datalink_sender

Library IEEE;
use IEEE.std_logic_1164.all;
use IEEE.std_logic_arith.all;
use IEEE.std_logic_unsigned.all;

entity datalink_sender is
    port
    (
    din     : in  std_logic_vector (7 downto 0);
    clk50Mhz : in std_logic;
    clkPacket: in std_logic;
    clkShift    : in std_logic;
    output  : out std_logic;
    triggerTouC : out std_logic
    );
end datalink_sender;

architecture arch of datalink_sender is

signal manData : std_logic_vector (15 downto 0);

TYPE SenderState IS (packetTrigger, packetStartDelay, readByte, readByteDelay, idle);
signal sstate : SenderState;

signal triggerSignal : std_logic;
signal bitOut : std_logic;

begin

triggerTouC <= triggerSignal;
output <= bitOut;

process(clk50Mhz, clkShift)

constant bytePerPacket : integer := 320;
constant packetDelay : integer := 144;
constant byteDelay : integer := 70;

variable byteCount : integer;
variable delayCount : integer;
variable bitCount : integer;
begin

if(falling_edge(clk50Mhz))then

    CASE sstate IS
        WHEN idle =>
            --count for 1KHz
            if(falling_edge(clkPacket))then
                sstate <= packetTrigger;
                delayCount := 0;
            end if;

        WHEN packetTrigger =>
            byteCount := 0;
            triggerSignal <= '1';
            sstate <= packetStartDelay;

        WHEN packetStartDelay =>
            delayCount := delayCount+1;
            if(delayCount=packetDelay-byteDelay)then
                --put in SOF
                manData <= "0110101010101001";
            elsif(delayCount=packetDelay)then
                triggerSignal <= '0';
                sstate <= readByte;
            end if;

        WHEN readByte =>

            manData <= din(7)&NOT(din(7))&din(6)&NOT(din(6))&din(5)&NOT(din(5))&din(4)&NOT(din(4))&din(3)&NOT(din(3))&din(2)&NOT(din(2))&din(1)&NOT(din(1))&din(0)&NOT(din(0));
            delayCount := 0;
            byteCount := byteCount + 1;
            sstate <= readByteDelay;

        WHEN readByteDelay =>
            if(byteCount=bytePerPacket)then
                sstate <= idle;
            else
                delayCount := delayCount+1;
                if(delayCount=packetDelay)then
                    sstate <= readByte;
                end if;
            end if;

    END CASE;

end if;

end process;
end arch;