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[/] [ata/] [trunk/] [rtl/] [vhdl/] [ocidec3/] [atahost_dma_actrl.vhd] - Blame information for rev 33

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---------------------------------------------------------------------
----                                                             ----
----  OpenCores IDE Controller                                   ----
----  DMA (single- and multiword) mode access controller         ----
----                                                             ----
----  Author: Richard Herveille                                  ----
----          richard@asics.ws                                   ----
----          www.asics.ws                                       ----
----                                                             ----
---------------------------------------------------------------------
----                                                             ----
---- Copyright (C) 2001, 2002 Richard Herveille                  ----
----                          richard@asics.ws                   ----
----                                                             ----
---- This source file may be used and distributed without        ----
---- restriction provided that this copyright statement is not   ----
---- removed from the file and that any derivative work contains ----
---- the original copyright notice and the associated disclaimer.----
----                                                             ----
----     THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY     ----
---- EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED   ----
---- TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS   ----
---- FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL THE AUTHOR      ----
---- 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.                                 ----
----                                                             ----
---------------------------------------------------------------------
 
-- rev.: 1.0 march 9th, 2001. Initial release
--
--  CVS Log
--
--  $Id: atahost_dma_actrl.vhd,v 1.1 2002-02-18 14:32:12 rherveille Exp $
--
--  $Date: 2002-02-18 14:32:12 $
--  $Revision: 1.1 $
--  $Author: rherveille $
--  $Locker:  $
--  $State: Exp $
--
-- Change History:
--               $Log: not supported by cvs2svn $
--
--
 
 
-- Host accesses to DMA ports are 32bit wide. Accesses are made by 2 consecutive 16bit accesses to the ATA
-- device's DataPort. The MSB HostData(31:16) is transfered first, then the LSB HostData(15:0) is transfered.
 
--
---------------------------
-- DMA Access Controller --
---------------------------
--
library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_arith.all;
 
entity atahost_dma_actrl is
        generic(
                TWIDTH : natural := 8;                     -- counter width
 
                -- DMA mode 0 settings (@100MHz clock)
                DMA_mode0_Tm : natural := 4;               -- 50ns
                DMA_mode0_Td : natural := 21;              -- 215ns
                DMA_mode0_Teoc : natural := 21             -- 215ns ==> T0 - Td - Tm = 480 - 50 - 215 = 215
        );
        port(
                clk : in std_logic;                           -- master clock
                nReset : in std_logic;                        -- asynchronous active low reset
                rst : in std_logic;                           -- synchronous active high reset
 
                IDEctrl_rst : in std_logic;                   -- IDE control register bit0, 'rst'
 
                sel : in std_logic;                           -- DMA buffers selected
                we : in std_logic;                            -- write enable input
                ack : out std_logic;                                    -- acknowledge output
 
                dev0_Tm,
                dev0_Td,
                dev0_Teoc : in unsigned(7 downto 0);          -- DMA mode timing device 0
                dev1_Tm,
                dev1_Td,
                dev1_Teoc : in unsigned(7 downto 0);          -- DMA mode timing device 1
 
                DMActrl_DMAen,
                DMActrl_dir,
                DMActrl_BeLeC0,
                DMActrl_BeLeC1 : in std_logic;                -- control register settings
 
                TxD : in std_logic_vector(31 downto 0);       -- DMA transmit data
                TxFull : buffer std_logic;                    -- DMA transmit buffer full
                RxQ : out std_logic_vector(31 downto 0);      -- DMA receive data
                RxEmpty : buffer std_logic;                   -- DMA receive buffer empty
                RxFull : out std_logic;                       -- DMA receive buffer full
                DMA_req : out std_logic;                      -- DMA request to external DMA engine
                DMA_ack : in std_logic;                       -- DMA acknowledge from external DMA engine
 
                DMARQ : in std_logic;                         -- ATA devices request DMA transfer
 
                SelDev : in std_logic;                        -- Selected device        
 
                Go : in std_logic;                            -- Start transfer sequence
                Done : out std_logic;                         -- Transfer sequence done
 
                DDi : in std_logic_vector(15 downto 0);       -- Data from ATA DD bus
                DDo : out std_logic_vector(15 downto 0);      -- Data towards ATA DD bus
 
