I got an ADA2200. The 28-th boot's byte should be a checksum of the previous 27 bytes.
What is the particular checksum algorithm that this unit uses ?
The checksum is calculated simply by adding up the values that are read back over the EEPROM and then taking the 8 LSBs. On the ADA2200, a total of 27 bytes get loaded from the EEPROM and the 28th byte contains the checksum. The state machine inside the chip reads back the first 27 bytes, keeping a running total of the values read back. It then reads back the 28th byte which is the checksum. If that matches the 8 LSBs of the running total, then the state machine concludes that the read backs were successful.
Retrieving data ...