I have recently got my hands on an old board that uses an HCS12 processor that has a BDM interface. Unfortunately, I do not have any of the boards that are supported by the excellent USBDM tool ( https://github.com/podonoghue/usbdm), but I do have plenty of other development boards lying around that I could implement into a bare-bones BDM tool.
Is there any documentation about how the BDM Protocol actually works? Something with logic diagrams and a list of the byte for different commands that BDM supports?