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[/] [openrisc/] [trunk/] [orpsocv2/] [rtl/] [verilog/] [wb_ram_b3/] [wb_ram_b3.v] - Blame information for rev 360

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// Version 5
 
`define NONBLOCK_ASSIGN <=
 
//`define RANDOM_ACK_NEGATION
 
module wb_ram_b3(
                 wb_adr_i, wb_bte_i, wb_cti_i, wb_cyc_i, wb_dat_i, wb_sel_i,
                 wb_stb_i, wb_we_i,
 
                 wb_ack_o, wb_err_o, wb_rty_o, wb_dat_o,
 
                 wb_clk_i, wb_rst_i);
 
   // Memory parameters
   parameter dw = 32;
 
   // 32MB memory by default
   parameter aw = 25;
   parameter mem_size  = 8388608;
 
   input [aw-1:0]        wb_adr_i;
   input [1:0]           wb_bte_i;
   input [2:0]           wb_cti_i;
   input                wb_cyc_i;
   input [dw-1:0]        wb_dat_i;
   input [3:0]           wb_sel_i;
   input                wb_stb_i;
   input                wb_we_i;
 
   output               wb_ack_o;
   output               wb_err_o;
   output               wb_rty_o;
   output [dw-1:0]       wb_dat_o;
 
   input                wb_clk_i;
   input                wb_rst_i;
 
 
   // synthesis attribute ram_style of mem is block
   reg [dw-1:0]  mem [ 0 : mem_size-1 ]  /* verilator public */ /* synthesis ram_style = no_rw_check */;
 
   //reg [aw-1:2] wb_adr_i_r;
   reg [(aw-2)-1:0] adr;
 
   wire [31:0]                      wr_data;
 
   // Register to indicate if the cycle is a Wishbone B3-registered feedback 
   // type access
   reg                             wb_b3_trans;
   wire                            wb_b3_trans_start, wb_b3_trans_stop;
 
   // Register to use for counting the addresses when doing burst accesses
   reg [aw-1-2:0]  burst_adr_counter;
   reg [2:0]                        wb_cti_i_r;
   reg [1:0]                        wb_bte_i_r;
   wire                            using_burst_adr;
   wire                            burst_access_wrong_wb_adr;
 
   reg                             random_ack_negate;
 
   // Logic to detect if there's a burst access going on
   assign wb_b3_trans_start = ((wb_cti_i == 3'b001)|(wb_cti_i == 3'b010)) &
                              wb_stb_i & !wb_b3_trans;
 
   assign  wb_b3_trans_stop = (wb_cti_i == 3'b111) &
                              wb_stb_i & wb_b3_trans & wb_ack_o;
 
   always @(posedge wb_clk_i)
     if (wb_rst_i)
       wb_b3_trans <= 0;
     else if (wb_b3_trans_start)
       wb_b3_trans <= 1;
     else if (wb_b3_trans_stop)
       wb_b3_trans <= 0;
 
   // Burst address generation logic
   always @*
     if (wb_rst_i)
       burst_adr_counter = 0;
     else if (wb_b3_trans_start)
       burst_adr_counter = wb_adr_i[aw-1:2];
     else if ((wb_cti_i_r == 3'b010) & wb_ack_o & wb_b3_trans)
       // Incrementing burst
       begin
          if (wb_bte_i_r == 2'b00) // Linear burst
            burst_adr_counter = adr + 1;
          if (wb_bte_i_r == 2'b01) // 4-beat wrap burst
            burst_adr_counter[1:0] = adr[1:0] + 1;
          if (wb_bte_i_r == 2'b10) // 8-beat wrap burst
            burst_adr_counter[2:0] = adr[2:0] + 1;
          if (wb_bte_i_r == 2'b11) // 16-beat wrap burst
            burst_adr_counter[3:0] = adr[3:0] + 1;
       end // if ((wb_cti_i_r == 3'b010) & wb_ack_o_r)
     else if (!wb_ack_o & wb_b3_trans)
            burst_adr_counter = adr;
 
 
   always @(posedge wb_clk_i)
     wb_bte_i_r <= wb_bte_i;
 
