topic Flashing MC9S08QG4 over BKGD in 8-bit Microcontrollers

Flashing MC9S08QG4 over BKGD

follopo — Fri, 11 May 2012 21:56:46 GMT

I've been looking pretty hard for a solution to this and I might be missing something so I just decided to ask. Here's the deal:

I've written code for a MC9S08QG4 and have it compiled and ready to load onto the MCU. The file needs to be loaded into the FLASH through the BKGD pin from a DaVinci SoC. Basically, I have no idea how to push the file from the DaVinci to the MCU. As far as I know, there is a routine to do this already and I just need to modify it for my application but I haven't been able to find it. I have the MCU's datasheet and know that data is sent over BKGD MSB at 16 BDC clock cycles per bit. What I need help figuring out is how to access, erase, and program FLASH through the BKGD pin. Any help or referral to help would be appreciated. Thanks.

Re: Flashing MC9S08QG4 over BKGD

kef — Mon, 14 May 2012 20:00:03 GMT

BDM protocol is documented in 17.2 Background Debug Controller (BDC) in QG datasheet.

How to erase and program FLASH you may find in 4.5 FLASH.

Routines for BDM communications probably can be found in USBDM and OSBDM source codes. Don't know how would be easy to port them to DaVinci, since BDM protocol is time critical.

Re: Flashing MC9S08QG4 over BKGD

follopo — Mon, 14 May 2012 20:05:18 GMT

Thanks for the references. I'll check out that source code you mentioned and figure out how to adapt it. It sounds like what I was looking for.