                DIOR,
                DIOW : buffer std_logic
        );
end entity atahost_dma_actrl;
 
architecture structural of atahost_dma_actrl is
        --
        -- component declarations
        --
        component atahost_dma_tctrl is
        generic(
                TWIDTH : natural := 8;            -- counter width
 
                -- DMA mode 0 settings (@100MHz clock)
                DMA_mode0_Tm : natural := 6;     -- 70ns
                DMA_mode0_Td : natural := 28;    -- 290ns
                DMA_mode0_Teoc : natural := 23   -- 240ns ==> T0 - T1 - T2 = 600 - 70 - 290 = 240
        );
        port(
                clk : in std_logic;                      -- master clock
                nReset : in std_logic;                   -- asynchronous active low reset
                rst : in std_logic;                      -- synchronous active high reset
 
                -- timing register settings
                Tm : in unsigned(TWIDTH -1 downto 0);    -- Tm time (in clk-ticks)
                Td : in unsigned(TWIDTH -1 downto 0);    -- Td time (in clk-ticks)
                Teoc : in unsigned(TWIDTH -1 downto 0);  -- end of cycle time
 
                -- control signals
                go : in std_logic;                       -- DMA controller selected (strobe signal)
                we : in std_logic;                       -- DMA direction '1' = write, '0' = read
 
                -- return signals
                done : out std_logic;                    -- finished cycle
                dstrb : out std_logic;                   -- data strobe
 
                -- ATA signals
                DIOR,                                    -- IOread signal, active high
                DIOW : buffer std_logic                  -- IOwrite signal, active high
        );
        end component atahost_dma_tctrl;
 
        component atahost_reg_buf is
        generic (
                WIDTH : natural := 8
        );
        port(
                clk : in std_logic;
                nReset : in std_logic;
                rst : in std_logic;
 
                D : in std_logic_vector(WIDTH -1 downto 0);
                Q : out std_logic_vector(WIDTH -1 downto 0);
                rd : in std_logic;
                wr : in std_logic;
                valid : buffer std_logic
        );
        end component atahost_reg_buf;
 
        component atahost_fifo is
        generic(
                DEPTH : natural := 32;                      -- fifo depth
                SIZE : natural := 32                        -- data width
        );
        port(
                clk : in std_logic;                         -- master clock in
                nReset : in std_logic := '1';               -- asynchronous active low reset
                rst : in std_logic := '0';                  -- synchronous active high reset
 
                rreq : in std_logic;                        -- read request
                wreq : in std_logic;                        -- write request
 
                empty : out std_logic;                      -- fifo empty
                full : out std_logic;                       -- fifo full
 
                D : in std_logic_vector(SIZE -1 downto 0);  -- data input
                Q : out std_logic_vector(SIZE -1 downto 0)  -- data output
        );
        end component atahost_fifo;
 
        signal Tdone, Tfw : std_logic;
        signal RxWr, TxRd : std_logic;
        signal dstrb, rd_dstrb, wr_dstrb : std_logic;
        signal TxbufQ, RxbufD : std_logic_vector(31 downto 0);
 
begin
 
        -- note: *fw = *first_word, *lw = *last_word
 
 
        --
        -- generate DDi/DDo controls
        --
        gen_DMA_sigs: block
                signal writeDfw, writeDlw : std_logic_vector(15 downto 0);
                signal readDfw, readDlw : std_logic_vector(15 downto 0);
                signal BeLeC : std_logic; -- BigEndian <-> LittleEndian conversion
        begin
                -- generate byte_swap signal
                BeLeC <=        (not SelDev and DMActrl_BeLeC0) or (SelDev and DMActrl_BeLeC1);
 
                -- generate Tfw (Transfering first word)
                gen_Tfw: process(clk, nReset)
                begin
                        if (nReset = '0') then
                                Tfw <= '0';
                        elsif (clk'event and clk = '1') then
                                if (rst = '1') then
                                        Tfw <= '0';
                                else
                                        Tfw <= go or (Tfw and not Tdone);
                                end if;
                        end if;
                end process gen_Tfw;
 