   // Register it locally
   always @(posedge wb_clk_i)
     wb_cti_i_r <= wb_cti_i;
 
   assign using_burst_adr = wb_b3_trans;
 
   assign burst_access_wrong_wb_adr = (using_burst_adr & (adr != wb_adr_i[aw-1:2]));
 
   // Address registering logic
   always@(posedge wb_clk_i)
     if(wb_rst_i)
       adr <= 0;
     else if (using_burst_adr)
       adr <= burst_adr_counter;
     else if (wb_cyc_i & wb_stb_i)
       adr <= wb_adr_i[aw-1:2];
 
   parameter memory_file = "sram.vmem";
 
 
`ifdef verilator
 
   task do_readmemh;
      // verilator public
      $readmemh(memory_file, mem);
   endtask // do_readmemh
 
`else
 
   initial
     begin
        $readmemh(memory_file, mem);
     end
 
`endif // !`ifdef verilator
 
 
   // Function to access RAM (for use by Verilator).
   function [31:0] get_mem;
      // verilator public
      input [aw-1:0]             addr;
      get_mem = mem[addr];
   endfunction // get_mem
 
   // Function to write RAM (for use by Verilator).
   function set_mem;
      // verilator public
      input [aw-1:0]             addr;
      input [dw-1:0]             data;
      mem[addr] = data;
   endfunction // set_mem
 
 
   assign wb_rty_o = 0;
 
   // mux for data to ram, RMW on part sel != 4'hf
   assign wr_data[31:24] = wb_sel_i[3] ? wb_dat_i[31:24] : wb_dat_o[31:24];
   assign wr_data[23:16] = wb_sel_i[2] ? wb_dat_i[23:16] : wb_dat_o[23:16];
   assign wr_data[15: 8] = wb_sel_i[1] ? wb_dat_i[15: 8] : wb_dat_o[15: 8];
   assign wr_data[ 7: 0] = wb_sel_i[0] ? wb_dat_i[ 7: 0] : wb_dat_o[ 7: 0];
 
   // Address logic
   /*
   always @(posedge wb_clk_i)
     begin
        if (wb_rst_i)
          wb_adr_i_r <= 0;
        else
          if (wb_cyc_i & wb_stb_i)
            wb_adr_i_r <= wb_adr_i[aw-1:2];
     end
    */
 
   wire ram_we;
   assign ram_we = wb_we_i & wb_ack_o;
 
   assign wb_dat_o = mem[adr];
 
   // Write logic
   always @ (posedge wb_clk_i)
     begin
        if (ram_we)
          mem[adr] <= wr_data;
     end
 
   // Ack Logic
   reg wb_ack_o_r;
 
   assign wb_ack_o = wb_ack_o_r & wb_stb_i;
 
   always @(posedge wb_clk_i)
     if (wb_rst_i)
       begin
          wb_ack_o_r <= 1'b0;
       end
     else if (wb_cyc_i) // We have bus
       begin
          if (wb_cti_i == 3'b111)
            begin
               // End of burst
               if (wb_ack_o_r)
                 // ALWAYS de-assert ack after burst end
                 wb_ack_o_r <= 0;
               else if (wb_stb_i & !random_ack_negate)
                 wb_ack_o_r <= 1;
               else
                 wb_ack_o_r <= 0;
            end
          else if (wb_cti_i == 3'b000)
            begin
               // Classic cycle acks
               if (wb_stb_i & !random_ack_negate)
                 begin
                    if (!wb_ack_o_r)
                      wb_ack_o_r <= 1;
                    else
                      wb_ack_o_r <= 0;
                 end
               else
                 wb_ack_o_r <= 0;
            end // if (wb_cti_i == 3'b000)
          else if ((wb_cti_i == 3'b001) | (wb_cti_i == 3'b010))
            begin
               // Increment/constant address bursts
               if (wb_stb_i & !random_ack_negate)
                 wb_ack_o_r <= 1;
               else
                 wb_ack_o_r <= 0;
            end
          else if (wb_cti_i == 3'b111)
            begin
               // End of cycle
               if (wb_stb_i & !random_ack_negate)
                 wb_ack_o_r <= 1;
               else
                 wb_ack_o_r <= 0;
            end
       end // if (wb_cyc_i)
     else
       wb_ack_o_r <= 0;
 
   assign wb_err_o = 1'b0;// wb_ack_o & (burst_access_wrong_wb_adr); // OR in other errors here
 
