AVR-Chat

The clone JTAG debuggers only support very old chips. For more modern chips
you need either an AVR Dragon, an AVR JTAG ICE MK II or an AVR One.

On Thu, Jan 20, 2011 at 9:20 PM, Chuck Hackett <egroupscdh@up844.us> wrote:

> Well it's an old story and I should have known better but I am running out
> of memory
> on my controller and I need to upsize and I only have a couple of weeks to
> get this
> done.
>
> I'm looking at switching from an ATMega32a in a TQFP-44 to a ATMega644 in a
> TQFP-44.
>
> Due to the fact that the boards are already made, I need to stick with the
> TQFP-44
> package and ATMega32 pin assignments.
>
> I have compared the pin assignments and the "Features List" at the top of
> the
> respective data sheets and it appears that the ATMega644 will work for me.
>
> I have also looked at Atmel's Application Note: "AVR505: Migration between
> ATmega16/32 and ATmega164P/324P/644P", which states, in part:
>
> "The ATmega164P and the ATmega324P are new and enhanced versions of the
> ATmega16 and
> the ATmega32 respectively, and ATmega644P is a new 64kB device with the
> same
> features. An important improvement is the possibility for low voltage
> operation
> (1.8V) with ATmega164P/324P/644P and decreased power consumption.
> ATmega164P/324P/644P also features an extra USART and can run at
> frequencies up to
> 20 MHz."
>
> "This application note summarizes the differences between ATmega16/32 and
> ATmega164P/324P/644P and is a guide to assist current ATmega16/32 users in
> converting existing designs to the ATmega164P/324P/644P."
>
> I see nothing in the App. Note that would indicate that the ATMega644 would
> not work
> in this application.  The "low voltage operation", second USART, etc. are
> nice to
> have but are not of concern at the moment.
>
> As far as I can tell AVR Studio and WinAVR both support the ATMega644.
>
> I use the processor defines supplied with WinAVR so, according to the App.
> Note I
> might have to change some register names in my code, but, otherwise I
> should be ok.
>
> One thing that concerns me is that it appears that AVR Studio does not
> support JTAG
> debugging of the ATMega644 via JTAG ICE Mk-1 which (as far as I know) is
> what my
> ECROS AVR "ICE Cube" emulates (Graham: Can you speak to this?).
>
> This means that I will have to upgrade to a new JTAG adapter.  Since the
> ICE-Cube
> has served my needs well I have not kept up on developments in this area,
> which
> leads to the question:
>
> What options should I look at?  Are there any "deals" out there?  It seems
> to me I
> saw mention on the list of a low cost Dragon, is that still available,
> would this be
> satisfactory?  Pros/Cons?
>
> I currently do all my work with AVRs but, who knows, I may check out ARMs
> in the
> future.  Does that effect my JTAG choice?
>
> Cheers,
>
> Chuck Hackett
> "Good judgment comes from experience, experience comes from bad judgment"
> 7.5" gauge Union Pacific Northern (4-8-4) 844
> http://www.whitetrout.net/Chuck
>
>
>
>
> ------------------------------------
>
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>
>
>
>


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