cfg_rom.vhd

pci控制器的vhdl代码。。。。。。。。。

--*****************************************************************************
-- FILE    : CFG_ROM.vhd
-- DATE    : 1.9.1999
-- REVISION: 1.1
-- DESIGNER: KA
-- Descr   :
-- Entities:  CFG_ROM
-- Changes :
-- ******************************************************
-- *         Configuration Space ROM Entity             *
-- ******************************************************
library IEEE;
use IEEE.std_logic_1164.all;
use IEEE.STD_LOGIC_UNSIGNED.all;
library WORK;
use WORK.CFGSPACE_SET.all;
entity CFG_ROM is
  port(
      ADR  : in  std_logic_vector(3 downto 0);
      DATA : out std_logic_vector(31 downto 0)
  ); end CFG_ROM;
--
-- ******************************************************
-- *                     Architecture                   *
-- ******************************************************

architecture RTL of CFG_ROM is
   subtype ROM_WORD is std_logic_vector (31 downto 0);
   type ROM_TABLE is array (0 to 15) of ROM_WORD;
   constant Zero_32 :ROM_WORD := "00000000000000000000000000000000";
   constant RomWord13 :ROM_WORD := "000000000000000000000000"& CAP_PTR;
   constant RomWord15 :ROM_WORD := MAX_LAT & MIN_GNT & INT_PIN &INT_LINE;
   constant ROM: ROM_TABLE := ROM_TABLE'(
      ROM_WORD'(DEVICE_ID & VENDOR_ID),      -- Device ID + Vendor ID
      ROM_WORD'(Zero_32),                    -- Unused (Status & Command)
      ROM_WORD'(CLASS_ID & REV_ID),          -- Class ID & SubClass & 
Interface & Revision ID
      ROM_WORD'(Zero_32),                    -- BIST + Header Type + Latency 
Timer + Cache Line Size
      ROM_WORD'(BAR0_MAP),                   -- BAR 0
      ROM_WORD'(BAR1_MAP),                   -- BAR 1
      ROM_WORD'(BAR2_MAP),                   -- BAR 2
      ROM_WORD'(BAR3_MAP),                   -- BAR 3
      ROM_WORD'(BAR4_MAP),                   -- BAR 4
      ROM_WORD'(BAR5_MAP),                   -- BAR 5
      ROM_WORD'(Zero_32),                    -- CIS Pointer
      ROM_WORD'(SUBDEVICE_ID & SUBVENDOR_ID),-- Subsystem Device ID + 
Subsystem Vendor ID
      ROM_WORD'(EBAR_MAP),                   -- Expansion ROM BAR
      ROM_WORD'(RomWord13),                  -- Reserved + CAP_PTR
      ROM_WORD'(Zero_32),                    -- Reserved
      ROM_WORD'(MAX_LAT & MIN_GNT & INT_PIN &INT_LINE)); -- Max_LAT + 
Min_Gnt + Interrupt Pin + Interrupt Line
   signal ADRi :integer range 0 to 15;
begin
   ADRi <= CONV_INTEGER(ADR);
   DATA <= ROM(ADRi);          -- Read from the ROM
end RTL;