Flash Memory Operation - Emerson PACSystems RX3i User Manual

PACSystems™ RX3i and RSTi-EP CPU Reference Manual
GFK-2222AK
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4.6

Flash Memory Operation

The CPU stores the current configuration and application in user memory (either
battery-backed RAM or non-volatile user memory, depending on the CPU model). You
can also store the Logic, Hardware Configuration, and Reference Data into non-volatile
flash memory. The PACSystems CPU provides enough flash memory to hold all of user
space, all reference tables that aren't counted against user space, and any overhead
required. For details on which items count against user memory space, refer to A-4.
By default, the CPU reads program logic and configuration, and reference table data from
user memory at power-up. However, logic/configuration and reference tables can each
be configured to always read from flash or conditionally read from flash. To configure
these parameters in the programming software, select the CPU's Settings tab in
Hardware Configuration.
If logic/configuration and/or reference tables are configured for conditional power-up
from flash, these items are restored from flash to user memory when the user memory is
corrupted or was not preserved (for example, the memory backup battery or Energy Pack
is not installed or not operational). If logic/configuration and/or reference memory are
configured for conditional power-up from flash and user memory has been preserved, no
flash operation will occur.
If logic/configuration and/or reference tables are configured to always power up from
flash, these items are restored from flash to user memory regardless of the state of the
user memory.
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In addition to configuring where the CPU obtains logic, configuration, and data during
power-up, the programming software provides the following flash operations:
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Flash read and write operations copy the contents of flash memory or user memory as
individual files. The programming software displays the progress of the copy operation
and allows you to cancel a flash read or write operation during the copy process instead of
waiting for the entire transfer process to complete. The entire user memory image must
be successfully transferred for the flash copy to be considered successful. If an entire
CPU Operation
Validation of sweep mode and program scheduling mode selections
Validation of references used by programs with the actual configured sizes
Re-initialization of data areas for external blocks and standalone C programs
Clearing of non-retentive memory
Note: If any component (logic/configuration or reference tables) is read from
flash, OEM-mode and passwords are also read from flash.
Write a copy of the current configuration, application program, and reference tables
(excluding overrides) to flash memory. Note that a write-to-flash operation causes
all components to be stored to flash.
Read a previously stored configuration and application program, and/or reference
table values from flash into user memory.
Verify that flash and user memory contain identical data.
Clear flash contents.
Section 4
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