4 -- File: CONFIG_04H.VHD
 
   7 use IEEE.std_logic_1164.all;
 
  12                 PCI_CLOCK :in std_logic;
 
  13                 PCI_RSTn :in std_logic;
 
  16                 AD_REG :in std_logic_vector(31 downto 0);
 
  17                 CBE_REGn :in std_logic_vector( 3 downto 0);
 
  18                 CONF_WR_04H :in std_logic;
 
  19                 CONF_DATA_04H :out std_logic_vector(31 downto 0)
 
  21 end entity CONFIG_04H;
 
  23 architecture CONFIG_04H_DESIGN of CONFIG_04H is
 
  25         signal CONF_STATUS :std_logic_vector(31 downto 16);
 
  26         signal CONF_COMMAND :std_logic_vector(15 downto 0);
 
  30  --*******************************************************************
 
  31  --************* PCI Configuration Space Header "STATUS" *************
 
  32  --*******************************************************************
 
  34         CONF_STATUS(20 downto 16) <= "00000";-- Reserved
 
  35         CONF_STATUS(21 ) <= '0';-- MAS/TAR: "R_O" :'0'= 33MHz / '1'= 66MHz
 
  36         CONF_STATUS(22 ) <= '0';-- MAS/TAR: "R_O"
 
  37         CONF_STATUS(23 ) <= '0';-- ???/???: "R_O" : fast back-to-back
 
  38         CONF_STATUS(24 ) <= '0';-- Master :
 
  39         --CONF_STATUS(26 downto 25) <= "00";-- Mas/Tar: "R_O" : timing fast for "DEVSEL"
 
  40         CONF_STATUS(26 downto 25) <= "01";-- Mas/Tar: "R_O" : timing medium for "DEVSEL"
 
  41         --CONF_STATUS(26 downto 25) <= "10";-- Mas/Tar: "R_O" : timing slow for "DEVSEL"
 
  42         --CONF_STATUS(26 downto 25) <= "11";-- Mas/Tar: "R_O" : reserved
 
  43         CONF_STATUS(27 ) <= '0';-- Target : "R_W" : Taget-Abort
 
  44         CONF_STATUS(28 ) <= '0';-- Master : "R_W" : Taget-Abort
 
  45         CONF_STATUS(29 ) <= '0';-- Master : "R_W" : Master-Abort
 
  46         --CONF_STATUS(30 ) <= SERR;-- Mas/Tar: "R_W" : SERR
 
  47         --CONF_STATUS(31 ) <= PERR;-- Mas/Tar: "R_W" : PERR
 
  49         process (PCI_CLOCK,PCI_RSTn)
 
  51         if PCI_RSTn = '0' then
 
  52                 CONF_STATUS(30) <= '0';
 
  53                 CONF_STATUS(31) <= '0';
 
  55         elsif (PCI_CLOCK'event and PCI_CLOCK = '1') then
 
  56                 if CONF_WR_04H = '1' and CBE_REGn(3) = '0' then
 
  57                         CONF_STATUS(30) <= not (AD_REG(30) and CONF_STATUS(30));
 
  58                         CONF_STATUS(31) <= not (AD_REG(31) and CONF_STATUS(31));
 
  61                         CONF_STATUS(30) <= SERR or CONF_STATUS(30);
 
  62                         CONF_STATUS(31) <= PERR or CONF_STATUS(31);
 
  68  --*******************************************************************
 
  69  --*********** PCI Configuration Space Header "COMMAND" **************
 
  70  --*******************************************************************
 
  72 -- CONF_COMMAND( 0) <= '0';-- I/O Space accesses ???
 
  73 -- CONF_COMMAND( 1) <= '0';-- Mem Space accesses ???
 
  74 -- CONF_COMMAND( 2) <= '0';-- abillity to act as a master on the PCI bus
 
  75 -- CONF_COMMAND( 3) <= '0';-- Special Cycle ???
 
  76 -- CONF_COMMAND( 4) <= '0';-- Master ???
 
  77 -- CONF_COMMAND( 5) <= '0';-- VGA ???
 
  78 -- CONF_COMMAND( 6) <= '0';-- Party checking enable/disable
 
  79 CONF_COMMAND( 7) <= '0';-- address/data stepping ???
 
  80 -- CONF_COMMAND( 8) <= '0';-- enable/disable "PCI_SERRn"
 
  81 -- CONF_COMMAND( 9) <= '0';-- fast back-to-back
 
  82 -- CONF_COMMAND(10) <= '0';-- Reserved
 
  83 -- CONF_COMMAND(11) <= '0';-- Reserved
 
  84 -- CONF_COMMAND(12) <= '0';-- Reserved
 
  85 -- CONF_COMMAND(13) <= '0';-- Reserved
 
  86 -- CONF_COMMAND(14) <= '0';-- Reserved
 
  87 -- CONF_COMMAND(15) <= '0';-- Reserved
 
  89 process (PCI_CLOCK,PCI_RSTn)
 
  91         if PCI_RSTn = '0' then
 
  92                 CONF_COMMAND(15 downto 8) <= (others =>'0');
 
  93                 CONF_COMMAND( 6 downto 0) <= (others =>'0');
 
  95         elsif (PCI_CLOCK'event and PCI_CLOCK = '1') then
 
  97                 if CONF_WR_04H = '1'and CBE_REGn(1) = '0' then
 
  98                         CONF_COMMAND(15 downto 8) <= AD_REG(15 downto 8);
 
 100                         CONF_COMMAND(15 downto 8) <= CONF_COMMAND(15 downto 8);
 
 103                 if CONF_WR_04H = '1'and CBE_REGn(0) = '0' then
 
 104                         CONF_COMMAND( 6 downto 0) <= AD_REG( 6 downto 0);
 
 106                         CONF_COMMAND( 6 downto 0) <= CONF_COMMAND( 6 downto 0);
 
 111 CONF_DATA_04H <= CONF_STATUS & CONF_COMMAND;
 
 113 end architecture CONFIG_04H_DESIGN;