Hello All... I have an interesting one for you guys....
The processor is a HC09GZ48
We have a sensor here that Txs and Rxs MS CAN (50K) Messages along with other minor processes, no FLASH reading / writing, just some ADC readings and CAN.
There exists a boot loader that allows us to reprogram the device over CAN.
The Boot loader resides at $D600, and the program resides at $4000
At some point in the developement cycle, the Sensor, while running the application, would lock up on the Rx'd of a CAN Msg. It would Tx CAN messages without issue. It would correctly accept the application during the programming over the CAN and the same Application code would work on older sensors.
I successfully isolated two S19 memory uploads of the same hardware, one with the code working correctly, one with the code locking up on the Rx of a CAN message while the application was running
using KDIFF I could see only one difference in the S19 file... Changes to memory location $FF80, which looks like the Flash Protection Register...
The Bad S19 File has $FF80FFFF
The OK S19 File has $FF80ABFF
How this affects CAN Rx'in I have no idea... please remember that the rest of the S19 file is completely identical.