                -- transmit data part
                gen_writed_pipe:process(clk)
                begin
                        if (clk'event and clk = '1') then
                                if (TxRd = '1') then                              -- reload registers
                                        if (BeLeC = '1') then                           -- Do big<->little endian conversion
                                                writeDfw(15 downto 8) <= TxbufQ( 7 downto  0); -- TxbufQ = data from transmit buffer
                                                writeDfw( 7 downto 0) <= TxbufQ(15 downto  8);
                                                writeDlw(15 downto 8) <= TxbufQ(23 downto 16);
                                                writeDlw( 7 downto 0) <= TxbufQ(31 downto 24);
                                        else                                              -- don't do big<->little endian conversion
                                                writeDfw <= TxbufQ(31 downto 16);
                                                writeDlw <= TxbufQ(15 downto 0);
                                        end if;
                                elsif (wr_dstrb = '1') then                          -- next word to transfer
                                        writeDfw <= writeDlw;
                                end if;
                        end if;
                end process gen_writed_pipe;
                DDo <= writeDfw;                                       -- assign DMA data out
 
                -- generate transmit register read request
                gen_Tx_rreq: process(clk, nReset)
                begin
                        if (nReset = '0') then
                                TxRd <= '0';
                        elsif (clk'event and clk = '1') then
                                if (rst = '1') then
                                        TxRd <= '0';
                                else
                                        TxRd <= go and DMActrl_dir;
                                end if;
                        end if;
                end process gen_Tx_rreq;
 
                -- receive
                gen_readd_pipe:process(clk)
                begin
                        if (clk'event and clk = '1') then
                                if (rd_dstrb = '1') then
 
                                        readDfw <= readDlw;                   -- shift previous read word to msb
                                        if (BeLeC = '1') then                 -- swap bytes
                                                readDlw(15 downto 8) <= DDi( 7 downto 0);
                                                readDlw( 7 downto 0) <= DDi(15 downto 8);
                                        else                                  -- don't swap bytes
                                                readDlw <= DDi;
                                        end if;
                                end if;
                        end if;
                end process gen_readd_pipe;
                -- RxD = data to receive buffer
                RxbufD <= (readDfw & readDlw) when (BeLeC = '0') else (readDlw & readDfw);
 
                -- generate receive register write request
                gen_Rx_wreq: process(clk, nReset)
                begin
                        if (nReset = '0') then
                                RxWr <= '0';
                        elsif (clk'event and clk = '1') then
                                if (rst = '1') then
                                        RxWr <= '0';
                                else
                                        RxWr <= not Tfw and rd_dstrb;
                                end if;
                        end if;
                end process gen_Rx_wreq;
        end block gen_DMA_sigs;
 
 
        --
        -- Hookup DMA read / write buffers
        --
        gen_DMAbuf: block
                signal DMArst : std_logic;
                signal RxRd, TxWr : std_logic;
                signal iRxEmpty : std_logic;
        begin
                -- generate DMA reset signal
                DMArst <= rst or IDEctrl_rst;
 
                Txbuf: atahost_reg_buf
                        generic map (WIDTH => 32)
                        port map (
                                clk    => clk,
                                nReset => nReset,
                                rst    => DMArst,
                                D      => TxD,
                                Q      => TxbufQ,
                                rd     => TxRd,
                                wr     => TxWr,
                                valid  =>       TxFull
                        );
 
                Rxbuf: atahost_fifo
                        generic map (DEPTH => 7, SIZE => 32)
                        port map (
                                clk    => clk,
                                nReset => nReset,
                                rst    => DMArst,
                                D      => RxbufD,
                                Q      => RxQ,
                                rreq   => RxRd,
                                wreq   => RxWr,
                                empty  =>       iRxEmpty,
                                full   => RxFull
                        );
 
                RxEmpty <= iRxEmpty; -- avoid 'cannot associate OUT port with BUFFER port' error
 
                --
                -- generate DMA buffer access signals
                --
                RxRd <= sel and not we and not RxEmpty;
                TxWr <= sel and     we and not TxFull;
 
                ack  <= RxRd or TxWr; -- DMA buffer access acknowledge
        end block gen_DMAbuf;
 
