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DMA_ARBITER.vhd

Last change on this file was 15, checked in by rolagamo, 13 years ago

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1	----------------------------------------------------------------------------------
2	-- Company:
3	-- Engineer: KIEGAING EMMANUEL
4	-- GAMOM ROLAND CHRISTIAN
5	--
6	-- Create Date: 04:39:43 05/21/2011
7	-- Design Name:
8	-- Module Name: DMA_ARBITER - Behavioral
9	-- Project Name:
10	-- Target Devices:
11	-- Tool versions:
12	-- Description:
13	-- gestionnaire DMA pour le port secodaire de la RAM true dual port des mémoire
14	-- privée de chaque noeud
15	-- Dependencies:
16	--
17	-- Revision: 09/07/2012
18	-- Revision 1.01 - File Created
19	-- Additional Comments: Ce module pourra être optimisé pour générer les adresses automatiquement
20	-- par le controleur DMA lorsqu'il est sollicité par la périphérie
21	--
22	----------------------------------------------------------------------------------
23	library IEEE;
24	library NocLib;
25	use IEEE.STD_LOGIC_1164.ALL;
26	use IEEE.STD_LOGIC_ARITH.ALL;
27	use IEEE.STD_LOGIC_UNSIGNED.ALL;
28	use IEEE.numeric_std.all;
29	use NocLib.CoreTypes.all;
30	---- Uncomment the following library declaration if instantiating
31	---- any Xilinx primitives in this code.
32	--library UNISIM;
33	--use UNISIM.VComponents.all;
34
35	entity DMA_ARBITER is
36	Port ( dma_rd_request : in STD_LOGIC_VEctor (3 downto 0):=(others=>'0');
37	data_wr_in : in STD_LOGIC_VECTOR (Word-1 downto 0);
38	data_rd_out : out STD_LOGIC_VECTOR (Word-1 downto 0);
39	address_rd : in STD_LOGIC_VECTOR (ADRLEN-1 downto 0); --adresse pour lecture
40	address_wr : in STD_LOGIC_VECTOR (ADRLEN-1 downto 0); -- adresse pour écriture
41	address_out_wr : out STD_LOGIC_VECTOR (ADRLEN-1 downto 0); -- adresse de sortie du DMA Arbiter
42	address_out_rd : out STD_LOGIC_VECTOR (ADRLEN-1 downto 0);
43	ram_en : out STD_LOGIC; --
44	ram_we : out STD_LOGIC;
45	data_wr_mem : out STD_LOGIC_VECTOR (Word-1 downto 0); -- donnée en sortie écriture
46	data_rd_mem : in STD_LOGIC_VECTOR (Word-1 downto 0); -- données en sortie lecture
47	dma_wr_grant : out STD_LOGIC_vector(3 downto 0):=(others=>'0'); -- autorisation d'écriture
48	hold_req : out STD_Logic; --requete vers application
49	hold_ack : in STD_Logic; --autorisation par l'application
50	clk : in std_logic;
51	reset : in std_logic;
52	dma_rd_grant : out STD_LOGIC_vector(3 downto 0):=(others=>'0'); -- autorisation de lecture
53	dma_wr_request : in STD_LOGIC_vector(3 downto 0):=(others=>'0')); -- demande de lecture
54	end DMA_ARBITER;
55
56	architecture Behavioral of DMA_ARBITER is
57	type fsm_states is (idle,wait_ack,arbiter_ack, writing,ReadWrite,reading);-- definition du type etat pour le codage des etats des fsm
58	signal dmac_state : fsm_states;
59
60	signal prio_rd,prio_wr:std_logic_vector(3 downto 0);--vecteur de bits de priorité
61	signal pri_rd,pri_wr : natural range 0 to 3; -- stocke le numéro du module qui a la priorité
62	signal dma_rd_logic : std_logic_vector(3 downto 0):=(others=>'0');
63	signal dma_wr_logic : std_logic_vector(3 downto 0):=(others=>'0');
64	signal dma_req_wr, dma_req_rd : std_logic;
65	signal tmp :std_logic_vector(3 downto 0):="0000";
66
67	begin
68	--==========================================================================
69	---le MUX qui contrôle les adresses est géré à l'extérieur du contrôleur DMA
70	data_rd_out<=data_rd_mem ;
71	data_wr_mem <= data_wr_in;
72	address_out_rd <= address_rd;
73	address_out_wr <= address_wr;
74	--==========================================================================
75
76	--Déterminer si une requête HOLD doit être émise vers l'application pour la libération du
77	--bus mémoire
78	tmp<=(others =>'0');
79
80	--for i in 0 to 3 loop
81	--dma_req_wr<=dma_req_wr or dma_wr_request(i);
