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[/] [oms8051mini/] [trunk/] [rtl/] [8051/] [oc8051_int.v] - Blame information for rev 25

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1 2 dinesha
//////////////////////////////////////////////////////////////////////
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////                                                              ////
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////  8051 cores interrupt control module                         ////
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////                                                              ////
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////  This file is part of the 8051 cores project                 ////
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////  http://www.opencores.org/cores/oms8051mini/                 ////
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////                                                              ////
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////  Description                                                 ////
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////   contains sfr's: tcon, ip, ie;                              ////
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////   interrupt handling                                         ////
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////                                                              ////
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////  To Do:                                                      ////
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////   Nothing                                                    ////
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////                                                              ////
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////  Author(s):                                                  ////
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////      - Simon Teran, simont@opencores.org                     ////
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////      - Jaka Simsic, jakas@opencores.org                      ////
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////      - Dinesh Annayya, dinesha@opencores.org                 ////
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////                                                              ////
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//////////////////////////////////////////////////////////////////////
21 25 dinesha
////   v0.0 - Dinesh A, 5th Jan 2017
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////        1. Active edge of reset changed from High to Low
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//////////////////////////////////////////////////////////////////////
24 2 dinesha
////                                                              ////
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//// Copyright (C) 2000 Authors and OPENCORES.ORG                 ////
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////                                                              ////
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//// This source file may be used and distributed without         ////
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//// restriction provided that this copyright statement is not    ////
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//// removed from the file and that any derivative work contains  ////
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//// the original copyright notice and the associated disclaimer. ////
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////                                                              ////
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//// This source file is free software; you can redistribute it   ////
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//// and/or modify it under the terms of the GNU Lesser General   ////
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//// Public License as published by the Free Software Foundation; ////
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//// either version 2.1 of the License, or (at your option) any   ////
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//// later version.                                               ////
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////                                                              ////
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//// This source is distributed in the hope that it will be       ////
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//// useful, but WITHOUT ANY WARRANTY; without even the implied   ////
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//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR      ////
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//// PURPOSE.  See the GNU Lesser General Public License for more ////
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//// details.                                                     ////
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////                                                              ////
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//// You should have received a copy of the GNU Lesser General    ////
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//// Public License along with this source; if not, download it   ////
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//// from http://www.opencores.org/lgpl.shtml                     ////
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////                                                              ////
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//////////////////////////////////////////////////////////////////////
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//
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// CVS Revision History
51
//
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// $Log: not supported by cvs2svn $
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// Revision 1.9  2003/06/03 17:12:05  simont
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// fix some bugs.
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//
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// Revision 1.8  2003/04/07 14:58:02  simont
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// change sfr's interface.
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//
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// Revision 1.7  2003/03/28 17:45:57  simont
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// change module name.
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//
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// Revision 1.6  2003/01/13 14:14:41  simont
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// replace some modules
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//
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// Revision 1.5  2002/09/30 17:33:59  simont
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// prepared header
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//
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//
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`include "top_defines.v"
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73
 
74
 
75 25 dinesha
module oc8051_int (clk, resetn,
76 2 dinesha
        wr_addr,
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        data_in, bit_in,
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        wr, wr_bit,
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//timer interrupts
80
        tf0, tf1, t2_int,
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        tr0, tr1,
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//external interrupts
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        ie0, ie1,
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//uart interrupts
85
        uart_int,
86
//to cpu
87
        intr, reti, int_vec, ack,
88
//registers
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        ie, tcon, ip);
90
 
91
input [7:0] wr_addr, data_in;
92 25 dinesha
input wr, tf0, tf1, t2_int, ie0, ie1, clk, resetn, reti, wr_bit, bit_in, ack, uart_int;
93 2 dinesha
 
94
output tr0, tr1, intr;
95
output [7:0] int_vec,
96
             ie,
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             tcon,
98
             ip;
99
 
100
reg [7:0] ip, ie, int_vec;
101
 
102
reg [3:0] tcon_s;
103
reg tcon_tf1, tcon_tf0, tcon_ie1, tcon_ie0;
104
 
105
//
106
// isrc         processing interrupt sources
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// int_dept
108
wire [2:0] isrc_cur;
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reg [2:0] isrc [1:0];
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reg [1:0] int_dept;
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wire [1:0] int_dept_1;
112
reg int_proc;
113
reg [1:0] int_lev [1:0];
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wire cur_lev;
115
 
