Echelon FT 3150 Smart Transceiver - Manual (Page 36)

Chapter 2 - Hardware Resources
30 FT 3120 / FT 3150 Smart Transceiver Data Book
When an EEPROM recovery occurs due to a checksum failure or other error, the event will be logged in the error
table of the FT Smart Transceiver. A test command will show EEPROM recovery occurred as the last error logged.
Reset Processing
During reset processing, the configuration checksum is checked first. If bad, and no configuration recovery options
are set, then a configuration checksum error is logged, the checksum repaired, and the device state is changed to
unconfigured. If the configuration recovery option is set, the configuration is recovered.
Next, the application checksum is checked. If bad, and the checksum error is in the system image, then a system
image checksum error is logged and the device state is changed to applicationless.
If the application checksum is bad, and no application recovery options are set, an application checksum error is
logged and the device state is changed to applicationless.
If the application checksum is bad and an application recovery option is set and the boot application does not contain
references to any off-chip ROM, flash, EEPROM, NVRAM, or RAM code, or there are no checksum errors in any of
these regions, then the application is recovered. Otherwise, an application checksum error is logged and the device
goes applicationless.
Signatures
All off-chip code areas have a 2-byte cyclic redundancy check (CRC) called the signature, immediately following the
area checksum. Signatures are stored in the area and in the memory map. Mismatches between the area signature and
memory map copy of the signature result in the device going applicationless. This mechanism prevents a partial
application load over the network which is incompatible with any unloaded code (such as code in ROM).