ddrsp16a.vhd

free hardware ip core about sparcv8,a soc cpu in vhdl

    ba := genmux(r.cfg.bsize, haddr(29 downto 22)) &
          genmux(r.cfg.bsize, haddr(28 downto 21));

-- generate chip select

    adec := genmux(r.cfg.bsize, haddr(30 downto 23));

    rams := adec & not adec;

-- sdram access FSM

    if r.trfc /= "000" then v.trfc := r.trfc - 1; end if;

    case r.sdstate is
    when sidle =>
      if (startsd = '1') and (r.cfg.command = "000") and (r.cmstate = midle) 
	and (r.istate = finish)
      then
        v.address := raddr; v.ba := ba;
	if ra.acc.hio = '0' then
	  v.sdcsn := not rams(1 downto 0); v.rasn := '0'; v.sdstate := act1; 
	else v.sdstate := ioreg1; end if;
      end if;
      v.waddr := ra.acc.haddr(7 downto 2);
    when act1 =>
      v.rasn := '1'; v.trfc := r.cfg.trfc;
      if r.cfg.trcd = '1' then v.sdstate := act2; else
	v.sdstate := act3; v.hready := ra.acc.hwrite;
      end if;
      v.waddr := ra.acc.haddr(7 downto 2);
    when act2 =>
      v.sdstate := act3; v.hready := ra.acc.hwrite;
    when act3 =>
      v.casn := '0'; 
      v.address := ra.acc.haddr(13 downto 11) & '0' & ra.acc.haddr(10 downto 2) & '0';
      v.dqm := dqm; 
      if ra.acc.hwrite = '1' then
        v.waddr := r.waddr + 1;
	v.sdstate := wr1; v.sdwen := '0'; v.bdrive := '0'; v.qdrive := '1';
        if (r.waddr /= ra.raddr) then v.hready := '1'; end if;
      else v.sdstate := rd1; end if;
    when wr1 =>
      v.sdwen := '1';  v.casn := '1';  v.qdrive := '1';
      v.waddr := r.waddr + 1;
      v.address(8 downto 3) := r.waddr;
      if (r.waddr <= ra.raddr) and (r.waddr /= "000000") and (r.hready = '1') 
      then 
	v.hready := '1';
        if (r.hready = '1') and (r.waddr(1 downto 0) = "00") then
	  v.sdwen := '0'; v.casn := '0';
	end if;
      else
        v.sdstate := wr2;
	v.dqm := (others => '1'); --v.bdrive := '1'; 
        v.startsdold := r.startsd;
      end if;
    when wr2 =>
      v.sdstate := wr3; v.qdrive := '1';
    when wr3 =>
	v.sdstate := wr4a; v.qdrive := '1';
    when wr4a =>
        v.bdrive := '1'; 
	v.rasn := '0'; v.sdwen := '0'; v.sdstate := wr4; v.qdrive := '1';
    when wr4 =>
      v.sdcsn := "11"; v.rasn := '1'; v.sdwen := '1';  v.qdrive := '0';
      v.sdstate := wr5;
    when wr5 =>
      v.sdstate := sidle;
    when rd1 =>
      v.casn := '1'; v.sdstate := rd7;
      if ra.acc.haddr(4 downto 2) = "011" then 
	v.casn := '0'; v.burst := '1'; v.address(5 downto 3) := "100";
      end if;
    when rd7 =>
      v.casn := '1'; v.sdstate := rd2;
      if ra.acc.haddr(4 downto 2) = "010" then 
	v.casn := '0'; v.burst := '1'; v.address(5 downto 3) := "100";
      end if;
    when rd2 =>
      v.casn := '1'; v.sdstate := rd3;
      if ra.acc.haddr(4 downto 2) = "001" then 
	v.casn := '0'; v.burst := '1'; v.address(5 downto 3) := "100";
      end if;
    when rd3 =>
      if fast = 0 then v.startsdold := r.startsd; end if;
      v.sdstate := rd4; v.hready := '1'; v.casn := '1';
      if r.sdwen = '0' then
	v.rasn := '1'; v.sdwen := '1'; v.sdcsn := "11"; v.dqm := (others => '1');
      elsif ra.acc.haddr(4 downto 2) = "000" then 
	v.casn := '0'; v.burst := '1'; v.address(5) := '1';
        v.waddr := v.address(8 downto 3);
      end if;
      if v.hready = '1' then v.waddr := r.waddr + 1; end if;
    when rd4 =>
      v.hready := '1'; v.casn := '1';
      if (r.sdcsn /= "11") and (r.waddr(1 downto 0) = "11") and (r.burst = '1')
      then
	v.burst := '0';
      elsif (r.sdcsn = "11") or (r.waddr(1 downto 0) = "11") then
	v.dqm := (others => '1'); v.burst := '0';
        if fast /= 0 then v.startsdold := r.startsd; end if;
        if (r.sdcsn /= "11") then
	  v.rasn := '0'; v.sdwen := '0'; v.sdstate := rd5;
	else
          if r.cfg.trp = '1' then v.sdstate := rd6; 
	  else v.sdstate := sidle; end if;
        end if;
      end if;
      if v.hready = '1' then v.waddr := r.waddr + 1; end if;
    when rd5 =>
      if r.cfg.trp = '1' then v.sdstate := rd6; 
      else v.sdstate := sidle; end if;
      v.sdcsn := (others => '1'); v.rasn := '1'; v.sdwen := '1'; 
      v.dqm := (others => '1');
    when rd6 =>
      v.sdstate := sidle; v.dqm := (others => '1');
      v.sdcsn := (others => '1'); v.rasn := '1'; v.sdwen := '1';
    when ioreg1 =>
      readdata := regsd; v.sdstate := ioreg2;
      if ra.acc.hwrite = '0' then v.hready := '1'; end if;
    when ioreg2 =>
      readdata := regsd; v.sdstate := sidle;
      writecfg := ra.acc.hwrite; v.startsdold := r.startsd;
    when others =>
      v.sdstate := sidle;
    end case;

