Subversion Repositories uart_block

--! @file

--! @brief Top level for interconnection between communication blocks: serial_transmitter, serial_receiver, baud_generator

library IEEE;

use IEEE.STD_LOGIC_1164.ALL;

--! Use CPU Definitions package

use work.pkgDefinitions.all;

entity uart_communication_blocks is

    Port ( rst : in  STD_LOGIC;                                                                                                                 --! Global reset

           clk : in  STD_LOGIC;                                                                                                                 --! Global clock

                          cycle_wait_baud : in std_logic_vector((nBitsLarge-1) downto 0);        --! Number of cycles to wait in order to generate desired baud

           byte_tx : in  STD_LOGIC_VECTOR ((nBits-1) downto 0);                          --! Byte to transmit

           byte_rx : out  STD_LOGIC_VECTOR ((nBits-1) downto 0);                         --! Byte to receive

           data_sent_tx : out  STD_LOGIC;                                                                                               --! Indicate that byte has been sent

           data_received_rx : out  STD_LOGIC;                                                                           --! Indicate that we got a byte

                          serial_out : out std_logic;                                                                                                   --! Uart serial out

                          serial_in : in std_logic;                                                                                                     --! Uart serial in

           start_tx : in  STD_LOGIC);                                                                                                   --! Initiate transmission

end uart_communication_blocks;

--! @brief Top level for interconnection between communication blocks: serial_transmitter, serial_receiver, baud_generator

--! @details Declare used components for instantiation

architecture Behavioral of uart_communication_blocks is

-- Declare components...

component baud_generator is

    Port ( rst : in STD_LOGIC;                                                                                                          --! Reset Input

                          clk : in  STD_LOGIC;                                                                                                          --! Clock input

           cycle_wait : in  STD_LOGIC_VECTOR ((nBitsLarge-1) downto 0);  --! Number of cycles to wait for baud generation

                          baud_oversample : out std_logic;                                                                              --! Oversample(8x) version of baud (Used on serial_receiver)

           baud : out  STD_LOGIC);                                                                                                      --! Baud generation output (Used on serial_transmitter)

end component;

component serial_transmitter is

     Port ( rst : in  STD_LOGIC;                                                                                                --! Reset input

           baudClk : in  STD_LOGIC;                                                                                     --! Baud rate clock input

           data_byte : in  STD_LOGIC_VECTOR ((nBits-1) downto 0);        --! Byte to be sent

                          data_sent : out STD_LOGIC;                                                                            --! Indicate that byte has been sent

           serial_out : out  STD_LOGIC);                                                                        --! Uart serial output

end component;

component serial_receiver is

    Port (

                          rst : in STD_LOGIC;                                                                                                   --! Reset input           

                          baudOverSampleClk : in  STD_LOGIC;                                                            --! Baud oversampled 8x (Best way to detect start bit)

           serial_in : in  STD_LOGIC;                                                                                   --! Uart serial input

           data_ready : out  STD_LOGIC;                                                                         --! Data received and ready to be read

           data_byte : out  STD_LOGIC_VECTOR ((nBits-1) downto 0));      --! Data byte received

end component;

signal baud_tick : std_logic;

signal baud_tick_oversample : std_logic;

begin

        --! Instantiate baud generator

        uBaudGen : baud_generator port map (

                rst => rst,

                clk => clk,

                cycle_wait => cycle_wait_baud,

                baud_oversample => baud_tick_oversample,

                baud => baud_tick

        );

        --! Instantiate serial_transmitter

        uTransmitter : serial_transmitter port map (

                rst => not start_tx,

                baudClk => baud_tick,

                data_byte => byte_tx,

                data_sent => data_sent_tx,

                serial_out => serial_out

        );

        --! Instantiate serial_receiver

        uReceiver : serial_receiver port map(

                rst => rst,

                baudOverSampleClk => baud_tick_oversample,

                serial_in => serial_in,

                data_ready => data_received_rx,

                data_byte => byte_rx

        );

end Behavioral;