 
   // Random ACK negation logic
`ifdef RANDOM_ACK_NEGATION
   reg [31:0] lfsr;
   always @(posedge wb_clk_i)
     if (wb_rst_i)
       lfsr <= 32'h273e2d4a;
     else lfsr <= {lfsr[30:0], ~(lfsr[30]^lfsr[6]^lfsr[4]^lfsr[1]^lfsr[0])};
 
   always @(posedge wb_clk_i)
     random_ack_negate <= lfsr[26];
 
`else
   always @(wb_rst_i)
     random_ack_negate = 0;
`endif
 
 
 
endmodule // wb_ram_b3_v2
 

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[/] [openrisc/] [trunk/] [orpsocv2/] [rtl/] [verilog/] [wb_ram_b3/] [wb_ram_b3.v] - Blame information for rev 360

Line No.	Rev	Author	Line
1	351	julius
2			`// Version 5`
3
4			`define NONBLOCK_ASSIGN <=
5
6			//`define RANDOM_ACK_NEGATION
7
8			`module wb_ram_b3(`
9			`wb_adr_i, wb_bte_i, wb_cti_i, wb_cyc_i, wb_dat_i, wb_sel_i,`
10			`wb_stb_i, wb_we_i,`
11
12			`wb_ack_o, wb_err_o, wb_rty_o, wb_dat_o,`
13
14			`wb_clk_i, wb_rst_i);`
15
16			`// Memory parameters`
17			`parameter dw = 32;`
18
19			`// 32MB memory by default`
20			`parameter aw = 25;`
21			`parameter mem_size = 8388608;`
22
23			`input [aw-1:0] wb_adr_i;`
24			`input [1:0] wb_bte_i;`
25			`input [2:0] wb_cti_i;`
26			`input wb_cyc_i;`
27			`input [dw-1:0] wb_dat_i;`
28			`input [3:0] wb_sel_i;`
29			`input wb_stb_i;`
30			`input wb_we_i;`
31
32			`output wb_ack_o;`
33			`output wb_err_o;`
34			`output wb_rty_o;`
35			`output [dw-1:0] wb_dat_o;`
36
37			`input wb_clk_i;`
38			`input wb_rst_i;`
39
40
41			`// synthesis attribute ram_style of mem is block`
42			`reg [dw-1:0] mem [ 0 : mem_size-1 ] /* verilator public / / synthesis ram_style = no_rw_check */;`
43
44			`//reg [aw-1:2] wb_adr_i_r;`
45			`reg [(aw-2)-1:0] adr;`
46
47			`wire [31:0] wr_data;`
48
49			`// Register to indicate if the cycle is a Wishbone B3-registered feedback`
50			`// type access`
51			`reg wb_b3_trans;`
52			`wire wb_b3_trans_start, wb_b3_trans_stop;`
53
54			`// Register to use for counting the addresses when doing burst accesses`
55			`reg [aw-1-2:0] burst_adr_counter;`
56			`reg [2:0] wb_cti_i_r;`
57			`reg [1:0] wb_bte_i_r;`
58			`wire using_burst_adr;`
59			`wire burst_access_wrong_wb_adr;`
60
61			`reg random_ack_negate;`
62
63			`// Logic to detect if there's a burst access going on`
64			`assign wb_b3_trans_start = ((wb_cti_i == 3'b001)\|(wb_cti_i == 3'b010)) &`
65			`wb_stb_i & !wb_b3_trans;`
66
67			`assign wb_b3_trans_stop = (wb_cti_i == 3'b111) &`
68			`wb_stb_i & wb_b3_trans & wb_ack_o;`
69
70			`always @(posedge wb_clk_i)`
71			`if (wb_rst_i)`
72			`wb_b3_trans <= 0;`
73			`else if (wb_b3_trans_start)`
74			`wb_b3_trans <= 1;`
75			`else if (wb_b3_trans_stop)`
