This page describes the reserved, unimplemented instruction 'LM'
Some PAIR combinations such as LM are reserved ("scrounged" away before decoding). They are mapped to NOP, but this is subject to change for application specific uses or instruction set extensions. The instruction that would move L into M would involve an instruction fetch and two additional data fetches in the same instruction cycle. The opcode which corresponds to this instruction is remapped to NOP or to other opcodes/instructions.