Re: [avr-gcc-list] FREEICE project

[David Brown]

Hi,

I have a couple of thoughts about the interfaces for the freeice.  Many
low-cost tools for jtag/bdm use a parallel port, and let the host pc do the
timing (such as P&E's bdm interfaces).  Most debuggers and programmers that
do their own timing use a serial interface (such as Atmel's avr jtagice),
and some modern ones us usb or ethernet for speed.  Are you providing direct
compatibility with existing parallel port devices, by letting the host
control the lines directly?  If not, then are there any real benifits of
using the parallel port?

As far as I understand it (I'm not too hot on the internals of gdb, although
I once fixed a bug in m68k-bdm-elf-gdb on windows), gdb can be patched to
support new connection methods (as is the case for m68k-bdm-elf-gdb), or it
can communicate using the standard gdb protocol over a tcp/ip socket or a
serial port.  For example, avr-gdb uses a tcp/ip socket to communicate with
helper program that talks to the hardware, as does msp430-gdb (in that case,
the helper program must be closed-source, because of TI's NDA).  So would it
not make more sense for the interfaces on the freeice to be a serial port
and an ethernet port (you mentioned the ethernut board - that should give
you a head start on the hardware and software)?  Then standard gdb could
talk directly with the unit.

Any chance of support for the msp430 (jtag) and the MPC56x (bdm) ?  Then one
freeice would cover everything for me...

David


> Hi all,
>
> At this moment I know that there is some fuzz about the freeice
> project but I can explain more :
> the freeice project should implement at least 2 synchronous
> protocols : jtag and bdm.
>
> The jtag is used - amongst others - by ARM7/9 and AVR. The
> freeice project will support these 2 types of microcontrollers.
> The bdm protocol is -like jtag - a synchronous protocol
> and is used -amongst others - by the Coldfire and 683xx series.
> The freeice project will support these microcontrollers too.
> I worked before with the ARM7, 683xx and Coldfires series
> but I wasnot happy with the solution the way that the parallel
> port had to be used.
> Take into account that these protocols are synchronous means
> that it is somewhat difficult to put in it a system based
> on events (I can send some details if you like).
> I wanted to use a more practical and modern use of communication
> so the freeice project with the gdb_serializer has been born.
> Therefor the gdb_serializer should have a more modular setup.
>
> And to be clear : the gdb_serializer (what is in a name ?) will
> be placed under GPL.
>
>
> Status :
>
> Hardware
>
> The hardware (pcb) is almost finished except for very small
> details (the pcb has been made in Eagle). I was contacted by Harald
> Kipp (sorry if I mispelled your name) who is willing to put it
> into production. He is the person behind ethernut amongst others.
>
> Harald gave me some hints to improve the design. If all is well,
> then we have to do some EMC tests which *is* required if you want to
> sell these boards in Europe.
> At least the schematic diagram and pcb layout has been put on the
> freeice project.
>
> I have choosen the hardware such that it shouldnot be a problem
> to get it. Currently I have an experimental board based on this
> design : I can put some pictures of my experimental board on the
> freeice site.
>
>
> Software
>
> I wrote some documents and flowcharts but they are still heavily
> under construction.
> The cooperation with GDB is also defined but this might also change.
>
> The communication host <-> gdb_serializer is AFAIK ready and is
> based on parallel port and usb :
> usb is working finally right now after having lots of problems.
> The parallel port should be expanded and tested. At this moment the
> parallel port has low priority.
> I made some preliminary host software to talk to this board but
> the software is only based on Linux (it uses libusb). The software
> isnot finished so expect some bugs, frankly I found 2 minor ones
> (but not critically) yesterday dough ...  Updates will follow.
>
>
> The beginning of this year we did lots of reversed engineering
> on the AVR jtag and at this moment we think that we have sufficient
> info to implement this protocol into the gdb_serializer.
> The lowlevel documentation of the jtag protocol is more or less
> ready and currently I am implementing this in in my experimental
> board. So the AVR will be the first one to be implemented.
>
> Feel free to ask if you are interested.
>
>
> Armand
>
>
> *******************************************
> * choose GNU/Linux : GNU/Linux is Freedom *
> *******************************************
>
> ----------------------------------
>
> Armand ten Doesschate
> Welschapsedijk 141
> 5652 XL Eindhoven
> the Netherlands
> tel : (++31) 40 2571 274
> e-mail : address@hidden
>
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