MIPS (by nazirul anwar)

 Branch Addressing

}  Branch instructions specify

       -Opcode, two registers, target address

}  Most branch targets are near branch

-Forward or backward

 Decoding Machine Language

}  Refer to MIPS Reference Data

}  What is the assembly language statement corresponding to this machine instruction?

                        00af8020hex

}  Step 1: convert hex to binary to find the op fields. Set the bit based on the R-format field (since it has the most fields available of all format:

Bits:  31 28 26      20  16          10    5

            0000 0000 1010 1111 1000 0000 0010 0000

}  Step 2: determine the operation,  when bits 31-26 are 000000 and bit 5-0 has a value, it is R-format. Convert the funct value into hex.

}  You will get 20hex. Look into the reference for opcode/funct column with value 0/20hex. The pattern represents add instruction.

}  Step 3: Decode the rest of the instruction by looking the field of values.

Bits:31 28 26   20  16      10    5

            000000 00101 01111 10000 00000 100000

                  0  $a1   $t7  $s0     0     add

}  Step 4: Rearrange the values into an assembly instruction

                  add $s0, $a1, $t7