forked from ATaylorCEngFIET/MicroZed-Chronicles
-
Notifications
You must be signed in to change notification settings - Fork 0
/
VHDL_part24.vhd
596 lines (537 loc) · 22.2 KB
/
VHDL_part24.vhd
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
-- /*Copyright (c) 2015, Adam Taylor
-- All rights reserved.
-- Redistribution and use in source and binary forms, with or without
-- modification, are permitted provided that the following conditions are met:
-- 1. Redistributions of source code must retain the above copyright notice, this
-- list of conditions and the following disclaimer.
-- 2. Redistributions in binary form must reproduce the above copyright notice,
-- this list of conditions and the following disclaimer in the documentation
-- and/or other materials provided with the distribution.
-- THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
-- ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
-- WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
-- DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER 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.
-- The views and conclusions contained in the software and documentation are those
-- of the authors and should not be interpreted as representing official policies,
-- either expressed or implied, of the FreeBSD Project*/
library ieee;
use ieee.std_logic_1164.all;
use ieee.numeric_std.all;
entity Adams_Perihperal_v1_0 is
generic (
-- Users to add parameters here
-- User parameters ends
-- Do not modify the parameters beyond this line
-- Parameters of Axi Slave Bus Interface S00_AXI
C_S00_AXI_DATA_WIDTH : integer := 32;
C_S00_AXI_ADDR_WIDTH : integer := 4
);
port (
-- Users to add ports here
interrupt : out std_logic;
-- User ports ends
-- Do not modify the ports beyond this line
-- Ports of Axi Slave Bus Interface S00_AXI
s00_axi_aclk : in std_logic;
s00_axi_aresetn : in std_logic;
s00_axi_awaddr : in std_logic_vector(C_S00_AXI_ADDR_WIDTH-1 downto 0);
s00_axi_awprot : in std_logic_vector(2 downto 0);
s00_axi_awvalid : in std_logic;
s00_axi_awready : out std_logic;
s00_axi_wdata : in std_logic_vector(C_S00_AXI_DATA_WIDTH-1 downto 0);
s00_axi_wstrb : in std_logic_vector((C_S00_AXI_DATA_WIDTH/8)-1 downto 0);
s00_axi_wvalid : in std_logic;
s00_axi_wready : out std_logic;
s00_axi_bresp : out std_logic_vector(1 downto 0);
s00_axi_bvalid : out std_logic;
s00_axi_bready : in std_logic;
s00_axi_araddr : in std_logic_vector(C_S00_AXI_ADDR_WIDTH-1 downto 0);
s00_axi_arprot : in std_logic_vector(2 downto 0);
s00_axi_arvalid : in std_logic;
s00_axi_arready : out std_logic;
s00_axi_rdata : out std_logic_vector(C_S00_AXI_DATA_WIDTH-1 downto 0);
s00_axi_rresp : out std_logic_vector(1 downto 0);
s00_axi_rvalid : out std_logic;
s00_axi_rready : in std_logic
);
end Adams_Perihperal_v1_0;
architecture arch_imp of Adams_Perihperal_v1_0 is
-- component declaration
component Adams_Perihperal_v1_0_S00_AXI is
generic (
C_S_AXI_DATA_WIDTH : integer := 32;
C_S_AXI_ADDR_WIDTH : integer := 4
);
port (
-- Adam Interface
Reg0 : OUT std_logic_vector(C_S_AXI_DATA_WIDTH-1 downto 0);
Reg1 : OUT std_logic_vector(C_S_AXI_DATA_WIDTH-1 downto 0);
Reg2 : OUT std_logic_vector(C_S_AXI_DATA_WIDTH-1 downto 0);
Reg3 : IN std_logic_vector(C_S_AXI_DATA_WIDTH-1 downto 0);
-- AXI Interface
