Ruth Hendrix

HCS12 In-Application Reprogramming

Discussion created by Ruth Hendrix Employee on Jan 26, 2006
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Posted: Sun Apr 17, 2005 1:31 am    

I want to develop an application for HCS12E128 and introduce the possibility of updating the software application through RS232, without any external hardware, the command for reprogramming will be with a RS232 command to initiate the process. Any idea how to organize the loader, application, interrupt vectors update,...?
Someone have experience in this?

Posted: Mon Apr 18, 2005 9:58 am    
There's a RAM bootloader for the S12 in AN2546 that uses the CAN and SCI ports. This loads what you need into RAM.
You may be able to take this as a starting point and modify it for your individual needs. In general you want to avoid having the flash programming algorithm stored in the part.

Other useful documents are: AN2720 and AN2548
Posted: Tue Apr 19, 2005 12:18 pm    
a thought - run a fixed boot loader out of an unpaged area and set a flag in e2 when its time to upgrade. reboot the device and in the boot loader check if its time to upgrade. start up SCI and bring down the new file. when ur done with the writing the code down to the device clear the flag in e2 and reboot again and jump to your new program.
Posted: Mon Apr 25, 2005 7:11 am  
There is an app. note. AN2720/D that might help you.