        --
        -- generate request signal for external DMA engine
        --
        gen_DMA_req: block
                signal hgo : std_logic;
                signal iDMA_req : std_logic;
                signal request : std_logic;
        begin
                -- generate hold-go
                gen_hgo : process(clk, nReset)
                begin
                        if (nReset = '0') then
                                hgo <= '0';
                        elsif (clk'event and clk = '1') then
                                if (rst = '1') then
                                        hgo <= '0';
                                else
                                        hgo <= go or (hgo and not (wr_dstrb and not Tfw) and DMActrl_dir);
                                end if;
                        end if;
                end process gen_hgo;
 
                request <= (DMActrl_dir and DMARQ and not TxFull and not hgo) or not RxEmpty;
                process(clk, nReset)
                begin
                        if (nReset = '0') then
                                iDMA_req <= '0';
                        elsif (clk'event and clk = '1') then
                                if (rst = '1') then
                                        iDMA_req <= '0';
                                else
                                        iDMA_req <= DMActrl_DMAen and not DMA_ack and (request or iDMA_req);
--                              DMA_req <= (DMActrl_DMAen and DMActrl_dir and DMARQ and not TxFull and not hgo) or not RxEmpty;
                                end if;
                        end if;
                end process;
                DMA_req <= iDMA_req;
        end block gen_DMA_req;
 
 
        --
        -- DMA timing controller
        --
        DMA_timing_ctrl: block
                signal Tm, Td, Teoc, Tdmack_ext : unsigned(TWIDTH -1 downto 0);
                signal dTfw, igo : std_logic;
        begin
                --
                -- generate internal GO signal
                --
                gen_igo : process(clk, nReset)
                begin
                        if (nReset = '0') then
                                igo  <= '0';
                                dTfw <= '0';
                        elsif (clk'event and clk = '1') then
                                if (rst = '1') then
                                        igo  <= '0';
                                        dTfw <= '0';
                                else
                                        igo  <= go or (not Tfw and dTfw);
                                        dTfw <= Tfw;
                                end if;
                        end if;
                end process gen_igo;
 
                --
                -- select timing settings for the addressed device
                --
                sel_dev_t: process(clk)
                begin
                        if (clk'event and clk = '1') then
                                if (SelDev = '1') then                      -- device1 selected
                                        Tm   <= dev1_Tm;
                                        Td   <= dev1_Td;
                                        Teoc <= dev1_Teoc;
                                else                                        -- device0 selected
                                        Tm   <= dev0_Tm;
                                        Td   <= dev0_Td;
                                        Teoc <= dev0_Teoc;
                                end if;
                        end if;
                end process sel_dev_t;
 
                --
                -- hookup timing controller
                --
                DMA_timing_ctrl: atahost_dma_tctrl
                        generic map (
                                TWIDTH => TWIDTH,
                                DMA_mode0_Tm   => DMA_mode0_Tm,
                                DMA_mode0_Td   => DMA_mode0_Td,
                                DMA_mode0_Teoc => DMA_mode0_Teoc
                        )
                        port map (
                                clk    => clk,
                                nReset => nReset,
                                rst    => rst,
                                Tm     => Tm,
                                Td     => Td,
                                Teoc   => Teoc,
                                go     => igo,
                                we     => DMActrl_dir,
                                done   => Tdone,
                                dstrb  => dstrb,
                                DIOR   => dior,
                                DIOW   => diow
                        );
 
                done <= Tdone and not Tfw;             -- done transfering last word
                rd_dstrb <= dstrb and not DMActrl_dir; -- read data strobe
                wr_dstrb <= dstrb and     DMActrl_dir; -- write data strobe
        end block DMA_timing_ctrl;
 
end architecture structural;
 

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[/] [ata/] [trunk/] [rtl/] [vhdl/] [ocidec3/] [atahost_dma_actrl.vhd] - Blame information for rev 33

