Z8018X Datasheet, PDF (199/326 Pages) Zilog, Inc. – Family MPU

Z 8018x Fam ily
M PU Us e r M anual
184
IO (I/O)
IO addressing mode is used only by I/O instructions. This mode specifies
I/O address (IORQ is 0) and outputs them as follows.
1. An operand is output to A0–A7. The contents of accumulator is
output to A8–A15.
2. The contents of Register B is output to A0 –A7. The contents of
Register C is output to A8–A15.
3. An operand is output to A0–A7. 00H is output to A8–A15 (useful for
internal I/O register access)
4. The contents of Register C is output to A0 –A7. 00H is output to A8–
A15 (useful for internal I/O register access).
UM005001-ZMP0400