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[/] [w11/] [tags/] [w11a_V0.7/] [rtl/] [vlib/] [rbus/] [rb_sel.vhd] - Rev 36
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-- $Id: rb_sel.vhd 641 2015-02-01 22:12:15Z mueller $ -- -- Copyright 2010-2014 by Walter F.J. Mueller <W.F.J.Mueller@gsi.de> -- -- This program is free software; you may redistribute and/or modify it under -- the terms of the GNU General Public License as published by the Free -- Software Foundation, either version 2, or at your option any later version. -- -- This program 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 General Public License -- for complete details. -- ------------------------------------------------------------------------------ -- Module Name: rb_sel - syn -- Description: rbus: address select logic -- -- Dependencies: - -- Test bench: - -- Target Devices: generic -- Tool versions: ise 12.1-14.7; viv 2014.4; ghdl 0.29-0.31 -- -- Revision History: -- Date Rev Version Comment -- 2014-08-15 583 4.0 rb_mreq addr now 16 bit -- 2010-12-26 349 1.0 Initial version (cloned from ibus/ib_sel) ------------------------------------------------------------------------------ library ieee; use ieee.std_logic_1164.all; use work.slvtypes.all; use work.rblib.all; -- ---------------------------------------------------------------------------- entity rb_sel is -- rbus address select logic generic ( RB_ADDR : slv16; -- rbus address base SAWIDTH : natural := 0); -- device subaddress space width port ( CLK : in slbit; -- clock RB_MREQ : in rb_mreq_type; -- ibus request SEL : out slbit -- select state bit ); end rb_sel; architecture syn of rb_sel is signal R_SEL : slbit := '0'; begin assert SAWIDTH<=15 -- at most 32k word devices report "assert(SAWIDTH<=15)" severity failure; proc_regs: process (CLK) variable isel : slbit := '0'; begin if rising_edge(CLK) then isel := '0'; if RB_MREQ.aval='1' and RB_MREQ.addr(15 downto SAWIDTH)=RB_ADDR(15 downto SAWIDTH) then isel := '1'; end if; R_SEL <= isel; end if; end process proc_regs; SEL <= R_SEL; end syn;
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