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[/] [mod_sim_exp/] [trunk/] [rtl/] [vhdl/] [core/] [fifo_primitive.vhd] - Rev 92
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---------------------------------------------------------------------- ---- fifo_primitive ---- ---- ---- ---- This file is part of the ---- ---- Modular Simultaneous Exponentiation Core project ---- ---- http://www.opencores.org/cores/mod_sim_exp/ ---- ---- ---- ---- Description ---- ---- 512 x 32 bit fifo ---- ---- ---- ---- Dependencies: ---- ---- - FIFO18E1 (xilinx primitive) ---- ---- ---- ---- Authors: ---- ---- - Geoffrey Ottoy, DraMCo research group ---- ---- - Jonas De Craene, JonasDC@opencores.org ---- ---- ---- ---------------------------------------------------------------------- ---- ---- ---- Copyright (C) 2011 DraMCo research group and OPENCORES.ORG ---- ---- ---- ---- This source file may be used and distributed without ---- ---- restriction provided that this copyright statement is not ---- ---- removed from the file and that any derivative work contains ---- ---- the original copyright notice and the associated disclaimer. ---- ---- ---- ---- This source file is free software; you can redistribute it ---- ---- and/or modify it under the terms of the GNU Lesser General ---- ---- Public License as published by the Free Software Foundation; ---- ---- either version 2.1 of the License, or (at your option) any ---- ---- later version. ---- ---- ---- ---- This source is distributed in the hope that it will be ---- ---- useful, but WITHOUT ANY WARRANTY; without even the implied ---- ---- warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR ---- ---- PURPOSE. See the GNU Lesser General Public License for more ---- ---- details. ---- ---- ---- ---- You should have received a copy of the GNU Lesser General ---- ---- Public License along with this source; if not, download it ---- ---- from http://www.opencores.org/lgpl.shtml ---- ---- ---- ---------------------------------------------------------------------- library ieee; use ieee.std_logic_1164.all; use ieee.std_logic_arith.all; use ieee.std_logic_unsigned.all; -- Xilinx primitives used in this code. library UNISIM; use UNISIM.VComponents.all; entity fifo_primitive is port ( clk : in std_logic; din : in std_logic_vector (31 downto 0); dout : out std_logic_vector (31 downto 0); empty : out std_logic; full : out std_logic; push : in std_logic; pop : in std_logic; reset : in std_logic; nopop : out std_logic; nopush : out std_logic ); end fifo_primitive; architecture Behavioral of fifo_primitive is signal rdcount : std_logic_vector(11 downto 0); -- debugging signal wrcount : std_logic_vector(11 downto 0); -- debugging signal reset_i, pop_i, push_i, empty_i, full_i, wrerr_i, rderr_i : std_logic; begin empty <= empty_i; full <= full_i; -- these logical equations need to be extended where necessary nopop <= rderr_i or (pop and reset_i); nopush <= wrerr_i or (push and reset_i); pop_i <= pop and (not reset_i); push_i <= push and (not reset_i); -- makes the reset at least three clk_cycles long RESET_PROC: process (reset, clk) variable clk_counter : integer range 0 to 3 := 3; begin if reset = '1' then reset_i <= '1'; clk_counter := 3; elsif rising_edge(clk) then if clk_counter = 0 then clk_counter := 0; reset_i <= '0'; else clk_counter := clk_counter - 1; reset_i <= '1'; end if; end if; end process; FIFO18E1_inst : FIFO18E1 generic map ( ALMOST_EMPTY_OFFSET => X"00080", -- Sets the almost empty threshold ALMOST_FULL_OFFSET => X"00080", -- Sets almost full threshold DATA_WIDTH => 36, -- Sets data width to 4, 9, 18, or 36 DO_REG => 1, -- Enable output register (0 or 1) Must be 1 if EN_SYN = "FALSE" EN_SYN => TRUE, -- Specifies FIFO as dual-clock ("FALSE") or Synchronous ("TRUE") FIFO_MODE => "FIFO18_36", -- Sets mode to FIFO18 or FIFO18_36 FIRST_WORD_FALL_THROUGH => FALSE, -- Sets the FIFO FWFT to "TRUE" or "FALSE" INIT => X"000000000", -- Initial values on output port SRVAL => X"000000000" -- Set/Reset value for output port ) port map ( -- ALMOSTEMPTY => ALMOSTEMPTY, -- 1-bit almost empty output flag -- ALMOSTFULL => ALMOSTFULL, -- 1-bit almost full output flag DO => dout, -- 32-bit data output -- DOP => DOP, -- 4-bit parity data output EMPTY => empty_i, -- 1-bit empty output flag FULL => full_i, -- 1-bit full output flag -- WRCOUNT, RDCOUNT: 12-bit (each) FIFO pointers RDCOUNT => RDCOUNT, -- 12-bit read count output WRCOUNT => WRCOUNT, -- 12-bit write count output -- WRERR, RDERR: 1-bit (each) FIFO full or empty error RDERR => rderr_i, -- 1-bit read error output WRERR => wrerr_i, -- 1-bit write error DI => din, -- 32-bit data input DIP => "0000", -- 4-bit parity input RDEN => pop_i, -- 1-bit read enable input REGCE => '1', -- 1-bit clock enable input RST => reset_i, -- 1-bit reset input RSTREG => reset_i, -- 1-bit output register set/reset -- WRCLK, RDCLK: 1-bit (each) Clocks RDCLK => clk, -- 1-bit read clock input WRCLK => clk, -- 1-bit write clock input WREN => push_i -- 1-bit write enable input ); end Behavioral;
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