armiu_exstg.vhd

ARM7的源代码

        -- $(/del)

        t.newcpsr.ex.n := t.cpsr.ex.n;
        t.newcpsr.ex.z := t.cpsr.ex.z;
        t.newcpsr.ex.c := r.pctrl.rs.rs_shieftcarryout;
        
      when type_arm_sub =>

        --
        -- $(del)
        -- arm@4.1.49:         
        --if ConditionPassed(cond) then
        -- Rd = Rn - shifter_operand
        -- if S == 1 and Rd == R15 then
        --  CPSR = SPSR
        -- else if S == 1 then
        --  N Flag = Rd[31]
        --  Z Flag = if Rd == 0 then 1 else 0
        --  C Flag = NOT BorrowFrom(Rn - shifter_operand)
        --  V Flag = OverflowFrom(Rn - shifter_operand)
        -- $(/del)
        
        t.newcpsr.ex.n := t.cpsr.ex.n;
        t.newcpsr.ex.z := t.cpsr.ex.z;
        t.newcpsr.ex.c := not t.cpsr.ex.c;
        t.newcpsr.ex.v := t.cpsr.ex.v;
        
      when type_arm_add =>
        
        --
        -- $(del)
        -- arm@4.1.3:         
        --if ConditionPassed(cond) then
        --  Rd = Rn + shifter_operand
        -- if S == 1 and Rd == R15 then
        --  CPSR = SPSR
        -- else if S == 1 then
        --  N Flag = Rd[31]
        --  Z Flag = if Rd == 0 then 1 else 0
        --  C Flag = CarryFrom(Rn + shifter_operand)
        --  V Flag = OverflowFrom(Rn + shifter_operand)
        -- $(/del)

        t.newcpsr.ex.n := t.cpsr.ex.n;
        t.newcpsr.ex.z := t.cpsr.ex.z;
        t.newcpsr.ex.c := t.cpsr.ex.c;
        t.newcpsr.ex.v := t.cpsr.ex.v;        

      when type_arm_rsb =>
        
        -- Reverse Subtract
        -- $(del)
        -- arm@4.1.36:         
        --if ConditionPassed(cond) then
        -- Rd = shifter_operand - Rn
        -- if S == 1 and Rd == R15 then
        --  CPSR = SPSR
        -- else if S == 1 then
        --  N Flag = Rd[31]
        --  Z Flag = if Rd == 0 then 1 else 0
        --  C Flag = NOT BorrowFrom(shifter_operand - Rn)
        --  V Flag = OverflowFrom(shifter_operand - Rn)
        -- $(/del)

        t.newcpsr.ex.n := t.cpsr.ex.n;
        t.newcpsr.ex.z := t.cpsr.ex.z;
        t.newcpsr.ex.c := not t.cpsr.ex.c;
        t.newcpsr.ex.v := t.cpsr.ex.v;
        
      when type_arm_adc =>

        -- Add with Carry
        -- $(del)
        -- arm@4.1.2:         
        --if ConditionPassed(cond) then
        -- Rd = Rn + shifter_operand + C Flag
        --if S == 1 and Rd == R15 then
        -- CPSR = SPSR
        --else if S == 1 then
        -- N Flag = Rd[31]
        -- Z Flag = if Rd == 0 then 1 else 0
        -- C Flag = CarryFrom(Rn + shifter_operand + C Flag) 
        -- V Flag = OverflowFrom(Rn + shifter_operand + C Flag)
        -- $(/del)

        t.newcpsr.ex.n := t.cpsr.ex.n;
        t.newcpsr.ex.z := t.cpsr.ex.z;
        t.newcpsr.ex.c := t.cpsr.ex.c;
        t.newcpsr.ex.v := t.cpsr.ex.v;

      when type_arm_sbc =>

        -- Subtract with Carry
        -- $(del)
        -- arm@4.1.38:         
        --if ConditionPassed(cond) then
        -- Rd = Rn - shifter_operand - NOT(C Flag)
        -- if S == 1 and Rd == R15 then
        --  CPSR = SPSR
        -- else if S == 1 then
        --  N Flag = Rd[31]
        --  Z Flag = if Rd == 0 then 1 else 0
        --  C Flag = NOT BorrowFrom(Rn - shifter_operand - NOT(C Flag))
        --  V Flag = OverflowFrom(Rn - shifter_operand - NOT(C Flag))
        -- $(/del)

        t.newcpsr.ex.n := t.cpsr.ex.n;
        t.newcpsr.ex.z := t.cpsr.ex.z;
        t.newcpsr.ex.c := not t.cpsr.ex.c;
        t.newcpsr.ex.v := t.cpsr.ex.v;
        