76			`wb_b3_trans <= 0;`
77
78			`// Burst address generation logic`
79	353	julius	`always @*`
80	351	julius	`if (wb_rst_i)`
81	353	julius	`burst_adr_counter = 0;`
82	351	julius	`else if (wb_b3_trans_start)`
83	353	julius	`burst_adr_counter = wb_adr_i[aw-1:2];`
84	351	julius	`else if ((wb_cti_i_r == 3'b010) & wb_ack_o & wb_b3_trans)`
85			`// Incrementing burst`
86			`begin`
87			`if (wb_bte_i_r == 2'b00) // Linear burst`
88	353	julius	`burst_adr_counter = adr + 1;`
89	351	julius	`if (wb_bte_i_r == 2'b01) // 4-beat wrap burst`
90	353	julius	`burst_adr_counter[1:0] = adr[1:0] + 1;`
91	351	julius	`if (wb_bte_i_r == 2'b10) // 8-beat wrap burst`
92	353	julius	`burst_adr_counter[2:0] = adr[2:0] + 1;`
93	351	julius	`if (wb_bte_i_r == 2'b11) // 16-beat wrap burst`
94	353	julius	`burst_adr_counter[3:0] = adr[3:0] + 1;`
95	351	julius	`end // if ((wb_cti_i_r == 3'b010) & wb_ack_o_r)`
96			`else if (!wb_ack_o & wb_b3_trans)`
97	353	julius	`burst_adr_counter = adr;`
98	351	julius
99
100			`always @(posedge wb_clk_i)`
101			`wb_bte_i_r <= wb_bte_i;`
102
103			`// Register it locally`
104			`always @(posedge wb_clk_i)`
105			`wb_cti_i_r <= wb_cti_i;`
106
107			`assign using_burst_adr = wb_b3_trans;`
108
109			`assign burst_access_wrong_wb_adr = (using_burst_adr & (adr != wb_adr_i[aw-1:2]));`
110
111			`// Address registering logic`
112			`always@(posedge wb_clk_i)`
113			`if(wb_rst_i)`
114			`adr <= 0;`
115			`else if (using_burst_adr)`
116			`adr <= burst_adr_counter;`
117			`else if (wb_cyc_i & wb_stb_i)`
118			`adr <= wb_adr_i[aw-1:2];`
119
120			`parameter memory_file = "sram.vmem";`
121
122
123			`ifdef verilator
124
125			`task do_readmemh;`
126			`// verilator public`
127			`$readmemh(memory_file, mem);`
128			`endtask // do_readmemh`
129
130			`else
131
132			`initial`
133			`begin`
134			`$readmemh(memory_file, mem);`
135			`end`
136
137			`endif // !`ifdef verilator
138
139
140			`// Function to access RAM (for use by Verilator).`
141			`function [31:0] get_mem;`
142			`// verilator public`
143			`input [aw-1:0] addr;`
144			`get_mem = mem[addr];`
145			`endfunction // get_mem`
146
147			`// Function to write RAM (for use by Verilator).`
148			`function set_mem;`
149			`// verilator public`
150			`input [aw-1:0] addr;`
151			`input [dw-1:0] data;`
152			`mem[addr] = data;`
153			`endfunction // set_mem`
154
155
156			`assign wb_rty_o = 0;`
157
158			`// mux for data to ram, RMW on part sel != 4'hf`
159			`assign wr_data[31:24] = wb_sel_i[3] ? wb_dat_i[31:24] : wb_dat_o[31:24];`
160			`assign wr_data[23:16] = wb_sel_i[2] ? wb_dat_i[23:16] : wb_dat_o[23:16];`
