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> SETUSRP mn Enter User Interrupt Rabbit 4000 Instruction

> Opcode | Instruction | Clocks | Operation
> ED B5 n m | SETUSRP mn | 15 (2,2,2,2,1,3,3) | SU = {SU[7:2],01} (SP - 1) = m (SP - 2) = n SP = SP - 2

> Flags | ALTD | IOI/IOE
> S | Z | L/V | C | F | R | SP | S | D
> - | - | - | - |  |  |  |  |

> #### Description

> Sets the current processor mode by setting SU bit 1 to zero and bit 0 to one.

> The System/User Mode Register, SU, is an 8-bit register that forms a stack of the current processor mode and the previous 3 modes.

> This instruction is used to handle user mode interrupts in system/user mode.

> This is a chained-atomic instruction, meaning that an interrupt cannot take place between this instruction and the instruction following it.

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