r <- (IY+d)
The operand (IY+d) loads the contents of Index Register IY summed with two’s-complement displacement integer, d, to register r, in which r identifies registers A, B, C, D, E, H, or L, assembled as follows in the object code:
If Index Register IY contains the number $25AF, the instruction
allows the calculation of the sum $25AF+$19, which points to memory location $25C8. If this address contains byte $39, the unstruction results in Register B also containing $39.