AVR-Chat

I designed a board for my railroad signaling project (outdoor, ride-on,
1/8th scale) around the ATMega32A and so far it has worked out well running
my multi-node CAN network based system.  

One of the regrets I have is that I did not take the advice of those that
recommended that I go with an ATxxx-CAN device rather than a non-CAN device
and an external CAN controller (I chose the MCP2515).  At the time I was not
sure that CAN would work for me so I wanted to keep my network options open.
CAN has been working great and I wish I was interfacing with an internal CAN
controller rather than having to deal with the extra SPI communications
layer … live and learn :-)

My other regret Is that I violated a rule I should have known - use the
device with the largest reasonable amount of memory available to reduce the
chances of "hitting the wall" in development.  Even though this was my first
real microcontroller-based design, I should have known better ... (see my
signature line!).

My board is designed around the ATMega32A and I am about at its memory
limits (with optimization turned on) and I have more features to add
(naturally).  I would like to upgrade to the largest compatible processor
that:
- 5v supply
- TQFN-44 package

Pins/peripherals I'm using (from memory without detail checking of the
code):
- 8 A/D inputs
- SPI
- TWI
- 1 UART (diag & monitoring)
- JTAG
- OC2
- INT2
- AREF
- 6 general I/O
- Timers 1&2
- 14.7456 Xtal
- Watchdog

I have checked the data sheets and it looks to me like I can choose from the
following:

ATMega644, 644P, 644PA, 644A
ATMega1284 & 1284P

Mouser does not seem to stock the ATMega1284x in TQFN-44 but DigiKey stocks
the ATMEGA1284P-AU-ND which would seem to fit the bill.

For my use is the ATMEGA1284P-AU-ND pin and software (with appropriate
changes in defines, etc.) compatible the ATMEGA32A-AU or am I missing
something?

Thanks in advance for any help you can provide ...
 
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