`
177			`// if this req is dropped or next is asserted, check for other req's`
178			`if(!req[4] )`
179			`begin`
180			`if(req[5]) next_state = grant5;`
181			`else`
182			`if(req[6]) next_state = grant6;`
183			`else`
184			`if(req[7]) next_state = grant7;`
185			`else`
186			`if(req[0]) next_state = grant0;`
187			`else`
188			`if(req[1]) next_state = grant1;`
189			`else`
190			`if(req[2]) next_state = grant2;`
191			`else`
192			`if(req[3]) next_state = grant3;`
193			`end`
194			`grant5:`
195			`// if this req is dropped or next is asserted, check for other req's`
196			`if(!req[5] )`
197			`begin`
198			`if(req[6]) next_state = grant6;`
199			`else`
200			`if(req[7]) next_state = grant7;`
201			`else`
202			`if(req[0]) next_state = grant0;`
203			`else`
204			`if(req[1]) next_state = grant1;`
205			`else`
206			`if(req[2]) next_state = grant2;`
207			`else`
208			`if(req[3]) next_state = grant3;`
209			`else`
210			`if(req[4]) next_state = grant4;`
211			`end`
212			`grant6:`
213			`// if this req is dropped or next is asserted, check for other req's`
214			`if(!req[6] )`
215			`begin`
216			`if(req[7]) next_state = grant7;`
217			`else`
218			`if(req[0]) next_state = grant0;`
219			`else`
220			`if(req[1]) next_state = grant1;`
221			`else`
222			`if(req[2]) next_state = grant2;`
223			`else`
224			`if(req[3]) next_state = grant3;`
225			`else`
226			`if(req[4]) next_state = grant4;`
227			`else`
228			`if(req[5]) next_state = grant5;`
229			`end`
230			`grant7:`
231			`// if this req is dropped or next is asserted, check for other req's`
232			`if(!req[7] )`
233			`begin`
234			`if(req[0]) next_state = grant0;`
235			`else`
236			`if(req[1]) next_state = grant1;`
237			`else`
238			`if(req[2]) next_state = grant2;`
239			`else`
240			`if(req[3]) next_state = grant3;`
241			`else`
242			`if(req[4]) next_state = grant4;`
243			`else`
244			`if(req[5]) next_state = grant5;`
245			`else`
246			`if(req[6]) next_state = grant6;`
247			`end`
248			`endcase`
249			`end`
250
251			`endmodule`
252