SAB80C515A-5 Datasheet, PDF (18/108 Pages) Siemens Semiconductor Group – 8-Bit CMOS Single-Chip Microcontroller Family

Memory Organization
Figure 3-3
Write Page Address to XPAGE
The page address is only written to XPAGE-register. Port 2 is available for addresses or I/O-Data.
See figure 3-4 to see what happens when Port 2 is used as I/O-Port.
Semiconductor Group
3-11