Siemens SIMATIC IM 151/CPU Manual page 140

Instruction List
Addressing Examples
Area-Crossing, Memory-Indirect Addressing
For area-crossing, register-indirect addressing, bits 24 to 26 of the address must also con-
tain an area identifier. The address is in the address register.
Area
identifier
P
I
Q
M
DB
DI
L
VL
L B [AR1,P#8.0]
A [AR1,P#32.3]
Addressing Via Parameters
A Parameter
Calculating Pointers
Here are 2 examples of how to calculate pointers:
Example for the sum of the bit addresses 7:
LAR1 P#8.2
A I [AR1,P#10.2]
Result: Input 18.4 is addressed (by adding the byte and bit addresses)
Example for the sum of the bit addresses 7:
L MD 0
LAR1
A I [AR1,P#10.7]
Result: Input 21.4 is addressed (by adding the byte and bit addresses with
carryover)
B-6
Coding Area
Binary Hex.
1000 0000 80I/O area
1000 0001 81Input area
1000 0010 82Output area
1000 0011 83Memory marker area
1000 0100 84Data area
1000 0101 85Instance data area
1000 0110 86Local data area
1000 0111 87Predecessor local data area (access to
local data of the calling block;
see page B-5)
Load byte into ACCU1: The address is calculated from the
pointer value in AR 1 P#8.0
AND operation: The address of the address ID is calculated
from the "pointer value in AR1 P#32.3"
Addressing via parameters
Random pointer, e.g. P#10.5
Description
ET 200S Interface Module IM 151/CPU
A5E00058783-01