Motorola coldfire520X and gcc/gdb

Rolf Fiedler Rolf.Fiedler@Ferrari.DE
Mon Jun 9 23:41:00 GMT 1997


On Mon, 9 Jun 1997, Tony Armitstead wrote:

> 
> > > On Fri, 6 Jun 1997, Chris Johns wrote:
> > > 
> > The driver for CPU32 and CPU32+ boils down to send the BDM commands over
> > the BDM send/receive line. _If_ this is still a 10/8 pin connector with the
> > same timing, you can use the many available PD parallel port BDM
> > interfaces, and so probably the driver with only minor changes. But this
> > needs very careful checking re. timing, etc.  Especially the single
> > stepping is very critical. However, it seems workable.
> > 
> 
> Sorry chaps but the BDM interface on Coldfire is very different from 
> that on CPU32 - it also uses a 26 pin connector and not the CPU32 
> 8 or 10 pins. However it is a much better BDM interface than CPU32 in 
> that it allows dynamic access to memory, on-chip breakpoints (better 
> than 68360) and nearly non-intrusive tracing of program execution.

right, except that we don't need to be sorry

> On the down side you cant do a simple BDM parallel cable interface 
> since the BDM serial transfer has to be synchronised to the CPU which 
> is just not possible without some extra hardware in the cable header.

wrong, it can be done quite easily with less hardware than the
PD-BDM interface for CPU32
You only need to synchronize the DSI, DSO, DSCLK, BKPT signals with
the CPU_CLK which is kindly provided on the 26 pin BDM connector.
So you can build a parallel port adapter just using one octal register
or a GAL like P&E Microsystems do.
This solution, however, does not allow tracing - it's just for BDM
debugging. For tracing one would need an aditional logic analyzer
due to the trace speed and the relative slowness of a PC.

> I should point out that Noral who I work for makes BDM interfaces for 
> both CPU32 and Coldfire ... but I will say no more.

and many others do

> ---------------------------------------------------
> Tony Armitstead                   tonya@noral.co.uk
> Noral Micrologics Ltd.         http://www.noral.com
> Logic House, Gate St.           ftp://ftp.noral.com
> Blackburn, Lancs.                 Tel: 01254 682092
> England, UK.                      Fax: 01254 680847
> ---------------------------------------------------
Kind regards, 
Rolf

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|  ||||||   |  Rolf Fiedler                                            |
|  6 6  \   |  Electronic Design Engineer                              |
|  /_  ) |  |  Ferrari electronic GmbH                                 |
|   >   /   |  phone: +49 3328 4559 0  E-Mail: Rolf.Fiedler@Ferrari.DE |
|   |  |    |  fax  : +49 3328 4559 60                                 |
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