Re: [ECOS] RE: Power PC Application

[Brendan Simon <bsimon at ctam dot com dot au>]

John Fisher wrote:

> I also have been trying to get gdb and insight working with BDM and the
> Macraigor Wiggler, however I am experiencing the following problem with gdb
> and/or wigglers.dll. I am using the Motorola MPC8xxFADS board.
>
> After issuing "target ocd wiggler lpt1"
> and "ocd reset" from gdb any attempt to write to the MPC860's SYPCR register
> fails. When the register is read back 0xFFFFFF07 is obtained, which is the
> boot up value. The reason I am trying to write the SYPCR register is to turn
> the watchdog off.
>
> My first thought was that gdb itself is writing this register and since the
> register may only be written once following reset, that was the explanation.
> However gdb writes the register during its target command - before the
> reset - and since it writes 0xFFFFFF88 it is obviously not succeeding
> either.
>
> I have no trouble writing the SYPCR register when using OCD commander, the
> debugger available from the Macraigor website.
>
> I am taking a slightly different approach from the gdb authors. Writing
> 0xffffff0f stops the watchdog timer from counting while FRZ is asserted -
> this is all that should be necessary. The gdb authors disable it entirely by
> writing 0xffffff88.
>
> It appears that gdb and the wiggler are either not resetting the board
> properly or are writing the default value of the SYPCR register just after
> reset.
>
> Does anyone know whether source is available for wigglers.dll? I have asked
> at macraigor but received no reply.

Good luck.  I have hassled them a few times about Linux drivers and have never
heard anything from them.  I offered to develop a free Linux driver for them so
that Linux users could buy Wigglers thus increasing their market potential.  I
didn't here a thing from them.