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[/] [w11/] [tags/] [w11a_V0.5/] [rtl/] [w11a/] [pdp11_mmu.vhd] - Rev 37
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-- $Id: pdp11_mmu.vhd 314 2010-07-09 17:38:41Z mueller $ -- -- Copyright 2006-2010 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: pdp11_mmu - syn -- Description: pdp11: mmu - memory management unit -- -- Dependencies: pdp11_mmu_sadr -- pdp11_mmu_ssr12 -- ibus/ib_sres_or_3 -- -- Test bench: tb/tb_pdp11_core (implicit) -- Target Devices: generic -- Tool versions: xst 8.1, 8.2, 9.1, 9.2; ghdl 0.18-0.25 -- Revision History: -- Date Rev Version Comment -- 2010-06-20 307 1.3.7 rename cpacc to cacc in mmu_cntl_type -- 2009-05-30 220 1.3.6 final removal of snoopers (were already commented) -- 2009-05-09 213 1.3.5 BUGFIX: tie inst_compl permanentely '0' -- BUGFIX: set ssr0 trap_mmu even when traps disabled -- 2008-08-22 161 1.3.4 rename pdp11_ibres_ -> ib_sres_, ubf_ -> ibf_ -- 2008-04-27 139 1.3.3 allow ssr1/2 tracing even with mmu_ena=0 -- 2008-04-25 138 1.3.2 add BRESET port, clear ssr0/3 with BRESET -- 2008-03-02 121 1.3.1 remove snoopers -- 2008-02-24 119 1.3 return always mapped address in PADDRH; remove -- cpacc handling; PADDR generation now on _vmbox -- 2008-01-05 110 1.2.1 rename _mmu_regs -> _mmu_sadr -- rename IB_MREQ(ena->req) SRES(sel->ack, hold->busy) -- 2008-01-01 109 1.2 use pdp11_mmu_regs (rather than _regset) -- 2007-12-31 108 1.1.1 remove SADR memory address mux (-> _mmu_regfile) -- 2007-12-30 107 1.1 use IB_MREQ/IB_SRES interface now -- 2007-06-14 56 1.0.1 Use slvtypes.all -- 2007-05-12 26 1.0 Initial version ------------------------------------------------------------------------------ library ieee; use ieee.std_logic_1164.all; use ieee.std_logic_arith.all; use work.slvtypes.all; use work.iblib.all; use work.pdp11.all; -- ---------------------------------------------------------------------------- entity pdp11_mmu is -- mmu - memory management unit port ( CLK : in slbit; -- clock CRESET : in slbit; -- console reset BRESET : in slbit; -- ibus reset CNTL : in mmu_cntl_type; -- control port VADDR : in slv16; -- virtual address MONI : in mmu_moni_type; -- monitor port STAT : out mmu_stat_type; -- status port PADDRH : out slv16; -- physical address (upper 16 bit) IB_MREQ: in ib_mreq_type; -- ibus request IB_SRES: out ib_sres_type -- ibus response ); end pdp11_mmu; architecture syn of pdp11_mmu is constant ibaddr_ssr0 : slv16 := conv_std_logic_vector(8#177572#,16); constant ibaddr_ssr3 : slv16 := conv_std_logic_vector(8#172516#,16); constant ssr0_ibf_abo_nonres : integer := 15; constant ssr0_ibf_abo_length : integer := 14; constant ssr0_ibf_abo_rdonly : integer := 13; constant ssr0_ibf_trap_mmu : integer := 12; constant ssr0_ibf_ena_trap : integer := 9; constant ssr0_ibf_inst_compl : integer := 7; subtype ssr0_ibf_seg_mode is integer range 6 downto 5; constant ssr0_ibf_dspace : integer := 4; subtype ssr0_ibf_seg_num is integer range 3 downto 1; constant ssr0_ibf_ena_mmu : integer := 0; constant ssr3_ibf_ena_ubmap : integer := 5; constant ssr3_ibf_ena_22bit : integer := 4; constant ssr3_ibf_dspace_km : integer := 2; constant ssr3_ibf_dspace_sm : integer := 1; constant ssr3_ibf_dspace_um : integer := 0; signal IBSEL_SSR0 : slbit := '0'; -- ibus select SSR0 signal IBSEL_SSR3 : slbit := '0'; -- ibus select SSR3 signal R_SSR0 : mmu_ssr0_type := mmu_ssr0_init; signal N_SSR0 : mmu_ssr0_type := mmu_ssr0_init; signal R_SSR3 : mmu_ssr3_type := mmu_ssr3_init; signal ASN : slv4 := "0000"; -- augmented segment number (1+3 bit) signal AIB_WE : slbit := '0'; -- update AIB signal AIB_SETA : slbit := '0'; -- set A bit in access information bits signal AIB_SETW : slbit := '0'; -- set W bit in access information bits signal TRACE : slbit := '0'; -- enable tracing in ssr1/2 signal DSPACE : slbit := '0'; -- use dspace signal IB_SRES_SADR : ib_sres_type := ib_sres_init; signal IB_SRES_SSR12 : ib_sres_type := ib_sres_init; signal IB_SRES_SSR03 : ib_sres_type := ib_sres_init; signal SARSDR : sarsdr_type := sarsdr_init; begin SADR : pdp11_mmu_sadr port map ( CLK => CLK, MODE => CNTL.mode, ASN => ASN, AIB_WE => AIB_WE, AIB_SETA => AIB_SETA, AIB_SETW => AIB_SETW, SARSDR => SARSDR, IB_MREQ => IB_MREQ, IB_SRES => IB_SRES_SADR); SSR12 : pdp11_mmu_ssr12 port map ( CLK => CLK, CRESET => CRESET, TRACE => TRACE, MONI => MONI, IB_MREQ => IB_MREQ, IB_SRES => IB_SRES_SSR12); IB_SRES_OR : ib_sres_or_3 port map ( IB_SRES_1 => IB_SRES_SADR, IB_SRES_2 => IB_SRES_SSR12, IB_SRES_3 => IB_SRES_SSR03, IB_SRES_OR => IB_SRES); proc_ibsel: process (IB_MREQ) variable issr0 : slbit := '0'; variable issr3 : slbit := '0'; begin issr0 := '0'; issr3 := '0'; if IB_MREQ.req = '1' then if IB_MREQ.addr = ibaddr_ssr0(12 downto 1) then issr0 := '1'; end if; if IB_MREQ.addr = ibaddr_ssr3(12 downto 1) then issr3 := '1'; end if; end if; IBSEL_SSR0 <= issr0; IBSEL_SSR3 <= issr3; IB_SRES_SSR03.ack <= issr0 or issr3; IB_SRES_SSR03.busy <= '0'; end process proc_ibsel; proc_ibdout : process (IBSEL_SSR0, IBSEL_SSR3, R_SSR0, R_SSR3) variable ssr0out : slv16 := (others=>'0'); variable ssr3out : slv16 := (others=>'0'); begin ssr0out := (others=>'0'); if IBSEL_SSR0 = '1' then ssr0out(ssr0_ibf_abo_nonres) := R_SSR0.abo_nonres; ssr0out(ssr0_ibf_abo_length) := R_SSR0.abo_length; ssr0out(ssr0_ibf_abo_rdonly) := R_SSR0.abo_rdonly; ssr0out(ssr0_ibf_trap_mmu) := R_SSR0.trap_mmu; ssr0out(ssr0_ibf_ena_trap) := R_SSR0.ena_trap; ssr0out(ssr0_ibf_inst_compl) := R_SSR0.inst_compl; ssr0out(ssr0_ibf_seg_mode) := R_SSR0.seg_mode; ssr0out(ssr0_ibf_dspace) := R_SSR0.dspace; ssr0out(ssr0_ibf_seg_num) := R_SSR0.seg_num; ssr0out(ssr0_ibf_ena_mmu) := R_SSR0.ena_mmu; end