OpenCores
URL https://opencores.org/ocsvn/sdram_controller/sdram_controller/trunk

Subversion Repositories sdram_controller

[/] [sdram_controller/] [trunk/] [sdram_init.vhd] - Blame information for rev 3

Go to most recent revision | Details | Compare with Previous | View Log

Line No. Rev Author Line
1 2 lynn0p
----------------------------------------------------------------------------------
2
-- Company: OPL Aerospatiale AG
3
-- Engineer: Owen Lynn <lynn0p@hotmail.com>
4
-- 
5
-- Create Date:    17:29:55 08/29/2009 
6
-- Design Name: 
7
-- Module Name:    sdram_init - impl 
8
-- Project Name: 
9
-- Target Devices: 
10
-- Tool versions: 
11
-- Description: This is the FSM that gets the DDR SDRAM chip past init. Otherwise
12
--  the main FSM would grow pretty unwieldy and unstable.
13
--
14
-- Dependencies: 
15
--
16
-- Revision: 
17
-- Revision 0.01 - File Created
18
-- Additional Comments: 
19
--  Copyright (c) 2009 Owen Lynn <lynn0p@hotmail.com>
20
--  Released under the GNU Lesser General Public License, Version 3
21
--
22
----------------------------------------------------------------------------------
23
library IEEE;
24
use IEEE.STD_LOGIC_1164.ALL;
25
use IEEE.STD_LOGIC_ARITH.ALL;
26
use IEEE.STD_LOGIC_UNSIGNED.ALL;
27
 
28
---- Uncomment the following library declaration if instantiating
29
---- any Xilinx primitives in this code.
30
--library UNISIM;
31
--use UNISIM.VComponents.all;
32
 
33
entity sdram_init is
34
        port(
35
                clk_000 : in std_logic;
36
                reset   : in std_logic;
37
 
38
                clke  : out std_logic;
39
                cmd   : out std_logic_vector(2 downto 0);
40
                bank  : out std_logic_vector(1 downto 0);
41
                addr  : out std_logic_vector(12 downto 0);
42
                done  : out std_logic
43
        );
44
end sdram_init;
45
 
46
architecture impl of sdram_init is
47
        component wait_counter is
48
                generic(
49
                        BITS : integer;
50
                        CLKS : integer
51
                );
52
                port(
53
                         clk : in std_logic;
54
                         rst : in std_logic;
55
                        done : out std_logic
56
                );
57
        end component;
58
 
59
        constant CMD_NOP        : std_logic_vector(2 downto 0)  := "111";
60
        constant CMD_PRECHARGE  : std_logic_vector(2 downto 0)  := "010";
61
        constant CMD_AUTO_REFR  : std_logic_vector(2 downto 0)  := "100";
62
        constant CMD_LOAD_MR    : std_logic_vector(2 downto 0)  := "000";
63
 
64
        constant CLKS_200US         : integer := 21000; -- well, it's supposed to be 20000, but i'm fudging with 21000
65
 
66
        type INIT_STATES is ( STATE_START, STATE_WAIT200US, STATE_CLKE, STATE_PRECHARGE_ALL0, STATE_WAIT_PRECHARGE_ALL0, STATE_LOAD_MRE,
67
                              STATE_WAIT_MRE, STATE_LOAD_MRN, STATE_WAIT_MRN, STATE_PRECHARGE_ALL1, STATE_WAIT_PRECHARGE_ALL1, STATE_AUTO_REFRESH0,
68
                                                                 STATE_WAIT_AR_CTR0, STATE_WAIT_AUTO_REFRESH0, STATE_AUTO_REFRESH1, STATE_WAIT_AR_CTR1, STATE_WAIT_AUTO_REFRESH1,
69
                                                                 STATE_WAIT_200_CLOCKS, STATE_DONE );
70
 
71
        signal init_state : INIT_STATES;
72
 
73
        signal wait200us_rst : std_logic;
74
        signal wait200us_done : std_logic;
75
 
76
        signal wait_ar_rst : std_logic;
77
        signal wait_ar_done : std_logic;
78
 
79
        signal wait_200clks_rst : std_logic;
80
        signal wait_200clks_done : std_logic;
81
 
82
        signal a058 : std_logic;
83
        signal a10 : std_logic;
84
        signal bk0 : std_logic;
85
 
