m3s018bo.vhd

来自「another 8051 core porocesssor vhdl sourc」· VHDL 代码 · 共 516 行 · 第 1/2 页

--*********************************************************************
setpodmen:process(NX2)
begin
    if NX2'event and NX2 = '1' then
       if DIV2CK = '0' then
          if ((STATD(4) and CYC(1) and MOVX(0)) ='1') then
             PODMEN <= '1';
          elsif ((STATD(4) and CYC(2)) or CLEAR or
                (MOVX(4) and STATD(5) and EXTDAT)) = '1' then
             PODMEN <= '0';
          end if;
        end if;
     end if;
end process setpodmen;
--*********************************************************************
setaddmen:process(NX2)
begin
    if NX2'event and NX2 = '1' then
       if CLEAR = '1' then
          P0DADD <= '0';
       elsif DIV2CK = '0' then
          if ((STATD(4) and CYC(1) and MOVX(0)) ='1') then
             P0DADD <= '1';
          end if;
       elsif DIV2CK ='1' then
          if (STATD(6) ='1') then
             P0DADD <= '0';
          end if;
       end if;
     end if;
end process setaddmen;
--*********************************************************************
latportin:process(NX2)
begin
  if NX2'event and NX2 = '1' then
       if DIV2CK ='0' then
          if STATD(4) ='1' then
             LAI_IN <= AI;
             LBI_IN <= BI;
             LCI_IN <= CI;
             LDI_IN <= DI;
           end if;
        end if;
   end if;
end process latportin;
--*********************************************************************
--External signals+directly related
--*********************************************************************
set_hlt:process(NX1,RST)
begin
    if RST = '1' then
        IDLE <= '0';
    elsif NX1'event and NX1 ='1' then
        IDLE <= PCON(0);
    end if;
end process set_hlt;
--*********************************************************************
setouts:process(NQEN,L_EXPMEM,IDLE,MOVX,PORT1_SFR,L_OC,L_OD)
begin
    NPSEN <= IDLE or NQEN or not L_EXPMEM;
    MOEI <= not (L_EXPMEM or NQEN);
    EXPMEM <= L_EXPMEM;
    OB <= PORT1_SFR;
    OC <= L_OC;
    OD <= L_OD;
end process setouts;
--*********************************************************************
aleout:process(QALE,IDLE)
begin
          ALE <= IDLE or QALE;
end process aleout;
--*********************************************************************
setqen:process(NX2,RST)
begin
    if RST = '1' then
       NQEN <= '1';
    elsif NX2'event and NX2 ='1' then
       if DIV2CK = '0' then
          if ((STATD(5) and not(CYC(1) and MOVX(0))) or 
             (STATD(2) and not CLEAR and not(CYC(2) and MOVX(0)))) = '1'
          then
                NQEN <= '0';
          end if;
       else
          if (STATD(1) or STATD(4)) = '1' then
                NQEN <= '1';
          end if;
       end if;
    end if;
end process setqen;
--*********************************************************************
setselc:process(MOVX, EXTDAT, EXT_PROG_EN,RST)
begin
   SELC <= (MOVX(2) and EXTDAT) or
           (EXT_PROG_EN and not EXTDAT and not RST);
end process setselc;
--*********************************************************************
stretch_movx: process(NX2)
-- Extend MOVX write timing on Port 0 by one clock period for exact
-- compatibility with discrete devices.
begin
   if NX2'event and NX2 = '1' then
      EXTEND_MOVX <= STATD(4) and MOVX(3);
   end if;
end process stretch_movx;
--*********************************************************************
setselmuxoa:process(EXTDAT, EXTEND_MOVX, EXT_PROG_EN, P0DADD, MOVX, CYC)
-- Port 0 output data source control.
-- Concatenate MUX select inputs for benefit of case syntax.
-- Default condition is 110, i.e. output port 0 SFR contents.
begin 
   SELA(2 downto 0) <=((EXTEND_MOVX and CYC(2)) or not EXTDAT)
                      &
                      ((EXTDAT or not EXT_PROG_EN)
                      and not EXTEND_MOVX and not P0DADD)
                      &
                      MOVX(1);
end process setselmuxoa;
--*********************************************************************
muxoa:process(SELA,DPL,FA,ACCDAT,PROGRAM_ADDR,PORT0_SFR)
-- Port 0 output data source multiplexer
begin
   case SELA(2 downto 0) is
       when "000" => OAI <= DPL;
       when "001" => OAI <= FA;
       when "010" => OAI <= ACCDAT;
       when "011" => OAI <= ACCDAT;
       when "100" => OAI <= PROGRAM_ADDR(7 downto 0);
       when "101" => OAI <= PROGRAM_ADDR(7 downto 0);
       when "110" => OAI <= PORT0_SFR;
       when "111" => OAI <= PORT0_SFR;
       when others => OAI <= "XXXXXXXX";
    end case;
end process muxoa;
--*********************************************************************
muxoc:process(SELC,PORT2_SFR,LOCALE)
begin
   case SELC is
       when '0' => L_OC <= PORT2_SFR;
       when '1' => L_OC <=  LOCALE;
       when others => L_OC <= "XXXXXXXX";
    end case;
end process muxoc;
--*********************************************************************
setodrest:process(RXDO, TXDO, NWR, NRD, PORT3_SFR)
-- Wire-OR alternate function outputs onto port 3 output pins.
