The contents of the user stack pointer are transferred either to or from the specified address register.
----------------------------------------------------------------- |15 |14 |13 |12 |11 |10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |---|---|---|---|---|---|---|---|---|---|---|---|---|-----------| | 0 | 1 | 0 | 0 | 1 | 1 | 1 | 0 | 0 | 1 | 1 | 0 |dr | REGISTER | ----------------------------------------------------------------- "REGISTER" indicates the number of address register. dr specifies move direction: 0->An to USP 1->USP to An