86
begin
87
 
88
        WAIT200US_CTR: wait_counter
89
        generic map(
90
                BITS => 16,
91
                CLKS => CLKS_200US
92
        )
93
        port map(
94
                clk => clk_000,
95
                rst => wait200us_rst,
96
                done => wait200us_done
97
        );
98
 
99
        WAIT_AR_CTR: wait_counter
100
        generic map(
101
                BITS => 4,
102
                CLKS => 11
103
        )
104
        port map(
105
                clk => clk_000,
106
                rst => wait_ar_rst,
107
                done => wait_ar_done
108
        );
109
 
110
        WAIT_200CLKS_CTR: wait_counter
111
        generic map(
112
                BITS => 8,
113
                CLKS => 200
114
        )
115
        port map(
116
                clk => clk_000,
117
                rst => wait_200clks_rst,
118
                done => wait_200clks_done
119
        );
120
 
121
        -- really optimized output of FSM
122
        addr(12) <= '0';
123
        addr(11) <= '0';
124
        addr(10) <= a10;
125
        addr(9)  <= '0';
126
        addr(8)  <= a058;
127
        addr(7)  <= '0';
128
        addr(6)  <= '0';
129
        addr(5)  <= a058;
130
        addr(4)  <= '0';
131
        addr(3)  <= '0';
132
        addr(2)  <= '0';
133
        addr(1)  <= '0';
134
        addr(0)  <= a058;
135
        bank(1) <= '0';
136
        bank(0) <= bk0;
137
 
138
        process (clk_000, reset)
139
        begin
140
                if (reset = '1') then
141
                        init_state <= STATE_START;
142
                        wait200us_rst <= '1';
143
                        wait_ar_rst <= '1';
144
                        wait_200clks_rst <= '1';
145
                        clke <= '0';
146
                        cmd <= CMD_NOP;
147
                        bk0 <= '0';
148
                        a10 <= '0'; a058 <= '0';
149
                        done <= '0';
150
                elsif (rising_edge(clk_000)) then
151
                        case init_state is
152
                                when STATE_START =>
153
                                        cmd <= CMD_NOP;
154
                                        bk0 <= '0';
155
                                        a10 <= '0'; a058 <= '0';
156
                                        init_state <= STATE_WAIT200US;
157
 
158
                                when STATE_WAIT200US =>
159
                                        wait200us_rst <= '0';
160
                                        cmd <= CMD_NOP;
161
                                        bk0 <= '0';
162
                                        a10 <= '0'; a058 <= '0';
163
                                        if( wait200us_done = '1' ) then
164
                                                init_state <= STATE_CLKE;
165
                                        else
166
                                                init_state <= init_state;
167
                                        end if;
168
 
169
                                when STATE_CLKE =>
170
                                        clke <= '1';
171
                                        cmd <= CMD_NOP;
172
                                        bk0 <= '0';
173
                                        a10 <= '1'; a058 <= '0'; -- timing kludge
174
                                        init_state <= STATE_PRECHARGE_ALL0;
175
 
176
                                when STATE_PRECHARGE_ALL0 =>
177
                                        cmd <= CMD_PRECHARGE;
178
                                        bk0 <= '0';
179
                                        a10 <= '1'; a058 <= '0';
180
                                        init_state <= STATE_WAIT_PRECHARGE_ALL0;
181
 
182
                                when STATE_WAIT_PRECHARGE_ALL0 =>
183
                                        cmd <= CMD_NOP;
184
                                        bk0 <= '0';
185
                                        a10 <= '0'; a058 <= '0';
186
                                        init_state <= STATE_LOAD_MRE;
187
 
188
                                when STATE_LOAD_MRE =>
189
                                        cmd <= CMD_LOAD_MR;
190
                                        bk0 <= '1';
191
                                        a10 <= '0'; a058 <= '0';
192
                                        init_state <= STATE_WAIT_MRE;
193
 
194
                                when STATE_WAIT_MRE =>
195
                                        cmd <= CMD_NOP;
196
                                        bk0 <= '0';
197
                                        a10 <= '0'; a058 <= '1'; -- timing kludge
198
                                        init_state <= STATE_LOAD_MRN;
199
 
200
                                when STATE_LOAD_MRN =>
201
                                        cmd <= CMD_LOAD_MR;
202
                                        bk0 <= '0';
203
                                        a10 <= '0'; a058 <= '1';
204
                                        init_state <= STATE_WAIT_MRN;
205
 