Line No.	Rev	Author	Line
1	27	rherveille	`---------------------------------------------------------------------`
2			`---- ----`
3			`---- OpenCores IDE Controller ----`
4			`---- DMA (single- and multiword) mode access controller ----`
5			`---- ----`
6			`---- Author: Richard Herveille ----`
7			`---- richard@asics.ws ----`
8			`---- www.asics.ws ----`
9			`---- ----`
10			`---------------------------------------------------------------------`
11			`---- ----`
12			`---- Copyright (C) 2001, 2002 Richard Herveille ----`
13			`---- richard@asics.ws ----`
14			`---- ----`
15			`---- This source file may be used and distributed without ----`
16			`---- restriction provided that this copyright statement is not ----`
17			`---- removed from the file and that any derivative work contains ----`
18			`---- the original copyright notice and the associated disclaimer.----`
19			`---- ----`
20			---- THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY ----
21			`---- EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED ----`
22			`---- TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS ----`
23			`---- FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL THE AUTHOR ----`
24			`---- OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, ----`
25			`---- INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES ----`
26			`---- (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE ----`
27			`---- GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR ----`
28			`---- BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF ----`
29			`---- LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT ----`
30			`---- (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT ----`
31			`---- OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE ----`
32			`---- POSSIBILITY OF SUCH DAMAGE. ----`
33			`---- ----`
34			`---------------------------------------------------------------------`
35
36			`-- rev.: 1.0 march 9th, 2001. Initial release`
37			`--`
38			`-- CVS Log`
39			`--`
40			`-- $Id: atahost_dma_actrl.vhd,v 1.1 2002-02-18 14:32:12 rherveille Exp $`
41			`--`
42			`-- $Date: 2002-02-18 14:32:12 $`
43			`-- $Revision: 1.1 $`
44			`-- $Author: rherveille $`
45			`-- $Locker: $`
46			`-- $State: Exp $`
47			`--`
48			`-- Change History:`
49			`-- $Log: not supported by cvs2svn $`
50			`--`
51			`--`
52
53
54			`-- Host accesses to DMA ports are 32bit wide. Accesses are made by 2 consecutive 16bit accesses to the ATA`
55			`-- device's DataPort. The MSB HostData(31:16) is transfered first, then the LSB HostData(15:0) is transfered.`
56
57			`--`
58			`---------------------------`
59			`-- DMA Access Controller --`
60			`---------------------------`
61			`--`
62			`library ieee;`
63			`use ieee.std_logic_1164.all;`
64			`use ieee.std_logic_arith.all;`
65
66			`entity atahost_dma_actrl is`
67			`generic(`
68			`TWIDTH : natural := 8; -- counter width`
69
70			`-- DMA mode 0 settings (@100MHz clock)`
71			`DMA_mode0_Tm : natural := 4; -- 50ns`
72			`DMA_mode0_Td : natural := 21; -- 215ns`
73			`DMA_mode0_Teoc : natural := 21 -- 215ns ==> T0 - Td - Tm = 480 - 50 - 215 = 215`
74			`);`
75			`port(`
76			`clk : in std_logic; -- master clock`
77			`nReset : in std_logic; -- asynchronous active low reset`
78			`rst : in std_logic; -- synchronous active high reset`
79
80			`IDEctrl_rst : in std_logic; -- IDE control register bit0, 'rst'`
81
82			`sel : in std_logic; -- DMA buffers selected`
83			`we : in std_logic; -- write enable input`
84			`ack : out std_logic; -- acknowledge output`
85
86			`dev0_Tm,`
87			`dev0_Td,`
88			`dev0_Teoc : in unsigned(7 downto 0); -- DMA mode timing device 0`
89			`dev1_Tm,`
90			`dev1_Td,`
91			`dev1_Teoc : in unsigned(7 downto 0); -- DMA mode timing device 1`
92
93			`DMActrl_DMAen,`
