git.zerfleddert.de Git - raggedstone/blob - dhwk/source/SER_PAR_CON.vhd

   1 -- $Id: SER_PAR_CON.vhd,v 1.1 2007-03-10 11:24:03 sithglan Exp $
   2
   3 library ieee;
   4 use ieee.std_logic_1164.all;
   5 use ieee.std_logic_unsigned.all;
   6
   7 entity SER_PAR_CON is
   8         port
   9         (
  10         PCI_CLOCK                       :in     std_logic;
  11         RESET                           :in     std_logic;
  12         SPC_ENABLE                      :in     std_logic; -- Driver Enable Sender/Receiver
  13         SYNC_R_FIFO_FFn                 :in     std_logic; -- FIFO Full Flag (low active)
  14         SERIAL_IN                       :in     std_logic; -- Serial Input
  15         R_FIFO_WRITEn                   :out    std_logic; -- FIFO Write (low active)
  16         SPC_RDY_OUT                     :out    std_logic; -- Ready to Receive Data
  17         PAR_OUT                         :out    std_logic_vector(7 downto 0)
  18         );
  19 end entity SER_PAR_CON ;
  20
  21
  22 architecture SER_PAR_CON_DESIGN of SER_PAR_CON is
  23
  24 -- constant STATE_RECV            :std_logic_vector(3 downto 0) := "0001";
  25 constant STATE_RECV_START_BIT  :std_logic_vector(3 downto 0) := "0010";
  26 constant STATE_RECV_BIT_0      :std_logic_vector(3 downto 0) := "0011";
  27 constant STATE_RECV_BIT_1      :std_logic_vector(3 downto 0) := "0100";
  28 constant STATE_RECV_BIT_2      :std_logic_vector(3 downto 0) := "0101";
  29 constant STATE_RECV_BIT_3      :std_logic_vector(3 downto 0) := "0110";
  30 constant STATE_RECV_BIT_4      :std_logic_vector(3 downto 0) := "0111";
  31 constant STATE_RECV_BIT_5      :std_logic_vector(3 downto 0) := "1000";
  32 constant STATE_RECV_BIT_6      :std_logic_vector(3 downto 0) := "1001";
  33 constant STATE_RECV_BIT_7      :std_logic_vector(3 downto 0) := "1010";
  34 constant STATE_RECV_FIFOFULL   :std_logic_vector(3 downto 0) := "1011";
  35
  36 signal COUNT     :std_logic_vector (3 downto 0);
  37 signal STATE     :std_logic_vector (3 downto 0);
  38 signal STARTBIT  :std_logic_vector (3 downto 0);
  39
  40
  41 attribute syn_state_machine:boolean;
  42 attribute syn_state_machine of STATE: signal is false;
  43 attribute syn_state_machine of COUNT: signal is false;
  44
  45 begin
  46
  47 process(PCI_CLOCK)
  48 begin
  49         if (PCI_CLOCK'event and PCI_CLOCK = '1') then
  50                                                 if ("0000" < COUNT) then
  51                                                 COUNT <= COUNT - 1;
  52                                         end if;
  53
  54 -- war nicht das Problem des Datenverlusts
  55 --        if (R_FIFO_WRITEn = '0' and COUNT = "0000") then
  56 --            R_FIFO_WRITEn <= '1';
  57 ---      end if;
  58
  59                 if (RESET = '1') then
  60                         STATE <= STATE_RECV_START_BIT;
  61                         COUNT <= "0000";
  62                         R_FIFO_WRITEn <= '1';
  63
  64                 elsif (SPC_ENABLE = '1') then
  65
  66                                                                                          if (STATE = STATE_RECV_START_BIT) then
  67                               R_FIFO_WRITEn <= '1';
  68                                                                                                 if (STARTBIT = "0011") then
  69                                                                                                                                 COUNT <= "0011";
  70                                     STATE <= STATE_RECV_BIT_0;
  71                               end if;
  72
  73                        elsif (STATE = STATE_RECV_FIFOFULL) then
  74                               if (SYNC_R_FIFO_FFn = '1') then
  75                                       R_FIFO_WRITEn <= '0';
  76                                       STATE <= STATE_RECV_START_BIT;
  77                               end if;
  78
  79                        elsif (COUNT = "0000") then
  80                         COUNT <= "0011";
  81                         case STATE is
  82
  83                                 when STATE_RECV_BIT_0 =>
  84                                         PAR_OUT(0) <= STARTBIT(0);
  85                                         STATE <= STATE_RECV_BIT_1;
  86
  87                                 when STATE_RECV_BIT_1 =>
  88                                         PAR_OUT(1) <= STARTBIT(0);
  89                                         STATE <= STATE_RECV_BIT_2;
  90
  91                                 when STATE_RECV_BIT_2 =>
  92                                         PAR_OUT(2) <= STARTBIT(0);
  93                                         STATE <= STATE_RECV_BIT_3;
  94
  95                                 when STATE_RECV_BIT_3 =>
  96                                         PAR_OUT(3) <= STARTBIT(0);
  97                                         STATE <= STATE_RECV_BIT_4;
  98
  99                                 when STATE_RECV_BIT_4 =>
 100                                         PAR_OUT(4) <= STARTBIT(0);
 101                                         STATE <= STATE_RECV_BIT_5;
 102
 103                                 when STATE_RECV_BIT_5 =>
 104                                         PAR_OUT(5) <= STARTBIT(0);
 105                                         STATE <= STATE_RECV_BIT_6;
 106
 107                                 when STATE_RECV_BIT_6 =>
 108                                         PAR_OUT(6) <= STARTBIT(0);
 109                                         STATE <= STATE_RECV_BIT_7;
 110
 111                                 when STATE_RECV_BIT_7 =>
 112                                         PAR_OUT(7) <= STARTBIT(0);
 113
 114                                         if (SYNC_R_FIFO_FFn = '1') then
 115                                              STATE <= STATE_RECV_START_BIT;
 116                                              R_FIFO_WRITEn <= '0';
 117                                         else
 118                                              STATE <= STATE_RECV_FIFOFULL;
 119                                         end if;
 120
 121                                                                                                                                 when others =>
 122                                                                                                                                                                 STATE <= STATE_RECV_START_BIT;
 123
 124                         end case;
 125                      end if; -- COUNT
 126                 end if; -- RESET ... / SPC_ENABLE ...
 127         end if; -- PCI_CLOCK ...
 128 end process;
 129
 130 process(PCI_CLOCK)
 131 begin
 132                 if (PCI_CLOCK'event and PCI_CLOCK = '1') then
 133       SPC_RDY_OUT <= SPC_ENABLE AND SYNC_R_FIFO_FFn;
 134                 end if;
 135 end process;
 136
 137
 138 process(PCI_CLOCK)
 139 begin
 140         if (PCI_CLOCK'event and PCI_CLOCK = '1') then
 141                                         if (RESET = '1') then
 142                                                 STARTBIT <= "0000";
 143                                         else
 144                                         STARTBIT(0) <= SERIAL_IN;
 145                                         STARTBIT(1) <= STARTBIT(0);
 146                                         STARTBIT(2) <= STARTBIT(1);
 147                                         STARTBIT(3) <= STARTBIT(2);
 148                                         end if;
 149                         end if;
 150 end process;
 151
 152
 153
 154 end architecture SER_PAR_CON_DESIGN;