Editing Machine code (section)

===MIPS===
The [[MIPS architecture]] provides a specific example for a machine code whose instructions are always 32 bits long.<ref name="Harris_2007"/>{{Rp|299}} The general type of instruction is given by the ''op'' (operation) field, the highest 6 bits. J-type (jump) and I-type (immediate) instructions are fully specified by ''op''. R-type (register) instructions include an additional field ''funct'' to determine the exact operation. The fields used in these types are:

    6      5     5     5     5      6 bits
 [  op  |  rs |  rt |  rd |shamt| funct]  R-type
 [  op  |  rs |  rt | address/immediate]  I-type
 [  op  |        target address        ]  J-type

''rs'', ''rt'', and ''rd'' indicate register operands; ''shamt'' gives a shift amount; and the ''address'' or ''immediate'' fields contain an operand directly.<ref name="Harris_2007"/>{{Rp|299–301}}

For example, adding the registers 1 and 2 and placing the result in register 6 is encoded:<ref name="Harris_2007"/>{{Rp|554}}

 [  op  |  rs |  rt |  rd |shamt| funct]
     0     1     2     6     0     32     decimal
  000000 00001 00010 00110 00000 100000   binary

Load a value into register 8, taken from the memory cell 68 cells after the location listed in register 3:<ref name="Harris_2007"/>{{Rp|552}}

 [  op  |  rs |  rt | address/immediate]
    35     3     8           68           decimal
  100011 00011 01000 00000 00001 000100   binary

Jumping to the address 1024:<ref name="Harris_2007"/>{{Rp|552}}

 [  op  |        target address        ]
     2                 1024               decimal
  000010 00000 00000 00000 10000 000000   binary