      when type_arm_rsc =>
        
        -- Reverse Subtract with Carry
        -- $(del)
        -- arm@4.1.37:         
        --if ConditionPassed(cond) then
        -- Rd = shifter_operand - Rn - NOT(C Flag)
        -- if S == 1 and Rd == R15 then
        --  CPSR = SPSR
        -- else if S == 1 then
        --  N Flag = Rd[31]
        --  Z Flag = if Rd == 0 then 1 else 0
        --  C Flag = NOT BorrowFrom(shifter_operand - Rn - NOT(C Flag))
        --  V Flag = OverflowFrom(shifter_operand - Rn - NOT(C Flag))
        -- $(/del)

        t.newcpsr.ex.n := t.cpsr.ex.n;
        t.newcpsr.ex.z := t.cpsr.ex.z;
        t.newcpsr.ex.c := not t.cpsr.ex.c;
        t.newcpsr.ex.v := t.cpsr.ex.v;
        
      when type_arm_strhb =>
      when type_arm_str1 |
           type_arm_str2 |
           type_arm_str3 =>
      when type_arm_ldrhb =>
      when type_arm_ldr1 => null; 
      when type_arm_undefined => null;
      when type_arm_stm => null; 
      when type_arm_ldm => null; 
      when type_arm_b => null;   
      when type_arm_swi => null; 
      when others => null;
    end case;
    

    -- reset
    if ( rst = '0' ) then
      v.cpsr.ex.n := '0';
      v.cpsr.ex.z := '0';
      v.cpsr.ex.c := '0';
      v.cpsr.ex.v := '0';

      v.cpsr.wr.i := '0';
      v.cpsr.wr.f := '0';
      v.cpsr.wr.t := '0';
      
      v.cpsr.wr.mode := APM_SVC;     -- change
    end if;
    
    -- pipeline propagation
    t.o.pctrl_r := r.pctrl;
    t.o.toDM_pctrl_v := v.pctrl;

    -- pipeline flush
    if not (t.commit = '1') then
      t.o.toDM_pctrl_v.valid := '0';
    end if;
    
    t.o.cpsr_r := r.cpsr;
    t.o.alures_v := t.result;
    t.o.toIM_branch_v := '0';
    t.o.flush_v := '0';
    
    case r.pctrl.ex.exop_data_src is
      when apc_datasrc_aluout => t.o.toDM_pctrl_v.data1 := t.result;
-- todo: check obsolete apd_datasrc_op1
      --when apc_datasrc_op1    => t.o.toDM_pctrl_v.data1 := r.pctrl.data1;
      when apc_datasrc_buf    => t.o.toDM_pctrl_v.data1 := r.buf;
      when apc_datasrc_none => 
      when others => null;
    end case;
    
    if apc_is_strdata(r.pctrl) then
      case r.pctrl.me.meop_param.size is
        when lmd_byte => t.o.toDM_pctrl_v.data2 := r.pctrl.data2(7 downto 0) & r.pctrl.data2(7 downto 0) & r.pctrl.data2(7 downto 0) & r.pctrl.data2(7 downto 0);
        when lmd_half => t.o.toDM_pctrl_v.data2 := r.pctrl.data2(15 downto 0) & r.pctrl.data2(15 downto 0);
        when others => 
      end case;
    end if;
    
    case r.pctrl.ex.exop_buf_src is
      when apc_exbufsrc_aluout => v.buf := t.result;
      when apc_exbufsrc_op1    => v.buf := r.pctrl.data1;
      when apc_exbufsrc_none => 
      when others => null;
    end case;

    -- branching
    if apc_is_valid(r.pctrl) then
      if apc_is_branch(r.pctrl) then
        t.o.flush_v := '1';
        if not apc_is_memload(r.pctrl) then
          if t.commit = '1' then
            t.o.toIM_branch_v := '1';
          end if;
        end if;
      end if;
    end if;

    if apc_is_valid(r.pctrl) then
      if r.pctrl.wr.wrop_trap.trap = '1' then
        t.o.flush_v := '1';
        case r.pctrl.wr.wrop_trap.traptype is
          when apm_trap_reset    =>
            
