Immediate instructions (opcode IMM) allow for 32-bit immediate instructions. They are only meaningful when followed by a Type B instruction. (The two 16-bit immediate values are combined to create one 32-bit value.)
What happens if an interrupt occurs the cycle after an IMM instruction is issued and right before the Type B instruction? Will the immediate value be saved? Are the instructions atomic?
The IMM instruction and the following instruction are considered atomic operations supported by the hardware (i.e., no interrupts will be allowed between them).