davincihd.vhd.bak

DaVinci HD CPLD Firmware Resources 这是TI原装开发板DM6467原理图的 CPLD的VHDL代码

            sync_scl <= "0000";
        elsif ( CLKIN'event and CLKIN = '1' ) then
            sync_scl(0) <= PIN_I2C_SCL;
            sync_scl(1) <= sync_scl(0);
            sync_scl(2) <= sync_scl(1);
            if ( sync_scl(2) = sync_scl(1) ) then
                sync_scl(3) <= sync_scl(2);
            end if;
        end if;
    end process;

    -- Sync to falling edge of clock
    process ( Reset_SYSTEM, CLKIN, PIN_I2C_SDA_IN )
    begin
        if ( Reset_SYSTEM = '1' ) then
            sync_sda <= "0000";
        elsif ( CLKIN'event and CLKIN = '0' ) then
            sync_sda(0) <= PIN_I2C_SDA_IN;
            sync_sda(1) <= sync_sda(0);
            sync_sda(2) <= sync_sda(1);
            if ( sync_sda(2) = sync_sda(1) ) then
                sync_sda(3) <= sync_sda(2);
            end if;
        end if;
    end process;

    -- I2C signals are Sync to clock
    I2C_SCL      <= sync_scl(3);
    I2C_SDA_IN   <= sync_sda(3);

    process ( Reset_SYSTEM, STATE, I2C_SCL, START, STOP,
              RIGHT_ADDR, WRONG_ADDR, DATA_READ, DATA_WRITE )
    begin
        if ( Reset_SYSTEM = '1' ) then
            STATE <= s0;
        elsif ( I2C_SCL = '0' and I2C_SCL'event ) then
            case STATE is
                when s0 =>
                    if ( START = '1' ) then
                        STATE <= s1;
                    else
                        STATE <= s0;
                    end if;
                when s1 =>
                    if ( RIGHT_ADDR = '1' ) then
                        STATE <= s2;
                    elsif ( WRONG_ADDR = '1' ) then
                        STATE <= s0;
                    else
                        STATE <= s1;
                    end if;
                when s2 =>
                    if ( DATA_ACK = '1' or DATA_WRITE = '1' or STOP = '1' ) then
                        STATE <= s0;
                    else
                        STATE <= s2;
                    end if;
            end case;
        end if;
    end process;

    -----------------------------------------------------------------------------
    -- Start condition detection
    process ( STATE, I2C_SCL, I2C_SDA_IN )
    begin
        if ( I2C_SCL = '1' ) then
            if ( I2C_SDA_IN = '0' and I2C_SDA_IN'event ) then
                START <= '1';
            end if;
        else
            START <= '0';
        end if;
    end process;

    -----------------------------------------------------------------------------
    -- Stop condition detection
    process( STATE, I2C_SCL, I2C_SDA_IN )
    begin
        if ( I2C_SCL = '1' ) then
            if ( I2C_SDA_IN = '1' and I2C_SDA_IN'event ) then
                if ( STATE = s0 ) then
                    STOP <= '0';
                else
                    STOP <= '1';
                end if;
            end if;
        else
            STOP <= '0';
        end if;
    end process;

    ------------------------------------------------------------------------------
    -- ACK Back & Send DATA Out
    I2C_SDA_OUT <= '0' when ( Reset_SYSTEM = '0' )  -- Not in Reset
                        and ( ADDR_ACK = '1'        -- Ack to Address
                           or DATA_ACK = '1'        -- Ack to 8-bit Data Write
                           or DATA_OUT = '0' )      -- Output of Data Read
                       else 'Z';

    ------------------------------------------------------------------------------
    -- Shift in Address
    process ( STATE, I2C_SCL, I2C_SDA_IN, ADDR_IN_BUF )
    begin
        if ( STATE = s1 ) then
            if ( I2C_SCL = '1' and I2C_SCL'event ) then
                ADDR_IN_BUF(9 downto 0) <= ADDR_IN_BUF(8 downto 0) & I2C_SDA_IN;
            end if;
        else
            ADDR_IN_BUF <= "0000000010"; -- Built in Counter at index [0]
        end if;
    end process;

    ------------------------------------------------------------------------------
    -- Check Address
    process ( STATE, I2C_SCL, ADDR_IN_BUF )
    begin
        if ( STATE = s1 ) then
            if ( I2C_SCL = '0' and I2C_SCL'event and ADDR_IN_BUF(9) = '1' ) then
                -- 0x3A
                if ( ADDR_IN_BUF(7 downto 1) = "0111010" ) then
                    -- Right Address
                    RIGHT_ADDR <= '1';
                    ADDR_ACK   <= '1';

                    -- Store Reg address & Data direction
                    REG_ADDR      <= "00";
                    READ_OR_WRITE <= ADDR_IN_BUF(0);