S_AXI_ACLK : in std_logic;
S_AXI_ARESETN : in std_logic;
S_AXI_AWADDR : in std_logic_vector(C_S_AXI_ADDR_WIDTH-1 downto 0);
S_AXI_AWPROT : in std_logic_vector(2 downto 0);
S_AXI_AWVALID : in std_logic;
S_AXI_AWREADY : out std_logic;
S_AXI_WDATA : in std_logic_vector(C_S_AXI_DATA_WIDTH-1 downto 0);
S_AXI_WSTRB : in std_logic_vector((C_S_AXI_DATA_WIDTH/8)-1 downto 0);
S_AXI_WVALID : in std_logic;
S_AXI_WREADY : out std_logic;
S_AXI_BRESP : out std_logic_vector(1 downto 0);
S_AXI_BVALID : out std_logic;
S_AXI_BREADY : in std_logic;
S_AXI_ARADDR : in std_logic_vector(C_S_AXI_ADDR_WIDTH-1 downto 0);
S_AXI_ARPROT : in std_logic_vector(2 downto 0);
S_AXI_ARVALID : in std_logic;
S_AXI_ARREADY : out std_logic;
S_AXI_RDATA : out std_logic_vector(C_S_AXI_DATA_WIDTH-1 downto 0);
S_AXI_RRESP : out std_logic_vector(1 downto 0);
S_AXI_RVALID : out std_logic;
S_AXI_RREADY : in std_logic
);
end component Adams_Perihperal_v1_0_S00_AXI;
CONSTANT c : signed(16 DOWNTO 0) := to_signed(-577,17);
CONSTANT b : signed(16 DOWNTO 0) := to_signed(57910,17);
CONSTANT a : signed(16 DOWNTO 0) := to_signed(33610,17);
SIGNAL squared : signed(33 DOWNTO 0); -- register holds input squared.
SIGNAL cx2 : signed(50 DOWNTO 0); --register used to hold Cx2
SIGNAL bx : signed(33 DOWNTO 0); -- register used to hold bx
SIGNAL res_int : signed(16 DOWNTO 0); --register holding the temporary result
SIGNAL result : std_logic_vector(31 DOWNTO 0);
SIGNAL reg0 : std_logic_vector(31 DOWNTO 0);
SIGNAL reg1 : std_logic_vector(31 DOWNTO 0);
SIGNAL reg2 : std_logic_vector(31 DOWNTO 0);
SIGNAL reg3 : std_logic_vector(31 DOWNTO 0):=(OTHERS=>'0');
begin
-- Instantiation of Axi Bus Interface S00_AXI
Adams_Perihperal_v1_0_S00_AXI_inst : Adams_Perihperal_v1_0_S00_AXI
generic map (
C_S_AXI_DATA_WIDTH => C_S00_AXI_DATA_WIDTH,
C_S_AXI_ADDR_WIDTH => C_S00_AXI_ADDR_WIDTH
)
port map (
reg0 => reg0,
reg1 => reg1,
reg2 => reg2,
reg3 => reg3,
S_AXI_ACLK => s00_axi_aclk,
S_AXI_ARESETN => s00_axi_aresetn,
S_AXI_AWADDR => s00_axi_awaddr,
S_AXI_AWPROT => s00_axi_awprot,
S_AXI_AWVALID => s00_axi_awvalid,
S_AXI_AWREADY => s00_axi_awready,
S_AXI_WDATA => s00_axi_wdata,
S_AXI_WSTRB => s00_axi_wstrb,
S_AXI_WVALID => s00_axi_wvalid,
S_AXI_WREADY => s00_axi_wready,
S_AXI_BRESP => s00_axi_bresp,
S_AXI_BVALID => s00_axi_bvalid,
S_AXI_BREADY => s00_axi_bready,
S_AXI_ARADDR => s00_axi_araddr,
S_AXI_ARPROT => s00_axi_arprot,
S_AXI_ARVALID => s00_axi_arvalid,
S_AXI_ARREADY => s00_axi_arready,
S_AXI_RDATA => s00_axi_rdata,
S_AXI_RRESP => s00_axi_rresp,
S_AXI_RVALID => s00_axi_rvalid,
S_AXI_RREADY => s00_axi_rready
);
-- Add user logic here
PROCESS(s00_axi_aclk)
BEGIN
IF rising_edge(s00_axi_aclk) THEN
squared <= signed( '0'& reg1(15 DOWNTO 0)) * signed('0'& reg1(15 DOWNTO 0));
cx2 <= (squared * c);
bx <= (signed('0'& reg1(15 DOWNTO 0))* b);
res_int <= a + cx2(48 DOWNTO 32) + ("000"& bx(32 DOWNTO 19));
result(15 downto 0) <= std_logic_vector(res_int(res_int'high -1 DOWNTO 0));
END IF;
END PROCESS;
--PROCESS(s00_axi_aclk)
--BEGIN
-- IF rising_edge(s00_axi_aclk) THEN
-- bx <= (signed('0'& reg1(15 DOWNTO 0))* b);
-- END IF;
--END PROCESS;
interrupt <= '0';
reg3 <= x"0000"& std_logic_vector(result(15 DOWNTO 0));
-- User logic ends
end arch_imp;
File Two Adams_Perihperal_v1_0_S00_AXI.vhd
