CPUs for M7-400
11-40 S7-400, M7-400 Programmable Controllers Module Specifications
A5E00069467-07
11.5 I/O Addresses, Main Memory and InterruptAssignments
Introduction
This section gives you detailed information, in the form of a table, on the I/O
address space assignment, main memory and interrupt assignments of the CPUs.

Memory Assignment

The main memory is assigned as follows in the M7-400:
Table 11-8 Main Memory Assignment
Address Content
1 MB to 15 MB User memory area
15 MB to 16 MB PROFIBUS DP*), otherwise free
E 8000H to F FFFFH BIOS
E 0000H to E 7FFFH Free (32 K)
D 0000H to D FFFFH Free (64 K)
C F000H to C FFFFH Free (4 K)
C C000H to C EFFFH Memory card, otherwise free (12 K)
C 8000H to C BFFFH Free (16 K)
C 0000H to C 7FFFH Shadow VGA BIOS (32 K)
A 0000H to B FFFFH VGA (128 K)
0 0000H to 9 FFFFH 640 K system area
*) If the interface submodule IF 964-DP is not plugged in the preferred slot (see Table 13-3
on page 13-4)

Keeping Memory Areas Free

The memory areas that are not always marked as “free” should be kept free when
using a memory manager.

SRAM Area

The size of the SRAM with battery backup is 64 Kbytes (net for data blocks
56 Kbytes). If the battery is removed and inserted again when there is no power
connected, the SRAM content will be lost. This is indicated by the BAF LED.