(nn+1) <- H, (nn) <- L
The contents of the low-order portion of register pair HL (Register L) are loaded to memory address (nn), and the contents of the high-order portion of HL (Register H) are loaded to the next highest memory address (nn + 1). The first n operand after the op code is the low-order byte of nn.
If register pair HL contains $483A, then upon execution of
address $B229 contains $3A and address $B22A contains $48.