library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_arith.all;
use ieee.std_logic_unsigned.all;
entity Adams_Perihperal_v1_0_S00_AXI is
generic (
-- Users to add parameters here
-- User parameters ends
-- Do not modify the parameters beyond this line
-- Width of S_AXI data bus
C_S_AXI_DATA_WIDTH : integer := 32;
-- Width of S_AXI address bus
C_S_AXI_ADDR_WIDTH : integer := 4
);
port (
-- Users to add ports here
Reg0 : OUT std_logic_vector(C_S_AXI_DATA_WIDTH-1 downto 0);
Reg1 : OUT std_logic_vector(C_S_AXI_DATA_WIDTH-1 downto 0);
Reg2 : OUT std_logic_vector(C_S_AXI_DATA_WIDTH-1 downto 0);
Reg3 : IN std_logic_vector(C_S_AXI_DATA_WIDTH-1 downto 0);
-- User ports ends
-- Do not modify the ports beyond this line
-- Global Clock Signal
S_AXI_ACLK : in std_logic;
-- Global Reset Signal. This Signal is Active LOW
S_AXI_ARESETN : in std_logic;
-- Write address (issued by master, acceped by Slave)
S_AXI_AWADDR : in std_logic_vector(C_S_AXI_ADDR_WIDTH-1 downto 0);
-- Write channel Protection type. This signal indicates the
-- privilege and security level of the transaction, and whether
-- the transaction is a data access or an instruction access.
S_AXI_AWPROT : in std_logic_vector(2 downto 0);
-- Write address valid. This signal indicates that the master signaling
-- valid write address and control information.
S_AXI_AWVALID : in std_logic;
-- Write address ready. This signal indicates that the slave is ready
-- to accept an address and associated control signals.
S_AXI_AWREADY : out std_logic;
-- Write data (issued by master, acceped by Slave)
S_AXI_WDATA : in std_logic_vector(C_S_AXI_DATA_WIDTH-1 downto 0);
-- Write strobes. This signal indicates which byte lanes hold
-- valid data. There is one write strobe bit for each eight
-- bits of the write data bus.
S_AXI_WSTRB : in std_logic_vector((C_S_AXI_DATA_WIDTH/8)-1 downto 0);
-- Write valid. This signal indicates that valid write
-- data and strobes are available.
S_AXI_WVALID : in std_logic;
-- Write ready. This signal indicates that the slave
-- can accept the write data.
S_AXI_WREADY : out std_logic;
-- Write response. This signal indicates the status
-- of the write transaction.
S_AXI_BRESP : out std_logic_vector(1 downto 0);
-- Write response valid. This signal indicates that the channel
-- is signaling a valid write response.
S_AXI_BVALID : out std_logic;
-- Response ready. This signal indicates that the master
-- can accept a write response.
S_AXI_BREADY : in std_logic;
-- Read address (issued by master, acceped by Slave)
S_AXI_ARADDR : in std_logic_vector(C_S_AXI_ADDR_WIDTH-1 downto 0);
-- Protection type. This signal indicates the privilege
-- and security level of the transaction, and whether the
-- transaction is a data access or an instruction access.
S_AXI_ARPROT : in std_logic_vector(2 downto 0);
-- Read address valid. This signal indicates that the channel
-- is signaling valid read address and control information.
S_AXI_ARVALID : in std_logic;
-- Read address ready. This signal indicates that the slave is
-- ready to accept an address and associated control signals.
S_AXI_ARREADY : out std_logic;
-- Read data (issued by slave)
S_AXI_RDATA : out std_logic_vector(C_S_AXI_DATA_WIDTH-1 downto 0);
-- Read response. This signal indicates the status of the
-- read transfer.