161			`assign wr_data[15: 8] = wb_sel_i[1] ? wb_dat_i[15: 8] : wb_dat_o[15: 8];`
162			`assign wr_data[ 7: 0] = wb_sel_i[0] ? wb_dat_i[ 7: 0] : wb_dat_o[ 7: 0];`
163
164			`// Address logic`
165			`/*`
166			`always @(posedge wb_clk_i)`
167			`begin`
168			`if (wb_rst_i)`
169			`wb_adr_i_r <= 0;`
170			`else`
171			`if (wb_cyc_i & wb_stb_i)`
172			`wb_adr_i_r <= wb_adr_i[aw-1:2];`
173			`end`
174			`*/`
175
176			`wire ram_we;`
177			`assign ram_we = wb_we_i & wb_ack_o;`
178
179			`assign wb_dat_o = mem[adr];`
180
181			`// Write logic`
182			`always @ (posedge wb_clk_i)`
183			`begin`
184			`if (ram_we)`
185			`mem[adr] <= wr_data;`
186			`end`
187
188			`// Ack Logic`
189			`reg wb_ack_o_r;`
190
191			`assign wb_ack_o = wb_ack_o_r & wb_stb_i;`
192
193	353	julius	`always @(posedge wb_clk_i)`
194	351	julius	`if (wb_rst_i)`
195			`begin`
196			`wb_ack_o_r <= 1'b0;`
197			`end`
198			`else if (wb_cyc_i) // We have bus`
199			`begin`
200			`if (wb_cti_i == 3'b111)`
201			`begin`
202			`// End of burst`
203			`if (wb_ack_o_r)`
204			`// ALWAYS de-assert ack after burst end`
205			`wb_ack_o_r <= 0;`
206			`else if (wb_stb_i & !random_ack_negate)`
207			`wb_ack_o_r <= 1;`
208			`else`
209			`wb_ack_o_r <= 0;`
210			`end`
211			`else if (wb_cti_i == 3'b000)`
212			`begin`
213			`// Classic cycle acks`
214			`if (wb_stb_i & !random_ack_negate)`
215			`begin`
216			`if (!wb_ack_o_r)`
217			`wb_ack_o_r <= 1;`
218			`else`
219			`wb_ack_o_r <= 0;`
220			`end`
221			`else`
222			`wb_ack_o_r <= 0;`
223			`end // if (wb_cti_i == 3'b000)`
224			`else if ((wb_cti_i == 3'b001) \| (wb_cti_i == 3'b010))`
225			`begin`
226			`// Increment/constant address bursts`
227			`if (wb_stb_i & !random_ack_negate)`
228			`wb_ack_o_r <= 1;`
229			`else`
230			`wb_ack_o_r <= 0;`
231			`end`
232			`else if (wb_cti_i == 3'b111)`
233			`begin`
234			`// End of cycle`
235			`if (wb_stb_i & !random_ack_negate)`
236			`wb_ack_o_r <= 1;`
237			`else`
238			`wb_ack_o_r <= 0;`
239			`end`
240			`end // if (wb_cyc_i)`
241			`else`
242			`wb_ack_o_r <= 0;`
243
244			`assign wb_err_o = 1'b0;// wb_ack_o & (burst_access_wrong_wb_adr); // OR in other errors here`
245
246
247			`// Random ACK negation logic`
248			`ifdef RANDOM_ACK_NEGATION
249			`reg [31:0] lfsr;`
250			`always @(posedge wb_clk_i)`
251			`if (wb_rst_i)`
252			`lfsr <= 32'h273e2d4a;`
253			`else lfsr <= {lfsr[30:0], ~(lfsr[30]^lfsr[6]^lfsr[4]^lfsr[1]^lfsr[0])};`
254
255			`always @(posedge wb_clk_i)`
256			`random_ack_negate <= lfsr[26];`
257
258			`else
259			`always @(wb_rst_i)`
260	353	julius	`random_ack_negate = 0;`
261	351	julius	`endif
262
263
264
265			`endmodule // wb_ram_b3_v2`
266