These instructions contain the operation code, 3 register addresses, and a function code.
| op | rs | rt | rd | fc |
| 4 | 3 | 3 | 3 | 3 |
These instructions contain the operation code, 2 register addresses, and an immediate value.
| op | rs | rt | immediate |
| 4 | 3 | 3 | 6 |
This type is the same as M-type, but with a 1-bit function code at bit 8.
| op | rs | F | immediate |
| 4 | 3 | 1 | 8 |
These instructions contain the operation code and a target address. The address passed is only the low-order 12 bits, and the leftmost nybble of the full address is assumed to be the same as that of the PC.
| op | address |
| 4 | 12 |