-- sdram commands

    case r.cmstate is
    when midle =>
      if r.sdstate = sidle then
        case r.cfg.command is
        when CMD_PRE => -- precharge
	    v.sdcsn := (others => '0'); v.rasn := '0'; v.sdwen := '0';
	    v.address(12) := '1'; v.cmstate := active;
        when CMD_REF => -- auto-refresh
	  v.sdcsn := (others => '0'); v.rasn := '0'; v.casn := '0';
          v.cmstate := active;
        when CMD_EMR => -- load-ext-mode-reg
	    v.sdcsn := (others => '0'); v.rasn := '0'; v.casn := '0'; 
	    v.sdwen := '0'; v.cmstate := active; v.ba := "01";
	    v.address := "00000000000000"; 
        when CMD_LMR => -- load-mode-reg
	    v.sdcsn := (others => '0'); v.rasn := '0'; v.casn := '0'; 
	    v.sdwen := '0'; v.cmstate := active;  v.ba := "00";
	    v.address := "00000" & r.cfg.dllrst & "0" & "01" & "00011";
        when others => null;
        end case;
      end if;
    when active =>
      v.sdcsn := (others => '1'); v.rasn := '1'; v.casn := '1'; 
      v.sdwen := '1'; v.cfg.command := "000";
      v.cmstate := leadout; v.trfc := r.cfg.trfc;
    when others =>
      if r.trfc = "000" then v.cmstate := midle; end if;

    end case;

-- sdram init

    case r.istate is
    when iidle =>
      if r.cfg.renable = '1' then
        v.cfg.cke := '1'; v.cfg.dllrst := '1';
	if r.cfg.cke = '1' then v.istate := pre; v.cfg.command := CMD_PRE; end if;
      end if;
    when pre =>
      if r.cfg.command = "000" then
        v.cfg.command := "11" & r.cfg.dllrst; -- CMD_LMR/CMD_EMR
	if r.cfg.dllrst = '1' then v.istate := emode; else v.istate := lmode; end if;
      end if;
    when emode =>
      if r.cfg.command = "000" then
        v.istate := lmode; v.cfg.command := CMD_LMR;
      end if;
    when lmode =>
      if r.cfg.command = "000" then
	if r.cfg.dllrst = '1' then 
 	  if r.refresh(9 downto 8) = "00" then -- > 200 clocks delay
            v.cfg.command := CMD_PRE; v.istate := ref1;
	  end if;
	else 
	  v.istate := finish; --v.cfg.command := CMD_LMR;
	  v.cfg.refon := '1'; v.cfg.renable := '0';
	end if;
      end if;
    when ref1 =>
      if r.cfg.command = "000" then
        v.cfg.command := CMD_REF; v.cfg.dllrst := '0'; v.istate := ref2; 
      end if;
    when ref2 =>
      if r.cfg.command = "000" then
        v.cfg.command := CMD_REF; v.istate := pre;
      end if;
    when others =>
      if r.cfg.renable = '1' then
        v.istate := iidle; v.cfg.dllrst := '1';
      end if;
    end case;

-- second part of main fsm

    case r.mstate is
    when active =>
      if v.hready = '1' then
	v.mstate := midle;
      end if;
    when others => null;
    end case;

-- sdram refresh counter

    if ((r.cfg.refon = '1') and (r.istate = finish)) or
	(r.cfg.dllrst = '1')
    then 
	v.refresh := r.refresh - 1;
        if (v.refresh(11) and not r.refresh(11))  = '1' then 
	  v.refresh := r.cfg.refresh;
	  if r.cfg.dllrst = '0' then v.cfg.command := "100"; end if;
	end if;
    end if;

