You have some specific requirements (eg, the onboard CAN) - so that should significantly narrow-down the options.

In your position, the key objective is to have something that works in 6 weeks time, rather than to optimise the best possible price for volume production - so probably best to just go for the option with the biggest RAM & Flash that supports all your other requirements!

I would also strongly recommend that you get something with on-chip debug.


It's more likely to be Code size than RAM size where 'C' could make a difference.

The 2 keys to writing efficient 'C' are:

1. A thorough understanding of the underlying architecture;

2. A thorough understanding of the tools (compiler, etc) that you're using.

In particular, you should spend time familiarising yourself with the specific language extensions offered by your compiler; ie, a lot of studying of the Manual!

Here are some general guidelines: http://user.it.uu.se/~jakob/pu...f-2001.pdf

And here is specific advice for Keil: http://www.keil.com/support/man/docs/c51/c51_xc.ht