206
                                when STATE_WAIT_MRN =>
207
                                        cmd <= CMD_NOP;
208
                                        bk0 <= '0';
209
                                        a10 <= '0'; a058 <= '1'; -- timing kludge
210
                                        init_state <= STATE_PRECHARGE_ALL1;
211
 
212
                                when STATE_PRECHARGE_ALL1 =>
213
                                        cmd <= CMD_PRECHARGE;
214
                                        bk0 <= '0';
215
                                        a10 <= '1'; a058 <= '0';
216
                                        init_state <= STATE_WAIT_PRECHARGE_ALL1;
217
 
218
                                when STATE_WAIT_PRECHARGE_ALL1 =>
219
                                        cmd <= CMD_NOP;
220
                                        bk0 <= '0';
221
                                        a10 <= '0'; a058 <= '0';
222
                                        init_state <= STATE_AUTO_REFRESH0;
223
 
224
                                when STATE_AUTO_REFRESH0 =>
225
                                        wait_ar_rst <= '1';
226
                                        cmd <= CMD_AUTO_REFR;
227
                                        bk0 <= '0';
228
                                        a10 <= '0'; a058 <= '0';
229
                                        init_state <= STATE_WAIT_AR_CTR0;
230
 
231
                                when STATE_WAIT_AR_CTR0 =>
232
                                        wait_ar_rst <= '0';
233
                                        cmd <= CMD_NOP;
234
                                        bk0 <= '0';
235
                                        a10 <= '0'; a058 <= '0';
236
                                        init_state <= STATE_WAIT_AUTO_REFRESH0;
237
 
238
                                when STATE_WAIT_AUTO_REFRESH0 =>
239
                                        cmd <= CMD_NOP;
240
                                        bk0 <= '0';
241
                                        a10 <= '0'; a058 <= '0';
242
                                        if (wait_ar_done = '1') then
243
                                                init_state <= STATE_AUTO_REFRESH1;
244
                                        else
245
                                                init_state <= init_state;
246
                                        end if;
247
 
248
                                when STATE_AUTO_REFRESH1 =>
249
                                        wait_ar_rst <= '1';
250
                                        cmd <= CMD_AUTO_REFR;
251
                                        bk0 <= '0';
252
                                        a10 <= '0'; a058 <= '0';
253
                                        init_state <= STATE_WAIT_AR_CTR1;
254
 
255
                                when STATE_WAIT_AR_CTR1 =>
256
                                        wait_ar_rst <= '0';
257
                                        cmd <= CMD_NOP;
258
                                        bk0 <= '0';
259
                                        a10 <= '0'; a058 <= '0';
260
                                        init_state <= STATE_WAIT_AUTO_REFRESH1;
261
 
262
                                when STATE_WAIT_AUTO_REFRESH1 =>
263
                                        wait_200clks_rst <= '1';
264
                                        cmd <= CMD_NOP;
265
                                        bk0 <= '0';
266
                                        a10 <= '0'; a058 <= '0';
267
                                        if (wait_ar_done = '1') then
268
                                                init_state <= STATE_WAIT_200_CLOCKS;
269
                                        else
270
                                                init_state <= init_state;
271
                                        end if;
272
 
273
                                when STATE_WAIT_200_CLOCKS =>
274
                                        wait_200clks_rst <= '0';
275
                                        cmd <= CMD_NOP;
276
                                        bk0 <= '0';
277
                                        a10 <= '0'; a058 <= '0';
278
                                        if (wait_200clks_done = '1') then
279
                                                init_state <= STATE_DONE;
280
                                        else
281
                                                init_state <= init_state;
282
                                        end if;
283
 
284
                                 when STATE_DONE =>
285
                                        done <= '1';
286
                                        cmd <= CMD_NOP;
287
                                        bk0 <= '0';
288
                                        a10 <= '0'; a058 <= '0';
289
 
290
                                when others =>
291
                                        cmd <= CMD_NOP;
292
                                        bk0 <= '0';
293
                                        a10 <= '0'; a058 <= '0';
294
                        end case;
295
                end if;
296
        end process;
297
end impl;
298
 

powered by: WebSVN 2.1.0

© copyright 1999-2024 OpenCores.org, equivalent to Oliscience, all rights reserved. OpenCores®, registered trademark.