[0x00400000] 0x34080fa5 ori $8, $0, 4005 ori $8,$0,0x0FA5
Yes. How could you miss? The last 16 bits are the immediate operand.
Below is the machine code for the instruction. In the third line the bits have been grouped into fields that have various functions.
Look this over to get an idea of how it works:
Documentation for the MIPS shows the fields for each instruction. The designers of the MIPS processor decided what information was needed in a machine instruction and how to arrange it.
Other machine instructions follow other formats. See the documentation or a MIPS green card.
3 4 0 8 0 f a 5 -- machine instruction in hex 0011 0100 0000 1000 0000 1111 1010 0101 -- machine instruction in bits 001101 00000 01000 0000 1111 1010 0101 -- fields of the instruction ori $0 $8 0 f a 5 opcode oper- dest immediate operand -- meaning of the fields and reg. reg. ori $8, $0, 0x0fa5 -- assembly language instruction (Notice that the register numbers are not in the same order as they are in the machine instruction).
Here is another ori instruction.
The patterns
that specify the operand register, the destination register,
and the immediate operand are blank.
Fill in the blanks
with bit patterns
so the operand register is $10 , the destination register is
$9 ,
and the immediate operand is 0xAFF0
001101
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
ori $10 $9 a f f 0
operand dest immediate operand
reg. reg.