Re: [avr-gcc-list] gdb and the stk500

[Theodore A. Roth]

On Sat, 5 Oct 2002, Shaun Jackman wrote:

:) On the stk500 there's a at90s8535 that controls the target
:) chip. I'm not totally familiar with the board yet, but I thought it
:) might be controlling the target chip through jtag. In which case, the
:) serial connection to the master could be used to debug the target
:) chip. Does the stk500 have a debug protocol built into it?

The stk500 knows nothing about the jtag at all. I would think that the
8535 talks to the target device via either the SPI interface (when ISP6PIN
is connected to one of the SPROG headers) or the high-voltage parallel
programming interface (the "PROG DATA" and "PROG CTRL" headers). There's
probably some extra circuitry involved in the hi-volt-par situation
though.

:)
:) My question boils down to this. With just a stk500 connected to my
:) serial port, is there any way to make "(gdb) target remote
:) /dev/ttyS0" work?

No. Two totally unrelated communication protocols are at work here.

Now that the jtagice protocol is out, I'd like to add a jtagice target for
the avr port of gdb so you could to this:

  (gdb) target jtagice /dev/ttyS0

Currently, you have to use the avarice program as a middleman between gdb
and the jtagice box which is turning out to be a bit cumbersum for me
(due entirely to me being lazy ;-).

Ted Roth

:) On Sat October 5, 2002 15h52, Theodore A. Roth wrote:
:) > I'm not exactly sure what you mean here.
:) >
:) > I use this setup daily:
:) >
:) > mega128 <-> stk501 <-> stk500
:) >                \
:) >                 --> jtagice <-> avarice <-> avr-gdb
:) >
:) > The jtagice box physically connects to the stk501's jtag port,
:) > avarice talks to the jtagice via serial cable.
:) >
:) > There is no facility in gdb for it to talk directly to the stk500.
:) >
:) > Hope that helps.
:) >
:) > Ted Roth

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