94			`DMActrl_dir,`
95			`DMActrl_BeLeC0,`
96			`DMActrl_BeLeC1 : in std_logic; -- control register settings`
97
98			`TxD : in std_logic_vector(31 downto 0); -- DMA transmit data`
99			`TxFull : buffer std_logic; -- DMA transmit buffer full`
100			`RxQ : out std_logic_vector(31 downto 0); -- DMA receive data`
101			`RxEmpty : buffer std_logic; -- DMA receive buffer empty`
102			`RxFull : out std_logic; -- DMA receive buffer full`
103			`DMA_req : out std_logic; -- DMA request to external DMA engine`
104			`DMA_ack : in std_logic; -- DMA acknowledge from external DMA engine`
105
106			`DMARQ : in std_logic; -- ATA devices request DMA transfer`
107
108			`SelDev : in std_logic; -- Selected device`
109
110			`Go : in std_logic; -- Start transfer sequence`
111			`Done : out std_logic; -- Transfer sequence done`
112
113			`DDi : in std_logic_vector(15 downto 0); -- Data from ATA DD bus`
114			`DDo : out std_logic_vector(15 downto 0); -- Data towards ATA DD bus`
115
116			`DIOR,`
117			`DIOW : buffer std_logic`
118			`);`
119			`end entity atahost_dma_actrl;`
120
121			`architecture structural of atahost_dma_actrl is`
122			`--`
123			`-- component declarations`
124			`--`
125			`component atahost_dma_tctrl is`
126			`generic(`
127			`TWIDTH : natural := 8; -- counter width`
128
129			`-- DMA mode 0 settings (@100MHz clock)`
130			`DMA_mode0_Tm : natural := 6; -- 70ns`
131			`DMA_mode0_Td : natural := 28; -- 290ns`
132			`DMA_mode0_Teoc : natural := 23 -- 240ns ==> T0 - T1 - T2 = 600 - 70 - 290 = 240`
133			`);`
134			`port(`
135			`clk : in std_logic; -- master clock`
136			`nReset : in std_logic; -- asynchronous active low reset`
137			`rst : in std_logic; -- synchronous active high reset`
138
139			`-- timing register settings`
140			`Tm : in unsigned(TWIDTH -1 downto 0); -- Tm time (in clk-ticks)`
141			`Td : in unsigned(TWIDTH -1 downto 0); -- Td time (in clk-ticks)`
142			`Teoc : in unsigned(TWIDTH -1 downto 0); -- end of cycle time`
143
144			`-- control signals`
145			`go : in std_logic; -- DMA controller selected (strobe signal)`
146			`we : in std_logic; -- DMA direction '1' = write, '0' = read`
147
148			`-- return signals`
149			`done : out std_logic; -- finished cycle`
150			`dstrb : out std_logic; -- data strobe`
151
152			`-- ATA signals`
153			`DIOR, -- IOread signal, active high`
154			`DIOW : buffer std_logic -- IOwrite signal, active high`
155			`);`
156			`end component atahost_dma_tctrl;`
157
158			`component atahost_reg_buf is`
159			`generic (`
160			`WIDTH : natural := 8`
161			`);`
162			`port(`
163			`clk : in std_logic;`
164			`nReset : in std_logic;`
165			`rst : in std_logic;`
166
167			`D : in std_logic_vector(WIDTH -1 downto 0);`
168			`Q : out std_logic_vector(WIDTH -1 downto 0);`
169			`rd : in std_logic;`
170			`wr : in std_logic;`
171			`valid : buffer std_logic`
172			`);`
173			`end component atahost_reg_buf;`
174
175			`component atahost_fifo is`
176			`generic(`
177			`DEPTH : natural := 32; -- fifo depth`
178			`SIZE : natural := 32 -- data width`
179			`);`
180			`port(`
181			`clk : in std_logic; -- master clock in`
182			`nReset : in std_logic := '1'; -- asynchronous active low reset`
183			`rst : in std_logic := '0'; -- synchronous active high reset`
184
185			`rreq : in std_logic; -- read request`
186			`wreq : in std_logic; -- write request`
187
188			`empty : out std_logic; -- fifo empty`
189			`full : out std_logic; -- fifo full`
190
191			`D : in std_logic_vector(SIZE -1 downto 0); -- data input`
192			`Q : out std_logic_vector(SIZE -1 downto 0) -- data output`
193			`);`
194			`end component atahost_fifo;`
195
196			`signal Tdone, Tfw : std_logic;`
197			`signal RxWr, TxRd : std_logic;`
198			`signal dstrb, rd_dstrb, wr_dstrb : std_logic;`
