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5.2 High Performance Model QCPU, Process CPU, Redundant CPU, Universal Model QCPU
5.2.3 Program cache memory (Universal model QCPU only)
5
MEMORIES AND FILES USED IN CPU MODULE
5.2.3 Program cache memory (Universal model QCPU only)
(1) Program cache memory overview
The Universal model QCPU cannot boot programs from the standard ROM to the
program memory.
The Universal model QCPU transfers programs stored in the program memory to the
program cache memory to perform operations. (
(3) in this section)
The following shows the transfer timing from the program memory to the program
cache memory.
• During initial processing when the programmable controller is powered ON
• During initial processing when the reset operation of the CPU module is
performed
Figure 5.17 shows the flow of program operations.
Note3
Figure 5.17 Flow of program operations
Note3
High
Performance
Process
Redundant
Note5.3
<Drive3>
Standard RAM
(SRAM)
Power ON/RESET
Initial processing
(Transfers contents of the
program memory to the
program cache memory)
I/O module refresh
processing
Program operation
processing
END processing
<Drive4>
Standard ROM
(Flash ROM)
<Drive0>
Program
memory
(Flash ROM)
2) Operation processing
1) Transfer
Universal model QCPU
Operation processing of
program A
Operation processing of
program B
Operation processing of
program C
Execution order can be changed.
CPU shared
memory
Program
cache
memory
(SRAM)
Since the High Performance model QCPU, Process CPU and Redundant CPU do not use the
program cache memory, it is not necessary to be conscious of this description.
High
Performance
Process
Redundant
