extended/icode.py

   1 #!env python
   2 # vim: set fileencoding=utf8
   3
   4 import base_converter, Trits
   5
   6 class ICode(object):
   7     def __init__(self, s):
   8         if isinstance(s, str):
   9             if s[0] in trit_char:
  10                 # decode trit instrucion code
  11                 decode_code(self, s)
  12             else:
  13                 # decode string instruction
  14                 decode_inst(self, s)
  15         else:
  16             assert "ICode __init__, unable to parse:", s
  17
  18 def decode_code(self, s):
  19     """ Decode:
  20
  21         R-Type:
  22         --------------------------------------------------------
  23         | type(2) | opcode(13) | rs(3) | rt(3) | rd(3) | sa(3) |
  24         --------------------------------------------------------
  25         I-Type:
  26         --------------------------------------------------------
  27         | type(2) | opcode(5) | rs(3) | rt(3) | immediate(14)  |
  28         --------------------------------------------------------
  29         B-Type:
  30         --------------------------------------------------------
  31         | type(2) | opcode(4) | rs(3) | label0(9) | label(9)   |
  32         --------------------------------------------------------
  33         J-Type:
  34         --------------------------------------------------------
  35         | type(2) | opcode(4) | address(21)                    |
  36         --------------------------------------------------------
  37     """
  38
  39     type = int(base_convert(s[0:2], -3, 10))
  40     # R-Type
  41     if type == 0:
  42         self.alu_op = int(base_convert(s[2:15], -3, 10))
  43         self.src1   = int(base_convert(s[15:18], -3, 10))
  44         self.src2   = int(base_convert(s[18:21], -3, 10))
  45         self.dest   = int(base_convert(s[21:24], -3, 10))
  46         self.imdt1  = int(base_convert(s[24:27], -3, 10))
  47
  48         self.imdt2  = 0
  49
  50     # I-Type
  51     elif type == 1:
  52         self.alu_op = int(base_convert(s[2:7], -3, 10))
  53         self.src1   = int(base_convert(s[7:10], -3, 10))
  54         self.src2   = int(base_convert(s[10:13], -3, 10))
  55         self.imdt1  = int(base_convert(s[13:27], -3, 10))
  56
  57         self.dest   = 0
  58         self.imdt2  = 0
  59
  60     # B-Type
  61     elif type == 2:
  62         self.alu_op = int(base_convert(s[2:6], -3, 10))
  63         self.src1   = int(base_convert(s[6:9], -3, 10))
  64         self.imdt1  = int(base_convert(s[9:18], -3, 10))
  65         self.imdt2  = int(base_convert(s[18:27], -3, 10))
  66
  67         self.src2   = 0
  68         self.dest   = 0
  69
  70     # J-Type
  71     elif type == 3:
  72         self.alu_op = int(base_convert(s[2:6], -3, 10))
  73         self.imdt1  = int(base_convert(s[6:27], -3, 10))
  74
  75         self.src1   = 0
  76         self.src2   = 0
  77         self.dest   = 0
  78         self.imdt2  = 0
  79
  80     # Uknown type
  81     else:
  82         raise DecodeError("invalid type code = %s" % (type, ))
  83
  84