Subversion Repositories tinycpu

PREFIX = "MemIn <= x\"";

SUFFIX = "\";";

SEPERATOR = "\n";

class OpcodeByte1

  attr_accessor :op, :register, :cond;

  def to_hex

    s = (op << 4 | register.number << 1 | cond).to_s(16);

    if s.length == 1

      "0"+s;

    elsif s.length == 0

      "00";

    else

      s

    end

  end

end

class OpcodeByte2

  attr_accessor :cond, :reg2, :useextra, :reg3;

  def to_hex

    s=(cond << 8 | reg2.number << 5 | useextra << 4 | reg3.number).to_s(16);

    if s.length == 1

      "0"+s;

    elsif s.length==0

      "00";

    else

      s;

    end

  end

end

class Register8

  attr_accessor :number

  def initialize(num)

        @number=num

  end

end

class OpcodeOption

  attr_accessor :number

  def initialize(num)

    @number=num;

  end

end

$iftr = 0; #0 for no condition, 1 for if TR, 2 for if not TR

$useextra = 0;

def mov_r8_imm8(reg,imm)

  o = OpcodeByte1.new();

  o.op = 0;

  o.register=reg;

  if $iftr<2 then

    o.cond=$iftr;

  else

    raise "if_tr_notset is not allowed with this opcode";

  end

  puts PREFIX + o.to_hex + imm.to_s(16) + SUFFIX;

  puts SEPERATOR;

end

def mov_rm8_imm8(reg,imm)

  o=OpcodeByte1.new();

  o.op=1;

  o.register=reg;

  if $iftr<2 then

    o.cond=$iftr;

  else

    raise "if_tr_notset is not allowed with this opcode";

  end

  puts PREFIX + o.to_hex + imm.to_s(16) + SUFFIX;

  puts SEPERATOR;

end

def

def mov(arg1,arg2)

  if arg1.kind_of? Register8 and arg2.kind_of? Integer and arg2<0x100 then

    mov_r8_imm8 arg1,arg2

  elsif arg1.kind_of? Array and arg2.kind_of? Integer and arg2<0x100 then

    if arg1.length>1 or arg1.length<1 then

      raise "memory reference is not correct. Only a register is allowed";

    end

    reg=arg1[0];

    mov_rm8_imm8 reg, arg2

  else

    raise "No suitable mov opcode found";

  end

end

def if_tr_set

  $iftr = 1

  yield

  $iftr = 0

end

r0=Register8.new(0)

r1=Register8.new(1)

r2=Register8.new(2)

r3=Register8.new(3)

r4=Register8.new(4)

r5=Register8.new(5)

sp=Register8.new(6)

ip=Register8.new(7)

#test code follows. Only do it here for convenience.. real usage should prefix assembly files with `require "asm.rb"`

if_tr_set{

  mov r1,0x10

}

mov r1,0x20

mov [r1], 0x50