Re: [avr-gcc-list] avarice speed

[David Gay]

Theodore A. Roth wrote:
> On Fri, 13 Jun 2003, Ralph Mason wrote:
>
> :) Has anyone done any modifications to avarice to allow it to run at 115200
> :) and to increase the JTAG communications speed.
> :)
> :) It seems to be about 10 times slower than using the ICE in AVR studio.
>
> Which version of avarice are you using? The latest cvs version should
> be running at 115200.
>
> I'm not sure about the JTAG clock speed though. It's not clear in the
> avr060 app note how to set it. Here's the code that sets it in
> avarice:
>
>         // Set JTAG bitrate to 200kHz.
>         // ff: 1MHz, fe: 500kHz, fd: 250khz, fb: 125Khz
>         setJtagParameter(JTAG_P_CLOCK, 0xfd);
>
> I just changed that to 0xff and things seem to be noticeably faster.
>
> Could you verify that for me? If it works well for you too, I will
> commit it.

There's some mutterings in some docs somewhere about not exceeding 1/4 
of the chip frequency. So if the JTAG is set to 1Mhz, you need to be 
running the processor at 4MHz+. The best solution might be to add some 
kind of JTAG-frequency startup option.

David Gay
address@hidden