199			`signal TxbufQ, RxbufD : std_logic_vector(31 downto 0);`
200
201			`begin`
202
203			`-- note: fw = first_word, lw = last_word`
204
205
206			`--`
207			`-- generate DDi/DDo controls`
208			`--`
209			`gen_DMA_sigs: block`
210			`signal writeDfw, writeDlw : std_logic_vector(15 downto 0);`
211			`signal readDfw, readDlw : std_logic_vector(15 downto 0);`
212			`signal BeLeC : std_logic; -- BigEndian <-> LittleEndian conversion`
213			`begin`
214			`-- generate byte_swap signal`
215			`BeLeC <= (not SelDev and DMActrl_BeLeC0) or (SelDev and DMActrl_BeLeC1);`
216
217			`-- generate Tfw (Transfering first word)`
218			`gen_Tfw: process(clk, nReset)`
219			`begin`
220			`if (nReset = '0') then`
221			`Tfw <= '0';`
222			`elsif (clk'event and clk = '1') then`
223			`if (rst = '1') then`
224			`Tfw <= '0';`
225			`else`
226			`Tfw <= go or (Tfw and not Tdone);`
227			`end if;`
228			`end if;`
229			`end process gen_Tfw;`
230
231			`-- transmit data part`
232			`gen_writed_pipe:process(clk)`
233			`begin`
234			`if (clk'event and clk = '1') then`
235			`if (TxRd = '1') then -- reload registers`
236			`if (BeLeC = '1') then -- Do big<->little endian conversion`
237			`writeDfw(15 downto 8) <= TxbufQ( 7 downto 0); -- TxbufQ = data from transmit buffer`
238			`writeDfw( 7 downto 0) <= TxbufQ(15 downto 8);`
239			`writeDlw(15 downto 8) <= TxbufQ(23 downto 16);`
240			`writeDlw( 7 downto 0) <= TxbufQ(31 downto 24);`
241			`else -- don't do big<->little endian conversion`
242			`writeDfw <= TxbufQ(31 downto 16);`
243			`writeDlw <= TxbufQ(15 downto 0);`
244			`end if;`
245			`elsif (wr_dstrb = '1') then -- next word to transfer`
246			`writeDfw <= writeDlw;`
247			`end if;`
248			`end if;`
249			`end process gen_writed_pipe;`
250			`DDo <= writeDfw; -- assign DMA data out`
251
252			`-- generate transmit register read request`
253			`gen_Tx_rreq: process(clk, nReset)`
254			`begin`
255			`if (nReset = '0') then`
256			`TxRd <= '0';`
257			`elsif (clk'event and clk = '1') then`
258			`if (rst = '1') then`
259			`TxRd <= '0';`
260			`else`
261			`TxRd <= go and DMActrl_dir;`
262			`end if;`
263			`end if;`
264			`end process gen_Tx_rreq;`
265
266			`-- receive`
267			`gen_readd_pipe:process(clk)`
268			`begin`
269			`if (clk'event and clk = '1') then`
270			`if (rd_dstrb = '1') then`
271
272			`readDfw <= readDlw; -- shift previous read word to msb`
273			`if (BeLeC = '1') then -- swap bytes`
274			`readDlw(15 downto 8) <= DDi( 7 downto 0);`
275			`readDlw( 7 downto 0) <= DDi(15 downto 8);`
276			`else -- don't swap bytes`
277			`readDlw <= DDi;`
278			`end if;`
279			`end if;`
280			`end if;`
281			`end process gen_readd_pipe;`
282			`-- RxD = data to receive buffer`
283			`RxbufD <= (readDfw & readDlw) when (BeLeC = '0') else (readDlw & readDfw);`
284
285			`-- generate receive register write request`
286			`gen_Rx_wreq: process(clk, nReset)`
287			`begin`
288			`if (nReset = '0') then`
289			`RxWr <= '0';`
290			`elsif (clk'event and clk = '1') then`
291			`if (rst = '1') then`
292			`RxWr <= '0';`
293			`else`
294			`RxWr <= not Tfw and rd_dstrb;`
295			`end if;`
296			`end if;`
297			`end process gen_Rx_wreq;`
298			`end block gen_DMA_sigs;`
299
300
301			`--`
302			`-- Hookup DMA read / write buffers`
303			`--`
304			`gen_DMAbuf: block`
305			`signal DMArst : std_logic;`
306			`signal RxRd, TxWr : std_logic;`
307			`signal iRxEmpty : std_logic;`
308			`begin`
309			`-- generate DMA reset signal`
310			`DMArst <= rst or IDEctrl_rst;`
311
312			`Txbuf: atahost_reg_buf`
313			`generic map (WIDTH => 32)`
314			`port map (`
315			`clk => clk,`
316			`nReset => nReset,`
317			`rst => DMArst,`
318			`D => TxD,`
319			`Q => TxbufQ,`
320			`rd => TxRd,`
321			`wr => TxWr,`
322			`valid => TxFull`
323			`);`
324
325			`Rxbuf: atahost_fifo`
