[En-Nut-Discussion] Ethernut 5.0 Schematic Preview

[duane ellis]

Harald > [nut5 schematic for review]

duane> 5)   Why is JTAG a non-standard connector? (not 20pin?)

Harald> All Ethernuts do have the same JTAG connector. For historical 
reasons
Harald> they use the AVR layout, which doesn't provide RTCK, but a spare 
pin.
Harald> This one can be used for RTCK by connecting pins 3 and 4 of JP2.

Yes, but ARM is ARM, and AVR is AVR..

Duane>  The RTCK issues is critical if you want to debug low power 
shutdowns.

Harald>I agree on this one. However, as far as I can say, it is not 
supported
Harald> on the OpenOCD/FTDI combination. Anyway, RTCK may be available 
at pin 8.

yea, many do not support RTCK :-(

I use this:   http://www.segger.com/at91.html

Why? For $129 USD (digikey) - it comes with a license for *ALL* features
- ie: GDB support is $FREE$ -
- ie: RDI (arm tool chain) is $FREE$
- Etc...

Atmel's free flash programing tool for ARM chips "SAM-BA" - works with it
The key here is this - as an OEM/(atmel) version of seggers jtag probe 
device,
it only works with ATMEL parts and comes with all features enabled.

Exception: the 'segger flash tool' is not $extra$ - but who cares - 
Atmel supplies
a very nice tool called SAMBA for free.

The non-OEM version of segger jtag - those features cost extra.

I believe you should change your mind about this.

Duane> [jumper pin holes]

Harald> May be in the final layout there is some space left for a 
minimal area.

An alternative would be to have test points, or solder eye-lets one can 
solder wires to...
Soldering to chip pins sucks....

-Duane.