Yes, as long as the remaining 16 bits are enough to specify the machine operation.
Some machine instructions contain a 16 bit operand. The second operand is contained in a register. An operand that is directly encoded as part of a machine instruction is called an immediate operand.
For example, here is one of the instructions from the previous example program:
address machine code assembly code 0x00400000 0x34080002 ori $8,$0,0x2
The last 16 bits (four hex characters) of the machine instruction contain the operand 0x0002. The assembly language instruction can just say "0x2". The assembler creates a pattern padded with zeros to fill 16 bits.
| OR Operation on Bits | ||||
|---|---|---|---|---|
| first operand | 0 | 0 | 1 | 1 |
| second operand | 0 | 1 | 0 | 1 |
| result | 0 | 1 | 1 | 1 |
The machine instruction tells the ALU to perform a
bitwise OR between the contents of register
$0 and the immediate operand 0x0002.
The result is put in register $8 .
A bitwise operation is where a logical operation is performed on the bits of each column of the operands. The result in each column depends only on the bits in that column. Here is the bitwise OR between two 8-bit patterns:
0110 1100 operand 0101 0110 operand 0111 1110 result
$0 ?