S_AXI_RRESP : out std_logic_vector(1 downto 0);
-- Read valid. This signal indicates that the channel is
-- signaling the required read data.
S_AXI_RVALID : out std_logic;
-- Read ready. This signal indicates that the master can
-- accept the read data and response information.
S_AXI_RREADY : in std_logic
);
end Adams_Perihperal_v1_0_S00_AXI;
architecture arch_imp of Adams_Perihperal_v1_0_S00_AXI is
-- AXI4LITE signals
signal axi_awaddr : std_logic_vector(C_S_AXI_ADDR_WIDTH-1 downto 0);
signal axi_awready : std_logic;
signal axi_wready : std_logic;
signal axi_bresp : std_logic_vector(1 downto 0);
signal axi_bvalid : std_logic;
signal axi_araddr : std_logic_vector(C_S_AXI_ADDR_WIDTH-1 downto 0);
signal axi_arready : std_logic;
signal axi_rdata : std_logic_vector(C_S_AXI_DATA_WIDTH-1 downto 0);
signal axi_rresp : std_logic_vector(1 downto 0);
signal axi_rvalid : std_logic;
-- Example-specific design signals
-- local parameter for addressing 32 bit / 64 bit C_S_AXI_DATA_WIDTH
-- ADDR_LSB is used for addressing 32/64 bit registers/memories
-- ADDR_LSB = 2 for 32 bits (n downto 2)
-- ADDR_LSB = 3 for 64 bits (n downto 3)
constant ADDR_LSB : integer := (C_S_AXI_DATA_WIDTH/32)+ 1;
constant OPT_MEM_ADDR_BITS : integer := 1;
------------------------------------------------
---- Signals for user logic register space example
--------------------------------------------------
---- Number of Slave Registers 4
signal slv_reg0 :std_logic_vector(C_S_AXI_DATA_WIDTH-1 downto 0);
signal slv_reg1 :std_logic_vector(C_S_AXI_DATA_WIDTH-1 downto 0);
signal slv_reg2 :std_logic_vector(C_S_AXI_DATA_WIDTH-1 downto 0);
signal slv_reg3 :std_logic_vector(C_S_AXI_DATA_WIDTH-1 downto 0);
signal slv_reg_rden : std_logic;
signal slv_reg_wren : std_logic;
signal reg_data_out :std_logic_vector(C_S_AXI_DATA_WIDTH-1 downto 0);
signal byte_index : integer;
begin
-- I/O Connections assignments
S_AXI_AWREADY <= axi_awready;
S_AXI_WREADY <= axi_wready;
S_AXI_BRESP <= axi_bresp;
S_AXI_BVALID <= axi_bvalid;
S_AXI_ARREADY <= axi_arready;
S_AXI_RDATA <= axi_rdata;
S_AXI_RRESP <= axi_rresp;
S_AXI_RVALID <= axi_rvalid;
-- Implement axi_awready generation
-- axi_awready is asserted for one S_AXI_ACLK clock cycle when both
-- S_AXI_AWVALID and S_AXI_WVALID are asserted. axi_awready is
-- de-asserted when reset is low.
Reg0 <= slv_reg0;
Reg1 <= slv_reg1;
Reg2 <= slv_reg2;
slv_reg3 <= Reg3;
process (S_AXI_ACLK)
begin
if rising_edge(S_AXI_ACLK) then
if S_AXI_ARESETN = '0' then
axi_awready <= '0';
else
if (axi_awready = '0' and S_AXI_AWVALID = '1' and S_AXI_WVALID = '1') then
-- slave is ready to accept write address when
-- there is a valid write address and write data
-- on the write address and data bus. This design
-- expects no outstanding transactions.
axi_awready <= '1';
else
axi_awready <= '0';
end if;
end if;
end if;
end process;
-- Implement axi_awaddr latching
-- This process is used to latch the address when both
-- S_AXI_AWVALID and S_AXI_WVALID are valid.
process (S_AXI_ACLK)
begin
if rising_edge(S_AXI_ACLK) then
if S_AXI_ARESETN = '0' then
axi_awaddr <= (others => '0');
else
if (axi_awready = '0' and S_AXI_AWVALID = '1' and S_AXI_WVALID = '1') then
-- Write Address latching
axi_awaddr <= S_AXI_AWADDR;
end if;
end if;
end if;
end process;
-- Implement axi_wready generation
-- axi_wready is asserted for one S_AXI_ACLK clock cycle when both
-- S_AXI_AWVALID and S_AXI_WVALID are asserted. axi_wready is
-- de-asserted when reset is low.