82	--loop;
83
84	--for i in 0 to 3 loop
85	-- dma_req_rd<=dma_req_rd or dma_rd_request(i); -- construire le signal request vers l'extérieur
86	--loop;
87	hold_req<=dma_req_rd or dma_req_wr; --envoyer un Hold vers l'application
88
89
90	-- machine à etat du DMAC
91	dmac_process : process(clk)
92	--variable tmp : natural range 0 to 15;
93	variable tmp_rd,tmp_wr: std_logic_vector(3 downto 0);
94	variable req_rd,req_wr : std_logic:='0' ;
95
96	begin
97	if rising_edge(clk) then
98	if reset = '1' then
99	dmac_state<= idle;
100
101	prio_rd <="0001"; -- au debut priorité lecture au premier module
102	prio_wr <="0010"; -- au debut priorité ecriture au deuxième module
103	pri_rd<=0;--index de la priorité
104	pri_wr<=1;
105	req_rd:='0';
106	req_wr:='0';
107	else
108	if req_wr='0' or dma_wr_request="0000" then --tant que le Ctrl DMA est libre alors faire bouger la priorité en écriture
109	case dma_wr_request is
110	when "0001" => pri_wr<=0;
111	prio_wr<="0001";
112	req_wr:='1';
113	dma_req_wr<= '1';
114	dma_wr_logic <="0001";
115	when "0010" => pri_wr<=1;
116	prio_wr<="0010";
117	req_wr:='1';
118	dma_req_wr<= '1';
119	dma_wr_logic <="0010";
120	when "0100" => pri_wr<=2;
121	prio_wr<="0100";
122	req_wr:='1';
123	dma_req_wr<= '1';
124	dma_wr_logic <="0100";
125	when "1000" => pri_wr<=3;
126	prio_wr<="1000";
127	req_wr:='1';
128	dma_req_wr<= '1';
129	dma_wr_logic <="1000";
130
131	when others => tmp_wr:= (dma_wr_request and prio_wr) ;
132	dma_wr_logic <=tmp_wr;
133	req_wr:= not(All_zeros(tmp_wr));
134	dma_req_wr<= not(All_zeros(tmp_wr));
135	-- la priorité est circulaire et décale à chaque coup d'horloge
136	prio_wr<=rol_vec(prio_wr);
137	if pri_wr=3 then
138	pri_wr<=0;
139	Prio_wr<="0001";
140	else
141	pri_wr<=pri_wr+1;
142	end if;
143	end case;
144
145	end if;
146
147	if req_rd='0' or dma_rd_request="0000" then --tant que le Ctrl DMA est libre alors faire bouger la priorité
148	case dma_rd_request is
149	when "0001" => pri_rd<=0;
150	prio_rd<="0001";
151	req_rd:='1';
152	dma_req_rd<= '1';
153	dma_rd_logic<="0001";
154	when "0010" => pri_rd<=1;
155	prio_rd<="0010";
156	req_rd:='1';
157	dma_req_rd<= '1';
158	dma_rd_logic<="0010";
159
160	when "0100" => pri_rd<=2;
161	prio_rd<="0100";
162	req_rd:='1';
163	dma_req_rd<= '1';
164	dma_rd_logic<="0100";
165
166	when "1000" => pri_rd<=3;
167	prio_rd<="1000";
168	req_rd:='1';
169	dma_req_rd<= '1';
170	dma_rd_logic<="1000";
171
172	when others =>
173
174	tmp_rd:= (dma_rd_request and prio_rd) ;
175	dma_rd_logic<=tmp_rd;
176	dma_req_rd<= not (All_Zeros(tmp_rd));
177	req_rd:= not (All_Zeros(tmp_rd));
178
179	-- la priorité est circulaire et décale à chaque coup d'horloge
180	prio_rd<=rol_vec(prio_rd);
181	if pri_rd =3 then
182	pri_rd<=0;
183	prio_rd<="0001";
184	else
185
186	pri_rd<=pri_rd+1;
187	end if;
188	end case;
189
190	end if;
191
192	case dmac_state is
193	when idle => if req_rd='1' or req_wr='1' then
194	dmac_state<=wait_ack;
195	else -- initialiser la priorité
196
197
198	req_rd:='0';
199	dma_req_rd<= '0';
200	dma_rd_logic <="0000";
201
202
203	req_wr:='0';
204	dma_req_wr<= '0';
205	dma_wr_logic <="0000";
206
207	end if;
208	when wait_ack => -- l'application doit autoriser l'utilisation de la RAM par le Core
209	if dma_wr_request(pri_wr) ='1' or dma_rd_request(pri_rd) ='1' then
210	if hold_ack='1' then
211	dmac_state<=arbiter_ack;
212	end if;
213	else
214
215	if dma_wr_request(pri_wr) ='0' then
216	req_wr:='0';-- forcer une nouvelle recherche de priorité
217	end if;
218
219	if dma_rd_request(pri_rd) ='0' then
220	req_rd:='0';
221	end if;
222	dmac_state<=Idle;
223	end if;
224
225
226	when arbiter_ack => if dma_wr_request(pri_wr) ='1' and dma_rd_request(pri_rd) ='1' then --
227	dmac_state <= Readwrite;
228	elsif dma_wr_request(pri_wr) ='0' and dma_rd_request(pri_rd) ='1' then
229	dmac_state <= Reading;