326			`generic map (DEPTH => 7, SIZE => 32)`
327			`port map (`
328			`clk => clk,`
329			`nReset => nReset,`
330			`rst => DMArst,`
331			`D => RxbufD,`
332			`Q => RxQ,`
333			`rreq => RxRd,`
334			`wreq => RxWr,`
335			`empty => iRxEmpty,`
336			`full => RxFull`
337			`);`
338
339			`RxEmpty <= iRxEmpty; -- avoid 'cannot associate OUT port with BUFFER port' error`
340
341			`--`
342			`-- generate DMA buffer access signals`
343			`--`
344			`RxRd <= sel and not we and not RxEmpty;`
345			`TxWr <= sel and we and not TxFull;`
346
347			`ack <= RxRd or TxWr; -- DMA buffer access acknowledge`
348			`end block gen_DMAbuf;`
349
350			`--`
351			`-- generate request signal for external DMA engine`
352			`--`
353			`gen_DMA_req: block`
354			`signal hgo : std_logic;`
355			`signal iDMA_req : std_logic;`
356			`signal request : std_logic;`
357			`begin`
358			`-- generate hold-go`
359			`gen_hgo : process(clk, nReset)`
360			`begin`
361			`if (nReset = '0') then`
362			`hgo <= '0';`
363			`elsif (clk'event and clk = '1') then`
364			`if (rst = '1') then`
365			`hgo <= '0';`
366			`else`
367			`hgo <= go or (hgo and not (wr_dstrb and not Tfw) and DMActrl_dir);`
368			`end if;`
369			`end if;`
370			`end process gen_hgo;`
371
372			`request <= (DMActrl_dir and DMARQ and not TxFull and not hgo) or not RxEmpty;`
373			`process(clk, nReset)`
374			`begin`
375			`if (nReset = '0') then`
376			`iDMA_req <= '0';`
377			`elsif (clk'event and clk = '1') then`
378			`if (rst = '1') then`
379			`iDMA_req <= '0';`
380			`else`
381			`iDMA_req <= DMActrl_DMAen and not DMA_ack and (request or iDMA_req);`
382			`-- DMA_req <= (DMActrl_DMAen and DMActrl_dir and DMARQ and not TxFull and not hgo) or not RxEmpty;`
383			`end if;`
384			`end if;`
385			`end process;`
386			`DMA_req <= iDMA_req;`
387			`end block gen_DMA_req;`
388
389
390			`--`
391			`-- DMA timing controller`
392			`--`
393			`DMA_timing_ctrl: block`
394			`signal Tm, Td, Teoc, Tdmack_ext : unsigned(TWIDTH -1 downto 0);`
395			`signal dTfw, igo : std_logic;`
396			`begin`
397			`--`
398			`-- generate internal GO signal`
399			`--`
400			`gen_igo : process(clk, nReset)`
401			`begin`
402			`if (nReset = '0') then`
403			`igo <= '0';`
404			`dTfw <= '0';`
405			`elsif (clk'event and clk = '1') then`
406			`if (rst = '1') then`
407			`igo <= '0';`
408			`dTfw <= '0';`
409			`else`
410			`igo <= go or (not Tfw and dTfw);`
411			`dTfw <= Tfw;`
412			`end if;`
413			`end if;`
414			`end process gen_igo;`
415
416			`--`
417			`-- select timing settings for the addressed device`
418			`--`
419			`sel_dev_t: process(clk)`
420			`begin`
421			`if (clk'event and clk = '1') then`
422			`if (SelDev = '1') then -- device1 selected`
423			`Tm <= dev1_Tm;`
424			`Td <= dev1_Td;`
425			`Teoc <= dev1_Teoc;`
426			`else -- device0 selected`
427			`Tm <= dev0_Tm;`
428			`Td <= dev0_Td;`
429			`Teoc <= dev0_Teoc;`
430			`end if;`
431			`end if;`
432			`end process sel_dev_t;`
433
434			`--`
435			`-- hookup timing controller`
436			`--`
437			`DMA_timing_ctrl: atahost_dma_tctrl`
438			`generic map (`
439			`TWIDTH => TWIDTH,`
440			`DMA_mode0_Tm => DMA_mode0_Tm,`
441			`DMA_mode0_Td => DMA_mode0_Td,`
442			`DMA_mode0_Teoc => DMA_mode0_Teoc`
443			`)`
444			`port map (`
445			`clk => clk,`
446			`nReset => nReset,`
447			`rst => rst,`
448			`Tm => Tm,`
449			`Td => Td,`
450			`Teoc => Teoc,`
451			`go => igo,`
452			`we => DMActrl_dir,`
453			`done => Tdone,`
454			`dstrb => dstrb,`
455			`DIOR => dior,`
456			`DIOW => diow`
457			`);`
458
459			`done <= Tdone and not Tfw; -- done transfering last word`
460			`rd_dstrb <= dstrb and not DMActrl_dir; -- read data strobe`
461			`wr_dstrb <= dstrb and DMActrl_dir; -- write data strobe`
462			`end block DMA_timing_ctrl;`
463
464			`end architecture structural;`
465