process (S_AXI_ACLK)
begin
if rising_edge(S_AXI_ACLK) then
if S_AXI_ARESETN = '0' then
axi_wready <= '0';
else
if (axi_wready = '0' and S_AXI_WVALID = '1' and S_AXI_AWVALID = '1') then
-- slave is ready to accept write data when
-- there is a valid write address and write data
-- on the write address and data bus. This design
-- expects no outstanding transactions.
axi_wready <= '1';
else
axi_wready <= '0';
end if;
end if;
end if;
end process;
-- Implement memory mapped register select and write logic generation
-- The write data is accepted and written to memory mapped registers when
-- axi_awready, S_AXI_WVALID, axi_wready and S_AXI_WVALID are asserted. Write strobes are used to
-- select byte enables of slave registers while writing.
-- These registers are cleared when reset (active low) is applied.
-- Slave register write enable is asserted when valid address and data are available
-- and the slave is ready to accept the write address and write data.
slv_reg_wren <= axi_wready and S_AXI_WVALID and axi_awready and S_AXI_AWVALID ;
process (S_AXI_ACLK)
variable loc_addr :std_logic_vector(OPT_MEM_ADDR_BITS downto 0);
begin
if rising_edge(S_AXI_ACLK) then
if S_AXI_ARESETN = '0' then
slv_reg0 <= (others => '0');
slv_reg1 <= (others => '0');
slv_reg2 <= (others => '0');
-- slv_reg3 <= (others => '0');
else
loc_addr := axi_awaddr(ADDR_LSB + OPT_MEM_ADDR_BITS downto ADDR_LSB);
if (slv_reg_wren = '1') then
case loc_addr is
when b"00" =>
for byte_index in 0 to (C_S_AXI_DATA_WIDTH/8-1) loop
if ( S_AXI_WSTRB(byte_index) = '1' ) then
-- Respective byte enables are asserted as per write strobes
-- slave registor 0
slv_reg0(byte_index*8+7 downto byte_index*8) <= S_AXI_WDATA(byte_index*8+7 downto byte_index*8);
end if;
end loop;
when b"01" =>
for byte_index in 0 to (C_S_AXI_DATA_WIDTH/8-1) loop
if ( S_AXI_WSTRB(byte_index) = '1' ) then
-- Respective byte enables are asserted as per write strobes
-- slave registor 1
slv_reg1(byte_index*8+7 downto byte_index*8) <= S_AXI_WDATA(byte_index*8+7 downto byte_index*8);
end if;
end loop;
when b"10" =>
for byte_index in 0 to (C_S_AXI_DATA_WIDTH/8-1) loop
if ( S_AXI_WSTRB(byte_index) = '1' ) then
-- Respective byte enables are asserted as per write strobes
-- slave registor 2
slv_reg2(byte_index*8+7 downto byte_index*8) <= S_AXI_WDATA(byte_index*8+7 downto byte_index*8);
end if;
end loop;
when b"11" =>
for byte_index in 0 to (C_S_AXI_DATA_WIDTH/8-1) loop
if ( S_AXI_WSTRB(byte_index) = '1' ) then
-- Respective byte enables are asserted as per write strobes
-- slave registor 3
-- slv_reg3(byte_index*8+7 downto byte_index*8) <= S_AXI_WDATA(byte_index*8+7 downto byte_index*8);
end if;
end loop;
when others =>
slv_reg0 <= slv_reg0;
slv_reg1 <= slv_reg1;
slv_reg2 <= slv_reg2;
-- slv_reg3 <= slv_reg3;
end case;
end if;
end if;
end if;
end process;
-- Implement write response logic generation
-- The write response and response valid signals are asserted by the slave
-- when axi_wready, S_AXI_WVALID, axi_wready and S_AXI_WVALID are asserted.
