Subversion Repositories uart_block

--! Top wishbone Master to test the uart_wishbone_slave

library ieee;

USE ieee.std_logic_1164.ALL;

use ieee.std_logic_unsigned.all;

use ieee.std_logic_arith.all;

--! Use CPU Definitions package

use work.pkgDefinitions.all;

entity SERIALMASTER is

        port(

            -- WISHBONE Signals

            ACK_I:  in  std_logic;

            ADR_O:  out std_logic_vector( 1 downto 0 );

            CLK_I:  in  std_logic;

            CYC_O:  out std_logic;

            DAT_I:  in  std_logic_vector( 31 downto 0 );

            DAT_O:  out std_logic_vector( 31 downto 0 );

            RST_I:  in  std_logic;

            SEL_O:  out std_logic;

            STB_O:  out std_logic;

            WE_O:   out std_logic;

                                -- NON-WISHBONE Signals

                                byte_rec : out std_logic_vector(7 downto 0)

         );

end SERIALMASTER;

architecture Behavioral of SERIALMASTER is

signal masterSerialStates : testMaster;

signal byteIncome : std_logic_vector(7 downto 0);

begin

        process (CLK_I)

        variable contWait : integer range 0 to 50000000;

        variable cycles2Wait : integer range 0 to 50000000;

        variable nextState: testMaster;

        begin

                if rising_edge(CLK_I) then

                        if RST_I = '1' then

                                masterSerialStates <= idle;

                                nextState := idle;

                                contWait := 0;

                                cycles2Wait := 25000000;

                                byteIncome <= conv_std_logic_vector(64, (nBitsLarge));  --Send the '@';

                        else

                                case masterSerialStates is

                                        when idle =>

                                                masterSerialStates <= config_clock;

                                                nextState := idle;

                                        when config_clock =>

                                                nextState := config_baud;

                                                ADR_O <= "00";

                                                WE_O <= '1';

                                                STB_O <= '1';

                                                DAT_O <= conv_std_logic_vector(50000000, (nBitsLarge));         -- 50Mhz

                                                if ACK_I = '1' then

                                                        -- Byte received wait some cycles to continue                                           

                                                        masterSerialStates <= wait_cycles;

                                                        byte_rec        <= "00000001";

                                                end if;

                                        when config_baud =>

                                                nextState := send_byte;

                                                ADR_O <= "01";

                                                WE_O <= '1';

                                                STB_O <= '1';

                                                DAT_O <= conv_std_logic_vector(115200, (nBitsLarge));   --115200 bps

                                                if ACK_I = '1' then

                                                        -- Byte received wait some cycles to continue

                                                        masterSerialStates <= wait_cycles;

                                                        byte_rec        <= "00000010";

                                                end if;

                                        when send_byte =>

                                                nextState := receive_byte;

                                                ADR_O <= "10";

                                                WE_O <= '1';

                                                STB_O <= '1';

                                                --DAT_O <= conv_std_logic_vector(64, (nBitsLarge));     --Send the '@'

                                                DAT_O <= conv_std_logic_vector(0, (nBitsLarge-8)) & byteIncome;  --Send the '@'

                                                if ACK_I = '1' then

                                                        -- Byte received wait some cycles to continue

                                                        masterSerialStates <= wait_cycles;

                                                        cycles2Wait     := 7000000;

                                                end if;

                                        when receive_byte =>

                                                nextState := send_byte;

                                                ADR_O <= "11";

                                                WE_O <= '0';

                                                STB_O <= '1';

                                                if ACK_I = '1' then

                                                        -- Byte received wait some cycles to continue

                                                        masterSerialStates <= wait_cycles;

                                                        byte_rec        <= DAT_I(7 downto 0);

                                                        byteIncome <= DAT_I(7 downto 0);

                                                        cycles2Wait     := 7000000;

                                                end if;

                                        when wait_cycles =>

                                                -- wait some cycles (90)

                                                if contWait < cycles2Wait then

                                                        contWait := contWait + 1;

                                                        STB_O <= '0';

                                                else

                                                        contWait := 0;

                                                        masterSerialStates <= nextState;

                                                end if;

                                end case;

                        end if;

                end if;

        end process;

end Behavioral;