Addressing The Spc 4-2 - Siemens SIMATIC NET SPC 4-2 LF Manual

4.1

Addressing the SPC 4-2

From the user perspective, the 3-Kbyte internal dual-port RAM and the internal
latches occupy a 1-Kbyte address space. Parts of the internal RAM are located
directly in the address range of the microprocessor, the other parts can be
addressed using a window mechanism, see Figure 4-1
Micro-
processor
1FFH
200H
2FFH
300H
3FFH
Figure 4-1
20
0H
512 bytes
general
parameters,
SAP list
256 bytes
memory window
256 bytes
controller
parameters
Addressing the Internal 3-Kbyte RAM
SPC42
PROFIBUS Controller SPC 4®-2 LF
0H
3 kB RAM
0xBFFH
Latches
C79000-G8976-C157-3