116
assign isrc_cur = int_proc ? isrc[int_dept_1] : 2'h0;
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assign int_dept_1 = int_dept - 2'b01;
118
assign cur_lev = int_lev[int_dept_1];
119
 
120
//
121
// contains witch level of interrupts is running
122
//reg [1:0] int_levl, int_levl_w;
123
 
124
//
125
// int_ln       waiting interrupts on level n
126
// ip_ln        interrupts on level n
127
// int_src      interrupt sources
128
wire [5:0] int_l0, int_l1;
129
wire [5:0] ip_l0, ip_l1;
130
wire [5:0] int_src;
131
wire il0, il1;
132
 
133
 
134
reg tf0_buff, tf1_buff, ie0_buff, ie1_buff;
135
 
136
//
137
//interrupt priority
138
assign ip_l0 = ~ip[5:0];
139
assign ip_l1 = ip[5:0];
140
 
141
assign int_src = {t2_int, uart_int, tcon_tf1, tcon_ie1, tcon_tf0, tcon_ie0};
142
 
143
//
144
// waiting interrupts
145
assign int_l0 = ip_l0 & {ie[5:0]} & int_src;
146
assign int_l1 = ip_l1 & {ie[5:0]} & int_src;
147
assign il0 = |int_l0;
148
assign il1 = |int_l1;
149
 
150
//
151
// TCON
152
assign tcon = {tcon_tf1, tcon_s[3], tcon_tf0, tcon_s[2], tcon_ie1, tcon_s[1], tcon_ie0, tcon_s[0]};
153
assign tr0 = tcon_s[2];
154
assign tr1 = tcon_s[3];
155
assign intr = |int_vec;
156
 
157
 
158
//
159
// IP
160 25 dinesha
always @(posedge clk or negedge resetn)
161 2 dinesha
begin
162 25 dinesha
 if (resetn == 1'b0) begin
163 2 dinesha
   ip <=#1 `OC8051_RST_IP;
164
 end else if ((wr) & !(wr_bit) & (wr_addr==`OC8051_SFR_IP)) begin
165
   ip <= #1 data_in;
166
 end else if ((wr) & (wr_bit) & (wr_addr[7:3]==`OC8051_SFR_B_IP))
167
   ip[wr_addr[2:0]] <= #1 bit_in;
168
end
169
 
170
//
171
// IE
172 25 dinesha
always @(posedge clk or negedge resetn)
173 2 dinesha
begin
174 25 dinesha
 if (resetn == 1'b0) begin
175 2 dinesha
   ie <=#1 `OC8051_RST_IE;
176
 end else if ((wr) & !(wr_bit) & (wr_addr==`OC8051_SFR_IE)) begin
177
   ie <= #1 data_in;
178
 end else if ((wr) & (wr_bit) & (wr_addr[7:3]==`OC8051_SFR_B_IE))
179
   ie[wr_addr[2:0]] <= #1 bit_in;
180
end
181
 
182
//
183
// tcon_s
184
//
185 25 dinesha
always @(posedge clk or negedge resetn)
186 2 dinesha
begin
187 25 dinesha
 if (resetn == 1'b0) begin
188 2 dinesha
   tcon_s <=#1 4'b0000;
189
 end else if ((wr) & !(wr_bit) & (wr_addr==`OC8051_SFR_TCON)) begin
190
   tcon_s <= #1 {data_in[6], data_in[4], data_in[2], data_in[0]};
191
 end else if ((wr) & (wr_bit) & (wr_addr[7:3]==`OC8051_SFR_B_TCON)) begin
192
   case (wr_addr[2:0]) /* synopsys full_case parallel_case */
193
     3'b000: tcon_s[0] <= #1 bit_in;
194
     3'b010: tcon_s[1] <= #1 bit_in;
195
     3'b100: tcon_s[2] <= #1 bit_in;
196
     3'b110: tcon_s[3] <= #1 bit_in;
197
   endcase
198
 end
199
end
200
 
