I read here that if the Z80 encounters e.g. multiple 0xdd prefixes in sequence, for each 0xxdd except the last it acts almost like a NOP, but does not allow interrupts to occur immediately after "executing" the discarded byte.
My question is: If an instruction is prefixed by 0xdd, but not affected by the prefix (i.e. it does not act on the HL register), does the 0xdd also act like a NOP and disallow interrupts? Or is it a simple NOP in this case? Or does it not have an effect at all? The documentation I could find was not very clear on this.