Detailed descriptions   
16.4 I/O Address Areas 
  SIMATIC IPC427C 
142  Operating Instructions, 04/2009, A5E02414743-01 
16.4.7  SRAM address register 
 
The battery-buffered SRAM uses a 2 MB memory address area, which can be read via the 
PCI register. 
Meaning of the bits 
 
SRAM address register 
PCI register address: 
SRAM base address register 
PCI register content: 
SRAM memory address (default) 
Length of the memory area 
8010 2010h  9040 0000h 
Address is assigned dynamically 
(depending on device) 
20 0000h