201
//
202
// tf1 (tmod.7)
203
//
204 25 dinesha
always @(posedge clk or negedge resetn)
205 2 dinesha
begin
206 25 dinesha
 if (resetn == 1'b0) begin
207 2 dinesha
   tcon_tf1 <=#1 1'b0;
208
 end else if ((wr) & !(wr_bit) & (wr_addr==`OC8051_SFR_TCON)) begin
209
   tcon_tf1 <= #1 data_in[7];
210
 end else if ((wr) & (wr_bit) & (wr_addr=={`OC8051_SFR_B_TCON, 3'b111})) begin
211
   tcon_tf1 <= #1 bit_in;
212
 end else if (!(tf1_buff) & (tf1)) begin
213
   tcon_tf1 <= #1 1'b1;
214
 end else if (ack & (isrc_cur==`OC8051_ISRC_TF1)) begin
215
   tcon_tf1 <= #1 1'b0;
216
 end
217
end
218
 
219
//
220
// tf0 (tmod.5)
221
//
222 25 dinesha
always @(posedge clk or negedge resetn)
223 2 dinesha
begin
224 25 dinesha
 if (resetn == 1'b0) begin
225 2 dinesha
   tcon_tf0 <=#1 1'b0;
226
 end else if ((wr) & !(wr_bit) & (wr_addr==`OC8051_SFR_TCON)) begin
227
   tcon_tf0 <= #1 data_in[5];
228
 end else if ((wr) & (wr_bit) & (wr_addr=={`OC8051_SFR_B_TCON, 3'b101})) begin
229
   tcon_tf0 <= #1 bit_in;
230
 end else if (!(tf0_buff) & (tf0)) begin
231
   tcon_tf0 <= #1 1'b1;
232
 end else if (ack & (isrc_cur==`OC8051_ISRC_TF0)) begin
233
   tcon_tf0 <= #1 1'b0;
234
 end
235
end
236
 
237
 
238
//
239
// ie0 (tmod.1)
240
//
241 25 dinesha
always @(posedge clk or negedge resetn)
242 2 dinesha
begin
243 25 dinesha
 if (resetn == 1'b0) begin
244 2 dinesha
   tcon_ie0 <=#1 1'b0;
245
 end else if ((wr) & !(wr_bit) & (wr_addr==`OC8051_SFR_TCON)) begin
246
   tcon_ie0 <= #1 data_in[1];
247
 end else if ((wr) & (wr_bit) & (wr_addr=={`OC8051_SFR_B_TCON, 3'b001})) begin
248
   tcon_ie0 <= #1 bit_in;
249
 end else if (((tcon_s[0]) & (ie0_buff) & !(ie0)) | (!(tcon_s[0]) & !(ie0))) begin
250
   tcon_ie0 <= #1 1'b1;
251
 end else if (ack & (isrc_cur==`OC8051_ISRC_IE0) & (tcon_s[0])) begin
252
   tcon_ie0 <= #1 1'b0;
253
 end else if (!(tcon_s[0]) & (ie0)) begin
254
   tcon_ie0 <= #1 1'b0;
255
 end
256
end
257
 
258
 
259
//
260
// ie1 (tmod.3)
261
//
262 25 dinesha
always @(posedge clk or negedge resetn)
263 2 dinesha
begin
264 25 dinesha
 if (resetn == 1'b0) begin
265 2 dinesha
   tcon_ie1 <=#1 1'b0;
266
 end else if ((wr) & !(wr_bit) & (wr_addr==`OC8051_SFR_TCON)) begin
267
   tcon_ie1 <= #1 data_in[3];
268
 end else if ((wr) & (wr_bit) & (wr_addr=={`OC8051_SFR_B_TCON, 3'b011})) begin
269
   tcon_ie1 <= #1 bit_in;
270
 end else if (((tcon_s[1]) & (ie1_buff) & !(ie1)) | (!(tcon_s[1]) & !(ie1))) begin
271
   tcon_ie1 <= #1 1'b1;
272
 end else if (ack & (isrc_cur==`OC8051_ISRC_IE1) & (tcon_s[1])) begin
273
   tcon_ie1 <= #1 1'b0;
274
 end else if (!(tcon_s[1]) & (ie1)) begin
275
   tcon_ie1 <= #1 1'b0;
276
 end
277
end
278
 