-- $(del)
-- R14_svc = UNPREDICTABLE value
-- SPSR_svc = UNPREDICTABLE value
-- CPSR[4:0] = 0b10011 /* Enter Supervisor mode */
-- CPSR[5] = 0 /* Execute in ARM state */
-- CPSR[6] = 1 /* Disable fast interrupts */
-- CPSR[7] = 1 /* Disable normal interrupts */
-- if high vectors configured then
-- PC = 0xFFFF0000
-- else
-- PC = 0x00000000
-- $(/del)
          
          when apm_trap_undef =>

-- $(del)
-- R14_und = address of next instruction after the undefined instruction
-- SPSR_und = CPSR
-- CPSR[4:0] = 0b11011 /* Enter Undefined mode */
-- CPSR[5] = 0 /* Execute in ARM state */
-- /* CPSR[6] is unchanged */
-- CPSR[7] = 1 /* Disable normal interrupts */
-- if high vectors configured then
-- PC = 0xFFFF0004
-- else
-- PC = 0x00000004
-- $(/del)
          
          when apm_trap_swi      =>

-- $(del)
-- R14_svc = address of next instruction after the SWI instruction
-- SPSR_svc = CPSR
-- CPSR[4:0] = 0b10011 /* Enter Supervisor mode */
-- CPSR[5] = 0 /* Execute in ARM state */
-- /* CPSR[6] is unchanged */
-- CPSR[7] = 1 /* Disable normal interrupts */
-- if high vectors configured then
-- PC = 0xFFFF0008
-- else
-- PC = 0x00000008
-- $(/del)
          
          when apm_trap_prefch =>

-- $(del)
-- R14_abt = address of the aborted instruction + 4
-- SPSR_abt = CPSR
-- CPSR[4:0] = 0b10111 /* Enter Abort mode */
-- CPSR[5] = 0 /* Execute in ARM state */
-- /* CPSR[6] is unchanged */
-- CPSR[7] = 1 /* Disable normal interrupts */
-- if high vectors configured then
-- PC = 0xFFFF000C
-- else
-- PC = 0x0000000C
-- $(/del)
          
          when apm_trap_dabort   =>

-- $(del)
-- R14_abt = address of the aborted instruction + 8
-- SPSR_abt = CPSR
-- CPSR[4:0] = 0b10111 /* Enter Abort mode */
-- CPSR[5] = 0 /* Execute in ARM state */
-- /* CPSR[6] is unchanged */
-- CPSR[7] = 1 /* Disable normal interrupts */
-- if high vectors configured then
-- PC = 0xFFFF0010
-- else
-- PC = 0x00000010
-- $(/del)

          when apm_trap_irq      =>

-- $(del)
-- R14_irq = address of next instruction to be executed + 4
-- SPSR_irq = CPSR
-- CPSR[4:0] = 0b10010 /* Enter IRQ mode */
-- CPSR[5] = 0 /* Execute in ARM state */
-- /* CPSR[6] is unchanged */
-- CPSR[7] = 1 /* Disable normal interrupts */
-- if high vectors configured then
-- PC = 0xFFFF0018
-- else
-- PC = 0x00000018
-- $(/del)

          
          when apm_trap_fiq      =>

-- $(del)
-- R14_fiq = address of next instruction to be executed + 4
-- SPSR_fiq = CPSR
-- CPSR[4:0] = 0b10001 /* Enter FIQ mode */
-- CPSR[5] = 0 /* Execute in ARM state */
-- CPSR[6] = 1 /* Disable fast interrupts */
-- CPSR[7] = 1 /* Disable normal interrupts */
-- if high vectors configured then
-- PC = 0xFFFF001C
-- else
-- PC = 0x0000001C
-- $(/del)

          
          when others            => 
        end case;
      end if;
    end if;

    
    t.o.toDM_pctrl_v.ex.ex_cpsr := r.cpsr;

    if i.pstate.hold_r.hold = '0' then
      v.pctrl := i.fromRS_pctrl_v;
      if apc_is_valid(r.pctrl) then
        if t.commit = '1' then
          v.cpsr := t.newcpsr;
        end if;
      end if;
      if i.fromWR_cpsrset_v = '1' then
        v.cpsr := i.fromWR_cpsr_v;
      end if;
    end if;

    t.o.cpsr_v := v.cpsr;

    c <= v;

    o <= t.o;
    
    -- pragma translate_off
    vdbg := rdbg;
    vdbg.dbg := t;
    vdbg.dbg.dbgaluop := adg_todbgaluop(r.pctrl.ex.exop_aluop);
    cdbg <= vdbg;
    -- pragma translate_on  
    
  end process p0;
    
  pregs : process (clk, c)
  begin
    if rising_edge(clk) then
      r <= c;
      -- pragma translate_off
      rdbg <= cdbg;
      -- pragma translate_on
    end if;
  end process;
  
end rtl;