5.6.5.1. Software and Data Base Loading (Flash Loading Concept) 
The software loading is done by the EPROM extender program. The EPROM
extender program is factory-preloaded, but can be reloaded on site by
means of the CDGM program.
When PBXXX is powered-up or restarted, the bootstrap EPROM checks
if the EPROM extender program on the board is still present. When no
extender is available, the PBXXX will wait for the CDGM program to download
the extender.
In the PBXXX flash memory, an area is available where some miscellaneous
data can be saved. One item (LW-source) will indicate from where the
PBXXX will get the loadware and database : from OpenScape 4000 AMO or
CDGM. If this flash area is not initialized, OpenScape 4000 will be assumed
as default source. (Therefore the board will default to load from the
OpenScape 4000 unless it has been configured as a partial integration
board, in which case it can only be loaded via the CDGM tool)
- LW-source = OpenScape 4000
PBXXX will first activate the backplane communication and waits for a message from OpenScape 4000. Software and database are loaded from OpenScape 4000. On receipt of the configuration data, PBXXX will create all the necessary software components to handle calls. Configuration data will be saved in flash.
- LW-source =CDGM
download software and database via V.24 port (using CDGM tool).In this case the PBXXX will check whether it has a valid database or loadware stored in the flash RAM. If so, the PBXXX loads the database/loadware from flash which results in the creation of all the software components that are necessary to handle calls. If no database/loadware is available in flash, the PBXXX will wait for a database/loadware download from the CDGM tool. Configuration data received from the OpenScape 4000 will be ignored.
The EPROM extender program will first read this 'LW-source'
parameter from flash. Via the CDGM tool the PBXXX will allow to change
this parameter for a period of max 10 secs (this waiting period will
be skipped in case no terminal or modem is connected to the PBXXX board
in order to speed-up the start-up time). If nothing is entered, the indication
from Flash (or default) is used as LW-source. A LW-source update received
from CDGM will be saved in flash and used afterwards.