[U-Boot-Users] BDI2000 and MPC8260

Jerry Van Baren gerald.vanbaren at smiths-aerospace.com
Tue Sep 6 21:48:57 CEST 2005

Wolfgang Denk wrote:
> In message <431DB954.9030803 at smiths-aerospace.com> you wrote:
>>* Freescale seems to have stopped providing unfettered access to the 
>>BSDL (Boundary Scan Description Language) interface to their processors. 
>>  For instance, the MPC8260 is not in the list:
> We were never able to pass their NDA roadblocks when we asked for the
> necessary information to extend the BDM4GDB adapter for 82xx... :-(

Slightly different question, different answer ;-).  The BSDL is 
describing the processor I/O ring shift register, allowing the JTAG to 
wiggle pins.  What you are referring to is the COP (?) debugger 
interface which is also accessed via JTAG but is proprietary.  The BSDL 
_is_ available as Rune pointed out.  This allows you to program memory 
(very slowly) by shifting an {address, data, chip select}, toggle the 
write line, repeat ad nausium.

Note that you have to be careful with wiggling pins via JTAG: if you 
inadvertantly set two pins that are connected together to be "output" 
and set them to fighting, one of them will lose (generally the 
processor).  I would never do that, but know someone who did ;-).


> Best regards,
> Wolfgang Denk


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