                -- 0x3B
                elsif ( ADDR_IN_BUF(7 downto 1) = "0111011" ) then
                    RIGHT_ADDR <= '1';
                    ADDR_ACK   <= '1';

                    -- Store Reg address & Data direction
                    REG_ADDR      <= "01";
                    READ_OR_WRITE <= ADDR_IN_BUF(0);

                -- 0x3C
                elsif ( ADDR_IN_BUF(7 downto 1) = "0111100" ) then
                    RIGHT_ADDR <= '1';
                    ADDR_ACK   <= '1';

                    -- Store Reg address & Data direction
                    REG_ADDR      <= "10";
                    READ_OR_WRITE <= ADDR_IN_BUF(0);
                else
                    -- Wrong Address
                    WRONG_ADDR <= '1';
                    ADDR_ACK   <= '0';
                end if;
            end if;
        else
            ADDR_ACK   <= '0';
            RIGHT_ADDR <= '0';
            WRONG_ADDR <= '0';
        end if;
    end process;

    ------------------------------------------------------------------------------
    -- Shift in Data
    process ( STATE, I2C_SCL, I2C_SDA_IN, DATA_IN_BUF )
    begin
        if ( STATE = s2 ) then
            if ( I2C_SCL = '1' and I2C_SCL'event ) then
                DATA_IN_BUF(9 downto 0) <= DATA_IN_BUF(8 downto 0) & I2C_SDA_IN;
            end if;
        else
            DATA_IN_BUF <= "0000000010"; -- Built in Counter at index [0]
        end if;
    end process;

    ------------------------------------------------------------------------------
    -- Shift out Data
    process ( STATE, I2C_SCL, I2C_SDA_IN, RIGHT_ADDR, READ_OR_WRITE, REG_ADDR, DATA_OUT_BUF, Reg0, Reg1 )
    begin
        if ( STATE = s0 ) then
            DATA_OUT_BUF <= "11111111";
        elsif ( STATE = s1 ) then
            if ( RIGHT_ADDR = '1' and READ_OR_WRITE = '1' ) then
                if ( REG_ADDR = "00" ) then
                    DATA_OUT_BUF <= Reg0;
                elsif ( REG_ADDR = "01" ) then
                    DATA_OUT_BUF <= Reg1;
                elsif ( REG_ADDR = "10" ) then
                    DATA_OUT_BUF <= "00000110"; -- Reg2 = 6;
                else
                    DATA_OUT_BUF <= "00000000";
                end if;
            end if;
        elsif ( STATE = s2 ) then
            if ( I2C_SCL = '0' and I2C_SCL'event and READ_OR_WRITE = '1' ) then
                DATA_OUT_BUF <= DATA_OUT_BUF(6 downto 0) & '1';
            end if;
        end if;
    end process;

    DATA_OUT <= DATA_OUT_BUF(7);

    ------------------------------------------------------------------------------
    -- Send Ack & Data
    process ( STATE, I2C_SCL, DATA_IN_BUF )
    begin
        if ( STATE = s2 ) then
            if ( I2C_SCL = '0' and I2C_SCL'event ) then
                -- Write [to Own Register]
                if ( READ_OR_WRITE = '0' ) then
                    if ( DATA_IN_BUF(8) = '1' ) then
                        DATA_READ <= '1';
                        DATA_ACK <= '0';
                    elsif ( DATA_IN_BUF(9) = '1' ) then
                        DATA_READ <= '0';
                        DATA_ACK <= '1';
                    end if;

                -- Read [from Own Register]
                elsif ( READ_OR_WRITE = '1' ) then
                    DATA_ACK <= '0';
                    if ( DATA_IN_BUF(8) = '1' ) then
                        DATA_WRITE <= '1';
                    end if;

                end if;
           end if;
        else
            DATA_ACK <= '0';
            DATA_READ <= '0';
            DATA_WRITE <= '0';
        end if;
    end process;

    ------------------------------------------------------------------------------
    -- SAVE DATA
    process ( Reset_SYSTEM, STATE, I2C_SCL, STOP, DATA_IN_BUF, REG_ADDR, DATA_READ )
    begin
        if ( Reset_SYSTEM = '1' ) then
            Reg0 <= "00000011";
            --Reg0 <= "00000000";
            Reg1 <= "00000000";
        else
            if ( I2C_SCL = '0' and I2C_SCL'event and DATA_READ = '1' ) then
                if ( REG_ADDR = "00" ) then
                    Reg0 <= DATA_IN_BUF(7 downto 0);
                elsif ( REG_ADDR = "01" ) then
                    Reg1 <= DATA_IN_BUF(7 downto 0);
                end if;
            end if;
        end if;
    end process;

end behavior_davincihd;