279
//
280
// interrupt processing
281 25 dinesha
always @(posedge clk or negedge resetn)
282 2 dinesha
begin
283 25 dinesha
  if (resetn == 1'b0) begin
284 2 dinesha
    int_vec <= #1 8'h00;
285
    int_dept <= #1 2'b0;
286
    isrc[0] <= #1 3'h0;
287
    isrc[1] <= #1 3'h0;
288
    int_proc <= #1 1'b0;
289
    int_lev[0] <= #1 1'b0;
290
    int_lev[1] <= #1 1'b0;
291
  end else if (reti & int_proc) begin  // return from interrupt
292
   if (int_dept==2'b01)
293
     int_proc <= #1 1'b0;
294
   int_dept <= #1 int_dept - 2'b01;
295
  end else if (((ie[7]) & (!cur_lev) || !int_proc) & il1) begin  // interrupt on level 1
296
   int_proc <= #1 1'b1;
297
   int_lev[int_dept] <= #1 `OC8051_ILEV_L1;
298
   int_dept <= #1 int_dept + 2'b01;
299
   if (int_l1[0]) begin
300
     int_vec <= #1 `OC8051_INT_X0;
301
     isrc[int_dept] <= #1 `OC8051_ISRC_IE0;
302
   end else if (int_l1[1]) begin
303
     int_vec <= #1 `OC8051_INT_T0;
304
     isrc[int_dept] <= #1 `OC8051_ISRC_TF0;
305
   end else if (int_l1[2]) begin
306
     int_vec <= #1 `OC8051_INT_X1;
307
     isrc[int_dept] <= #1 `OC8051_ISRC_IE1;
308
   end else if (int_l1[3]) begin
309
     int_vec <= #1 `OC8051_INT_T1;
310
     isrc[int_dept] <= #1 `OC8051_ISRC_TF1;
311
   end else if (int_l1[4]) begin
312
     int_vec <= #1 `OC8051_INT_UART;
313
     isrc[int_dept] <= #1 `OC8051_ISRC_UART;
314
   end else if (int_l1[5]) begin
315
     int_vec <= #1 `OC8051_INT_T2;
316
     isrc[int_dept] <= #1 `OC8051_ISRC_T2;
317
   end
318
 
319
 end else if ((ie[7]) & !int_proc & il0) begin  // interrupt on level 0
320
   int_proc <= #1 1'b1;
321
   int_lev[int_dept] <= #1 `OC8051_ILEV_L0;
322
   int_dept <= #1 2'b01;
323
   if (int_l0[0]) begin
324
     int_vec <= #1 `OC8051_INT_X0;
325
     isrc[int_dept] <= #1 `OC8051_ISRC_IE0;
326
   end else if (int_l0[1]) begin
327
     int_vec <= #1 `OC8051_INT_T0;
328
     isrc[int_dept] <= #1 `OC8051_ISRC_TF0;
329
   end else if (int_l0[2]) begin
330
     int_vec <= #1 `OC8051_INT_X1;
331
     isrc[int_dept] <= #1 `OC8051_ISRC_IE1;
332
   end else if (int_l0[3]) begin
333
     int_vec <= #1 `OC8051_INT_T1;
334
     isrc[int_dept] <= #1 `OC8051_ISRC_TF1;
335
   end else if (int_l0[4]) begin
336
     int_vec <= #1 `OC8051_INT_UART;
337
     isrc[int_dept] <= #1 `OC8051_ISRC_UART;
338
   end else if (int_l0[5]) begin
339
     int_vec <= #1 `OC8051_INT_T2;
340
     isrc[int_dept] <= #1 `OC8051_ISRC_T2;
341
   end
342
 end else begin
343
   int_vec <= #1 8'h00;
344
 end
345
end
346
 
347
 
348 25 dinesha
always @(posedge clk or negedge resetn)
349
  if (resetn == 1'b0) begin
350 2 dinesha
    tf0_buff <= #1 1'b0;
351
    tf1_buff <= #1 1'b0;
352
    ie0_buff <= #1 1'b0;
353
    ie1_buff <= #1 1'b0;
354
  end else begin
355
    tf0_buff <= #1 tf0;
356
    tf1_buff <= #1 tf1;
357
    ie0_buff <= #1 ie0;
358
    ie1_buff <= #1 ie1;
359
  end
360
 
361
endmodule

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