Program Memory/Program Cache Memory - Mitsubishi Electric MELSEC iQ-R-R00CPU User Manual

Program memory/program cache memory

The program memory and program cache memory store necessary programs for the CPU module to perform operations. At
the following timing, data in the program memory is transferred to the program cache memory
performed.
*1 This memory is used for program operations.
• Powered-on
• Reset operation
Application
The program memory and program cache memory store execution programs of program files and FB (function block) files.
Execution programs include instruction codes, statements, and notes.
Data to be allocated
*1
The file header area and the execution program area (including reserved area for online change) that exist in program files
and FB files are allocated to the program memory.
*1 Depending on the model and firmware version of the CPU module, the file header area is allocated to the data memory. ( Page 94
Destination of the file header area)
Data allocation and procedure of read/write operations
The following figure shows the data allocation of the program memory and program cache memory and the procedure of read/
write operations from/to the programmable controller.
Engineering tool
Program file
File header area
Execution program area
+
Reserved area for
online change
Program restoration
information area
*1 Program restoration information includes the information required to read a program from the programmable controller with the
engineering tool.
(1) When data is written to the programmable controller, the file header, execution program, and reserved area for online change are written to the program
cache memory, and program restoration information is written to the data memory.
(2) After being written to the program cache memory, the data is automatically transferred to the program memory.
(3) When data is read from the programmable controller, the file header, execution program, and reserved area for online change are read from the program
memory, and the program restoration information is read from the data memory.
(4) After the CPU module is powered off and on or is reset, the data in the program memory is transferred to the program cache memory and operations are
executed.
*2 Depending on the model and firmware version of the CPU module, the destination of the file header area is the data memory. (
Page 94 Destination of the file header area)
For read/write operations from/to the programmable controller, refer to the following.
 GX Works3 Operating Manual
Inside of the CPU module
(1)
*2
(3)
Program cache
memory
(1)
(3)
Program memory
(1)
*1
(3)
Data memory
*1
and an operation is
(2)
(4)
When the data is written to the
programmable controller
When the data is read from the
programmable controller
When the CPU module is powered
off and on or is reset
3 MEMORY CONFIGURATION OF THE CPU MODULE
3.1 Memory Configuration
3
93