C509-L_97 SIEMENS [Siemens Semiconductor Group], C509-L_97 Datasheet - Page 65

• Manufacturer Part Number: C509-L_97
• Description: 8-Bit CMOS Microcontroller
• Manufacturer: SIEMENS [Siemens Semiconductor Group]

Figure 4-4
Write Page Address to Port 2
“MOV P2,pageaddress” will write the page address to Port 2 and the XPAGE-Register.
When external RAM is to be accessed in the XRAM address range (F400 H - FFFF H ), XRAM has
to be disabled. When additional external RAM is to be addressed in an address range
(F400 H ) XRAM may remain being enabled and there is no need to overwrite XPAGE by a second
move.
Semiconductor Group
Write to Port 2
XPAGE
Port 0
Port 2
4-13
XRAM
External Bus Interface
MCB02112
Address/Data
Page Address
1997-10-01
C509-L
XRAM