-- AHB register access

    if (ra.acc.hio and ra.acc.hwrite and writecfg) = '1' then
      v.cfg.refresh   :=  wdata(11 downto 0); 
      v.cfg.cke       :=  wdata(15); 
      v.cfg.renable   :=  wdata(16); 
      v.cfg.dllrst    :=  wdata(17); 
      v.cfg.command   :=  wdata(20 downto 18); 
      v.cfg.csize     :=  wdata(22 downto 21); 
      v.cfg.bsize     :=  wdata(25 downto 23); 
      v.cfg.trcd      :=  wdata(26); 
      v.cfg.trfc      :=  wdata(29 downto 27); 
      v.cfg.trp       :=  wdata(30); 
      v.cfg.refon     :=  wdata(31); 
    end if;

    v.nbdrive := not v.bdrive; 

    if oepol = 1 then bdrive := r.nbdrive; vbdrive := (others => v.nbdrive);
    else bdrive := r.bdrive; vbdrive := (others => v.bdrive);end if; 
    
-- reset

    if rst = '0' then
      v.sdstate	      := sidle; 
      v.mstate	      := midle; 
      v.istate	      := finish; 
      v.cmstate	      := midle; 
      v.cfg.command   := "000";
      v.cfg.csize     := conv_std_logic_vector(col-9, 2);
      v.cfg.bsize     := conv_std_logic_vector(log2(Mbyte/8), 3);
      if MHz > 100 then v.cfg.trcd :=  '1'; else v.cfg.trcd :=  '0'; end if;
      v.cfg.refon     :=  '0';
      v.cfg.trfc      := conv_std_logic_vector(75*MHz/1000-2, 3);
      v.cfg.refresh   := conv_std_logic_vector(7800*MHz/1000, 12);
      v.refresh       :=  (others => '0');
      if pwron = 1 then v.cfg.renable :=  '1';
      else v.cfg.renable :=  '0'; end if;
      if MHz > 100 then v.cfg.trp := '1'; else v.cfg.trp := '0'; end if;
      v.dqm	      := (others => '1');
      v.sdwen	      := '1';
      v.rasn	      := '1';
      v.casn	      := '1';
      v.hready	      := '0';
      v.startsd       := '0';
      v.startsdold    := '0';
      v.cfg.dllrst    := '0';
      v.cfg.cke       := '0';
    end if;

    ri <= v; 
    ribdrive <= vbdrive; 
    rwdata <= readdata;

  end process;

  sdo.sdcke     <= (others => r.cfg.cke);
  ahbso.hconfig <= hconfig;
  ahbso.hirq    <= (others => '0');
  ahbso.hindex  <= hindex;

  ahbregs : process(clk_ahb) begin 
    if rising_edge(clk_ahb) then
      ra <= rai; 
    end if;
  end process;

  ddrregs : process(clk_ddr, rst) begin 
    if rising_edge(clk_ddr) then
      r <= ri; rbdrive <= ribdrive;
    end if;
    if (rst = '0') then
      r.sdcsn  <= (others => '1'); r.bdrive <= '1'; r.nbdrive <= '0';
      if oepol = 0 then rbdrive <= (others => '1');
      else rbdrive <= (others => '0'); end if;
      r.cfg.cke <= '0';
    end if;
  end process;

  ddr_read_regs : process(clkread) begin 
    if rising_edge(clkread) then
      rwrite <= ri.hready; waddr2 <= r.waddr;
    end if;
  end process;

  sdo.address  <= '0' & ri.address;
  sdo.ba       <=  ri.ba;
  sdo.bdrive   <= r.nbdrive when oepol = 1 else r.bdrive;
  sdo.qdrive   <= not (ri.qdrive or r.nbdrive); 
  sdo.vbdrive  <= rbdrive; 
  sdo.sdcsn    <= ri.sdcsn;
  sdo.sdwen    <= ri.sdwen;
  sdo.dqm      <= "111111111111" & r.dqm;
  sdo.rasn     <= ri.rasn;
  sdo.casn     <= ri.casn;
  sdo.data     <= zero32 & zero32 & zero32 & wdata;

  read_buff : syncram_2p 
  generic map (tech => memtech, abits => 6, dbits => 32, sepclk => 1, wrfst => 0)
  port map ( rclk => clk_ahb, renable => vcc, raddress => rai.raddr,
    dataout => rdata, wclk => clk_ddr, write => ri.hready,
--    dataout => rdata, wclk => clkread, write => rwrite,
    waddress => r.waddr, datain => rwdata);
--    waddress => waddr2, datain => rwdata);

  write_buff : syncram_2p 
  generic map (tech => memtech, abits => 6, dbits => 32, sepclk => 1, wrfst => 0)
  port map ( rclk => clk_ddr, renable => vcc, raddress => r.waddr,
    dataout => wdata, wclk => clk_ahb, write => ra.write,
    waddress => ra.haddr(7 downto 2), datain => ahbsi.hwdata);

-- pragma translate_off
  bootmsg : report_version 
  generic map (
    msg1 => "ddrsp" & tost(hindex) & ": 16-bit DDR266 controller rev " & 
	tost(REVISION) & ", " & tost(Mbyte) & " Mbyte, " & tost(MHz) &
	" MHz DDR clock");
-- pragma translate_on

end;