begin
    L_OD(0) <= PORT3_SFR(0) and RXDO; 
    L_OD(1) <= PORT3_SFR(1) and TXDO; 
    L_OD(2) <= PORT3_SFR(2);
    L_OD(3) <= PORT3_SFR(3);
    L_OD(4) <= PORT3_SFR(4);
    L_OD(5) <= PORT3_SFR(5);
    L_OD(6) <= PORT3_SFR(6) and NWR; 
    L_OD(7) <= PORT3_SFR(7) and NRD; 
end process setodrest;  
--*********************************************************************
movx_strobes:process(NX2)
-- Generate MOVX read and write strobes, between end S6P2 and end S3P2.
begin
    if NX2'event and NX2 = '1' then
       if DIV2CK ='0' then
          if (STATD(3) or CLEAR) = '1' then
             NWR <= '1';
             NRD <= '1';
          elsif ((STATD(6) and CYC(1)) ='1') then
             NWR <= not MOVX(3);
             NRD <= not MOVX(4);
          end if;
        end if;
     end if;
end process movx_strobes;
--*********************************************************************
setae:process(AEEN,PORT0_SFR)
begin
    if AEEN ='1' then
       AE <= "00000000";
    else
       AE <= PORT0_SFR;
    end if;
end process setae;
--********************************************************************* 
setdelays:process(NX2,RST)   
-- delay switch off of drive enables on ports one to three by two clock periods.
begin
   if RST = '1' then
      PORT1_DEL <= "11111111";
      PORT2_DEL <= "11111111";
      PORT3_DEL <= "11111111";
   elsif NX2'event and NX2 = '1' then
      if DIV2CK ='0' then
         PORT1_DEL <= PORT1_SFR;
         PORT2_DEL <= L_OC;
         PORT3_DEL <= L_OD;
      end if;
   end if;
end process setdelays;  
--*********************************************************************
setbe:process(PORT1_SFR,PORT1_DEL)
begin
    BE(0) <= PORT1_SFR(0) and PORT1_DEL(0);
    BE(1) <= PORT1_SFR(1) and PORT1_DEL(1);
    BE(2) <= PORT1_SFR(2) and PORT1_DEL(2);
    BE(3) <= PORT1_SFR(3) and PORT1_DEL(3);
    BE(4) <= PORT1_SFR(4) and PORT1_DEL(4);
    BE(5) <= PORT1_SFR(5) and PORT1_DEL(5);
    BE(6) <= PORT1_SFR(6) and PORT1_DEL(6);
    BE(7) <= PORT1_SFR(7) and PORT1_DEL(7);
end process setbe;  
--********************************************************************* 
setce:process(L_OC,PORT2_DEL,SELC)
begin
    CE(0) <= L_OC(0) and PORT2_DEL(0) and not SELC;
    CE(1) <= L_OC(1) and PORT2_DEL(1) and not SELC;
    CE(2) <= L_OC(2) and PORT2_DEL(2) and not SELC;
    CE(3) <= L_OC(3) and PORT2_DEL(3) and not SELC;
    CE(4) <= L_OC(4) and PORT2_DEL(4) and not SELC;
    CE(5) <= L_OC(5) and PORT2_DEL(5) and not SELC;
    CE(6) <= L_OC(6) and PORT2_DEL(6) and not SELC;
    CE(7) <= L_OC(7) and PORT2_DEL(7) and not SELC;
end process setce;  
--********************************************************************* 
setde:process(L_OD, PORT3_DEL)
begin
    DE(0) <= L_OD(0) and PORT3_DEL(0);
    DE(1) <= L_OD(1) and PORT3_DEL(1);
    DE(2) <= L_OD(2) and PORT3_DEL(2);
    DE(3) <= L_OD(3) and PORT3_DEL(3);
    DE(4) <= L_OD(4) and PORT3_DEL(4);
    DE(5) <= L_OD(5) and PORT3_DEL(5);
    DE(6) <= L_OD(6) and PORT3_DEL(6);
    DE(7) <= L_OD(7) and PORT3_DEL(7);
end process setde;
--********************************************************************* 
muxportsin:process(RMW, LAI_IN, PORT0_SFR, LBI_IN, PORT1_SFR, LCI_IN, PORT2_SFR, LDI_IN, PORT3_SFR)
-- PORT SFR read back MUX:  Port pin values are read unless the 
-- instruction is a read modify write operation in which case the port
-- SFR value is used. 
begin
   case RMW is
      when '0' => PORTA <= LAI_IN;
                  PORTB <= LBI_IN;
                  PORTC <= LCI_IN;
                  PORTD <= LDI_IN;
      when '1' => PORTA <= PORT0_SFR;
                  PORTB <= PORT1_SFR;
                  PORTC <= PORT2_SFR;
                  PORTD <= PORT3_SFR;
      when others => PORTA <= "XXXXXXXX";
                     PORTB <= "XXXXXXXX";
                     PORTC <= "XXXXXXXX";
                     PORTD <= "XXXXXXXX";
   end case;
end process muxportsin;
--********************************************************************* 
end m3s018bo_rtl;
--*********************************************************************