Zilog Z80180 - Manual (Page 264)

Z8018x
Family MPU User Manual
248
UM005003-0703
Note 1: (HL) replaces g.
Note 2: (HL) replaces s.
Note 3: If DDH is supplemented as first Op Code for the instructions
which have HL or (HL) as an operand in Table 48, the instructions are
executed replacing HL with IX and (HL) with (IX+d).
ex. 22H : LD (mn), HL
DDH 22H : LD (mn), IX
If FDH is supplemented as 1st Op Code for the instructions which have
HL or (HL) as an operand in Table 48, the instructions are executed
replacing HL with IY and (HL) with (IY+d).
ex. 34H : INC (HL)
FDH 34H : INC (IY+d)
However, JP (HL) and EX DE, HL are exceptions and note the following.
•
If DDH is supplemented as 1st Op Code for JP (HL), (IX) replaces
(HL) as operand and JP (IX) is executed
•
If FDH is supplemented as 1st Op Code for JP (HL), (IY) replaces
(HL) as operand and JP (IY) is executed
•
Even if DDH or FDH is supplemented as 1st Op Code for EX DE,
HL, HL is not replaced and the instruction is regarded as illegal
instruction.