I've gotten some information in email about BDM so I can not claim credit for this analysis/research :-)
The PowerOPC BDM is not the same as the Coldfire BDM. Some signals have the same name, but that is where the similarities end. The PowerPC relies of instructions serialized into the core (DPIR register) and data moved in and out of the core (DRDR register), while the Coldfire has specific operations (e.g. read memory location.) The number of bits serialized into the device is also different, 32 or 7 for the PowerPC (depending on the command), 17 for the Coldfire (16 data and 1 status). A useful feature of the Coldfire is that certain operations can be executed while the core is running (they do cycle stealing for operations such as read/write to memory locations) while you have to stop the core to do this with the PowerPC (do not quote me on this last part, but when I wrote the PowerPC library for the Jumpercable I think I remember I had to stop the core for everything.) Also, some signals are quite different. The BDM has both HRESET and SRESET, while the Coldfire has a BKPT that instantly stops the core when asserted and can place the core in debug immediately after reset. Right next to me I have a Netburner SB70 board, and I am waiting to find the time to work on a Jumpercable library for the the BDM interface, but it is a lower priority for now. The market for Coldfires is not that big (nothing that Freescale touches is big anymore...:( and it is mostly owned by 3rd party tools. -- Øyvind Harboe Embedded software and hardware consulting services http://consulting.zylin.com _______________________________________________ Openocd-development mailing list [email protected] https://lists.berlios.de/mailman/listinfo/openocd-development
