Siemens SIMATIC TI545, Системное руководство

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Starting Up the TI555 System
6-4
TI545/TI555 System Manual
6.2 TI545 CPU Memory Configuration
The TI545 CPU memory is user configurable. The actual ranges of memory
types depend upon how the memory has been configured. Ranges for
memory types are listed in Table 6-1.
You can increase the memory allocated to a particular memory type, a block
at a time, up to the maximum listed in Table 6-1. Block sizes vary with the
memory type as shown in Table 6-1.
Some overhead is associated with certain memory types. For example, each
K byte of L-memory uses a total of 3K bytes of system memory. Each
timer/counter uses 5 bytes of system memory. A drum uses 48 bytes.
When you increase L-memory by one block, from 16K bytes to 20K bytes,
system memory reserved for L-memory increases from 48K bytes to
60K bytes. When you increase the number of drums by one block, from 64 to
128, system memory reserved for drums increases from 3K bytes to
6K bytes.
Up to 192K bytes of configurable system memory are available on the TI545
CPU. You cannot configure all memory types to their maximum allocation
size simultaneously. For example, if V-memory is configured to 177K bytes,
then S memory cannot be configured to 176K bytes because the 192K bytes
of system memory would be exceeded.
Refer to your TISOFT manual and SIMATIC TI505 Programming Reference
manual for additional information on memory configuration and configuring
I/O.
Table 6-1 TI545-1102 CPU Memory Configuration
Memory Type
Block
Allocation
Size
Memory
Required
per Block
Minimum
Size
Maximum
Size
Total Memory
Required for
Maximum Size
Ladder (L) 1K bytes 3K bytes 1K bytes 59K bytes 177K bytes
Variable (V) 1K bytes 1K bytes 1K bytes 177K bytes 177K bytes
Constant (K) 1K bytes 1K bytes 0K bytes 176K bytes 176K bytes
Special (S) 1K bytes 1K bytes 0K bytes 176K bytes 176K bytes
User (U) 1K bytes 1K bytes 0K bytes 176K bytes 176K bytes
Timer 1024* 5K bytes 1024* 4096 20K bytes
Drum 64* 3K bytes 64 512 24K bytes
Shift Register 1024* 1K bytes 1024* 3072 3K bytes
Table Move 1024* 2K bytes 1024* 3072 6K bytes
One Shot 1024* 1K bytes 1024* 7168 7K bytes
*Number per block.
Memory
Configuration
Maximum
Configurable
Memory