if; ssr3out := (others=>'0'); if IBSEL_SSR3 = '1' then ssr3out(ssr3_ibf_ena_ubmap) := R_SSR3.ena_ubmap; ssr3out(ssr3_ibf_ena_22bit) := R_SSR3.ena_22bit; ssr3out(ssr3_ibf_dspace_km) := R_SSR3.dspace_km; ssr3out(ssr3_ibf_dspace_sm) := R_SSR3.dspace_sm; ssr3out(ssr3_ibf_dspace_um) := R_SSR3.dspace_um; end if; IB_SRES_SSR03.dout <= ssr0out or ssr3out; end process proc_ibdout; proc_ssr0 : process (CLK) begin if CLK'event and CLK='1' then if BRESET = '1' then R_SSR0 <= mmu_ssr0_init; else R_SSR0 <= N_SSR0; end if; end if; end process proc_ssr0; proc_ssr3 : process (CLK) begin if CLK'event and CLK='1' then if BRESET = '1' then R_SSR3 <= mmu_ssr3_init; elsif IB_MREQ.we='1' and IBSEL_SSR3='1' then if IB_MREQ.be0 = '1' then R_SSR3.ena_ubmap <= IB_MREQ.din(ssr3_ibf_ena_ubmap); R_SSR3.ena_22bit <= IB_MREQ.din(ssr3_ibf_ena_22bit); R_SSR3.dspace_km <= IB_MREQ.din(ssr3_ibf_dspace_km); R_SSR3.dspace_sm <= IB_MREQ.din(ssr3_ibf_dspace_sm); R_SSR3.dspace_um <= IB_MREQ.din(ssr3_ibf_dspace_um); end if; end if; end if; end process proc_ssr3; proc_paddr : process (R_SSR0, R_SSR3, CNTL, SARSDR, VADDR) variable ipaddrh : slv16 := (others=>'0'); variable dspace_ok : slbit := '0'; variable dspace_en : slbit := '0'; variable asf : slv3 := (others=>'0'); -- va: active segment field variable bn : slv7 := (others=>'0'); -- va: block number variable iasn : slv4 := (others=>'0');-- augmented segment number begin asf := VADDR(15 downto 13); bn := VADDR(12 downto 6); dspace_en := '0'; case CNTL.mode is when "00" => dspace_en := R_SSR3.dspace_km; when "01" => dspace_en := R_SSR3.dspace_sm; when "11" => dspace_en := R_SSR3.dspace_um; when others => null; end case; dspace_ok := CNTL.dspace and dspace_en; iasn(3) := dspace_ok; iasn(2 downto 0) := asf; ipaddrh := unsigned("000000000"&bn) + unsigned(SARSDR.saf); DSPACE <= dspace_ok; ASN <= iasn; PADDRH <= ipaddrh; end process proc_paddr; proc_nssr0 : process (R_SSR0, R_SSR3, IB_MREQ, IBSEL_SSR0, DSPACE, CNTL, MONI, SARSDR, VADDR) variable nssr0 : mmu_ssr0_type := mmu_ssr0_init; variable asf : slv3 := (others=>'0'); variable bn : slv7 := (others=>'0'); variable abo_nonres : slbit := '0'; variable abo_length : slbit := '0'; variable abo_rdonly : slbit := '0'; variable ssr_freeze : slbit := '0'; variable doabort : slbit := '0'; variable dotrap : slbit := '0'; variable dotrace : slbit := '0'; begin nssr0 := R_SSR0; AIB_WE <= '0'; AIB_SETA <= '0'; AIB_SETW <= '0'; ssr_freeze := R_SSR0.abo_nonres or R_SSR0.abo_length or R_SSR0.abo_rdonly; dotrace := not(CNTL.cacc or