-- This marks the acceptance of address and indicates the status of
-- write transaction.
process (S_AXI_ACLK)
begin
if rising_edge(S_AXI_ACLK) then
if S_AXI_ARESETN = '0' then
axi_bvalid <= '0';
axi_bresp <= "00"; --need to work more on the responses
else
if (axi_awready = '1' and S_AXI_AWVALID = '1' and axi_wready = '1' and S_AXI_WVALID = '1' and axi_bvalid = '0' ) then
axi_bvalid <= '1';
axi_bresp <= "00";
elsif (S_AXI_BREADY = '1' and axi_bvalid = '1') then --check if bready is asserted while bvalid is high)
axi_bvalid <= '0'; -- (there is a possibility that bready is always asserted high)
end if;
end if;
end if;
end process;
-- Implement axi_arready generation
-- axi_arready is asserted for one S_AXI_ACLK clock cycle when
-- S_AXI_ARVALID is asserted. axi_awready is
-- de-asserted when reset (active low) is asserted.
-- The read address is also latched when S_AXI_ARVALID is
-- asserted. axi_araddr is reset to zero on reset assertion.
process (S_AXI_ACLK)
begin
if rising_edge(S_AXI_ACLK) then
if S_AXI_ARESETN = '0' then
axi_arready <= '0';
axi_araddr <= (others => '1');
else
if (axi_arready = '0' and S_AXI_ARVALID = '1') then
-- indicates that the slave has acceped the valid read address
axi_arready <= '1';
-- Read Address latching
axi_araddr <= S_AXI_ARADDR;
else
axi_arready <= '0';
end if;
end if;
end if;
end process;
-- Implement axi_arvalid generation
-- axi_rvalid is asserted for one S_AXI_ACLK clock cycle when both
-- S_AXI_ARVALID and axi_arready are asserted. The slave registers
-- data are available on the axi_rdata bus at this instance. The
-- assertion of axi_rvalid marks the validity of read data on the
-- bus and axi_rresp indicates the status of read transaction.axi_rvalid
-- is deasserted on reset (active low). axi_rresp and axi_rdata are
-- cleared to zero on reset (active low).
process (S_AXI_ACLK)
begin
if rising_edge(S_AXI_ACLK) then
if S_AXI_ARESETN = '0' then
axi_rvalid <= '0';
axi_rresp <= "00";
else
if (axi_arready = '1' and S_AXI_ARVALID = '1' and axi_rvalid = '0') then
-- Valid read data is available at the read data bus
axi_rvalid <= '1';
axi_rresp <= "00"; -- 'OKAY' response
elsif (axi_rvalid = '1' and S_AXI_RREADY = '1') then
-- Read data is accepted by the master
axi_rvalid <= '0';
end if;
end if;
end if;
end process;
-- Implement memory mapped register select and read logic generation
-- Slave register read enable is asserted when valid address is available
-- and the slave is ready to accept the read address.
slv_reg_rden <= axi_arready and S_AXI_ARVALID and (not axi_rvalid) ;
process (slv_reg0, slv_reg1, slv_reg2, slv_reg3, axi_araddr, S_AXI_ARESETN, slv_reg_rden)
variable loc_addr :std_logic_vector(OPT_MEM_ADDR_BITS downto 0);
begin
if S_AXI_ARESETN = '0' then
reg_data_out <= (others => '1');
else
-- Address decoding for reading registers
loc_addr := axi_araddr(ADDR_LSB + OPT_MEM_ADDR_BITS downto ADDR_LSB);
case loc_addr is
when b"00" =>
reg_data_out <= slv_reg0;
when b"01" =>
reg_data_out <= slv_reg1;
when b"10" =>
reg_data_out <= slv_reg2;
when b"11" =>
reg_data_out <= slv_reg3;
when others =>
reg_data_out <= (others => '0');
end case;
end if;
end process;
-- Output register or memory read data
process( S_AXI_ACLK ) is
begin
if (rising_edge (S_AXI_ACLK)) then
if ( S_AXI_ARESETN = '0' ) then
axi_rdata <= (others => '0');
else
if (slv_reg_rden = '1') then
-- When there is a valid read address (S_AXI_ARVALID) with
-- acceptance of read address by the slave (axi_arready),
-- output the read dada
-- Read address mux
axi_rdata <= reg_data_out; -- register read data
end if;
end if;
end if;
end process;
-- Add user logic here
-- User logic ends
end arch_imp;