230	elsif dma_wr_request(pri_wr) ='1' and dma_rd_request(pri_rd) ='0' then
231	dmac_state <= Writing;
232	else
233	dmac_state<=Idle;
234	end if;
235
236	when Writing => if dma_wr_request(pri_wr) ='1' then
237	if hold_ack='1' then
238	-- on reste dans cet état
239	if dma_rd_request(pri_rd)='1' then
240	dmac_state<=ReadWrite;
241	else
242	req_rd:='0';
243	end if;
244	else
245	dmac_state<=wait_ack;
246	end if;
247	elsif dma_rd_request(pri_rd) ='1' then
248	dmac_state <= Reading;
249	else
250	dmac_state <= idle;
251	end if;
252
253
254	when ReadWrite => if hold_ack='1' then
255	if dma_wr_request(pri_wr)='1' and dma_rd_request(pri_rd)='1' then
256	dmac_state <= ReadWrite;
257	elsif dma_wr_request(pri_wr)='1' and dma_rd_request(pri_rd)='0' then
258	dmac_state <= Writing;
259	req_rd:='0';
260	elsif dma_wr_request(pri_wr)='0' and dma_rd_request(pri_rd)='1' then
261	dmac_state <= Reading;
262	req_wr:='0';
263	else
264	dmac_state <= Idle;
265	req_rd:='0';req_wr:='0';
266	end if;
267	else
268	if (dma_wr_request(pri_wr)='1') or (dma_rd_request(pri_rd)='1') then
269	dmac_state <= Wait_ack;
270	else
271	dmac_state <= Idle;
272	end if;
273	end if;
274	when Reading =>
275	if dma_rd_request(pri_rd) ='1' then
276	if hold_ack='1' then
277	-- on reste dans cet état
278	if dma_wr_request(pri_wr)='1' then
279	dmac_state<=ReadWrite;
280	else
281	req_wr:='0';
282	end if;
283	else
284	dmac_state<=wait_ack;
285	end if;
286	elsif dma_wr_request(pri_wr) ='1' then
287	dmac_state<=writing;
288	else
289	dmac_state <= idle;
290	end if;
291	when others => dmac_state <= idle;
292	end case;
293	end if;
294	end if;
295	end process;
296	-- action_asociées
297	ol: process(dmac_state, address_rd, address_wr,pri_wr,pri_rd,prio_wr,prio_rd,dma_wr_request,dma_rd_request)
298
299	begin
300	--tester les requêtes DMA en lecture ou en écriture
301
302	case dmac_state is
303	when idle =>
304	ram_en <='0';
305	ram_we <='0';
306	dma_wr_grant <=(others=>'0');
307	dma_rd_grant <=(others=>'0');
308	--address_out_rd <= address_rd;
309	--hold_req<='0';
310	when wait_ack =>
311	ram_en <='0';
312	ram_we <='0';
313	dma_wr_grant<=(others=>'0');
314	dma_rd_grant<=(others=>'0');
315	--address_out_rd <= (others=>'Z');
316	--address_out_wr <= (others=>'Z');
317	--hold_req<='1';
318	when arbiter_ack => --à optimiser pour gagner un cycle
319	ram_en <='1';
320	ram_we <='0';
321	dma_wr_grant<=(others=>'0');
322	dma_rd_grant<=(others=>'0');
323	--address_out_rd <= (others=>'Z');
324	--address_out_wr <= (others=>'Z');
325	when writing => -- ecriture dans la ram
326	ram_en <='1';
327	ram_we <='1';
328	dma_wr_grant<=(others=>'0');
329	dma_wr_grant(pri_wr) <='1';
330	dma_rd_grant <=(others=>'0');
331	--address_out_rd <= (others=>'Z');
332	--address_out_wr <= address_wr;
333	--hold_req<='1';
334
335	when ReadWrite => -- Lecture et écriture simultannée dans la Dual Port RAM
336	ram_en <='1';
337	ram_we <='1';
338	dma_wr_grant<=(others=>'0');
339	dma_wr_grant(pri_wr) <='1';
340	dma_rd_grant<=(others=>'0');
341	dma_rd_grant(pri_rd)<='1';
342
343	--address_out_rd <= address_rd;
344	--address_out_wr <= address_wr;
345	--hold_req<='1';
346	when Reading => -- lecture dans la ram
347	ram_en <='1';
348	ram_we <='0';
349	dma_wr_grant<=(others=>'0');
350	dma_rd_grant<=(others=>'0');
351	dma_rd_grant(pri_rd)<='1';
352
353	--address_out_rd <= address_rd;
354	--address_out_wr <= (others=>'Z');
355	--hold_req<='1';
356	when others =>
357	ram_en <='0';
358	ram_we <='0';
359	dma_wr_grant <=(others=>'0');
360	dma_rd_grant <=(others=>'0');
361	--address_out_rd <= (others=>'Z');
362	--address_out_wr <= (others=>'Z');
363	--hold_req<='0';
364	end case;
365	end process;
366
367
368	end Behavioral;
369

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source: PROJECT_CORE_MPI/CORE_MPI/TRUNK/DMA_ARBITER.vhd

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