ssr_freeze); asf := VADDR(15 downto 13); bn := VADDR(12 downto 6); abo_nonres := '0'; abo_length := '0'; abo_rdonly := '0'; doabort := '0'; dotrap := '0'; if SARSDR.ed = '0' then -- ed=0: upward expansion if unsigned(bn) > unsigned(SARSDR.slf) then abo_length := '1'; end if; else -- ed=0: downward expansion if unsigned(bn) < unsigned(SARSDR.slf) then abo_length := '1'; end if; end if; case SARSDR.acf is -- evaluate accecc control field when "000" => -- segment non-resident abo_nonres := '1'; when "001" => -- read-only; trap on read if CNTL.wacc='1' or CNTL.macc='1' then abo_rdonly := '1'; end if; dotrap := '1'; when "010" => -- read-only if CNTL.wacc='1' or CNTL.macc='1' then abo_rdonly := '1'; end if; when "100" => -- read/write; trap on read&write dotrap := '1'; when "101" => -- read/write; trap on write dotrap := CNTL.wacc or CNTL.macc; when "110" => null; -- read/write; when others => -- unused codes: abort access abo_nonres := '1'; end case; if IB_MREQ.we='1' and IBSEL_SSR0='1' then if IB_MREQ.be1 = '1' then nssr0.abo_nonres := IB_MREQ.din(ssr0_ibf_abo_nonres); nssr0.abo_length := IB_MREQ.din(ssr0_ibf_abo_length); nssr0.abo_rdonly := IB_MREQ.din(ssr0_ibf_abo_rdonly); nssr0.trap_mmu := IB_MREQ.din(ssr0_ibf_trap_mmu); nssr0.ena_trap := IB_MREQ.din(ssr0_ibf_ena_trap); end if; if IB_MREQ.be0 = '1' then nssr0.ena_mmu := IB_MREQ.din(ssr0_ibf_ena_mmu); end if; elsif nssr0.ena_mmu='1' and CNTL.cacc='0' then if dotrace = '1' then if MONI.istart = '1' then nssr0.inst_compl := '0'; elsif MONI.idone = '1' then nssr0.inst_compl := '0'; -- disable instr.compl logic end if; end if; if CNTL.req = '1' then AIB_WE <= '1'; if ssr_freeze = '0' then nssr0.abo_nonres := abo_nonres; nssr0.abo_length := abo_length; nssr0.abo_rdonly := abo_rdonly; end if; doabort := abo_nonres or abo_length or abo_rdonly; if doabort = '0' then AIB_SETA <= '1'; AIB_SETW <= CNTL.wacc or CNTL.macc; end if; if ssr_freeze = '0' then nssr0.dspace := DSPACE; nssr0.seg_num := asf; nssr0.seg_mode := CNTL.mode; end if; end if; end if; if CNTL.req='1' and R_SSR0.ena_mmu='1' and CNTL.cacc='0' and dotrap='1' then nssr0.trap_mmu := '1'; end if; nssr0.trace_prev := dotrace; if MONI.trace_prev = '0' then TRACE <= dotrace; else TRACE <= R_SSR0.trace_prev; end if; N_SSR0 <= nssr0; if R_SSR0.ena_mmu='1' and CNTL.cacc='0' then STAT.vaok <= not doabort; else STAT.vaok <= '1'; end if; if R_SSR0.ena_mmu='1' and CNTL.cacc='0' and doabort='0' and R_SSR0.ena_trap='1' and R_SSR0.trap_mmu='0' and dotrap='1' then STAT.trap <= '1'; else STAT.trap <= '0'; end if; STAT.ena_mmu <= R_SSR0.ena_mmu; STAT.ena_22bit <= R_SSR3.ena_22bit; STAT.ena_ubmap <= R_SSR3.ena_ubmap; end process proc_nssr0; end syn;
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