michael coury

RX of a CAN MSG Locks up GZ48 MCU only when $FF80 Register is different!?!?

Discussion created by michael coury on Feb 15, 2008
Latest reply on Feb 18, 2008 by michael coury
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.

Thanks for any help in this matter

Please see the attached image

Message Edited by mjcoury on 2008-02-15 02:25 AM
Message Edited by t.dowe on 2009-10-19 10:44 AM