Hello all,
I'm trying to choose a microprocessor for a new design and would like to get input from members of the community who have used these processors. The requirements are an Ethernet MAC (PHY would be nice, but haven't found a chip which meets this plus the other requirements), I2C, external memory bus to access 4MB SRAM (or SDRAM) buffer, hobbyist-friendly packaging (not BGA, preferably QFP), and cheap, if not free (i.e. GNU), development tools, RTOSes, and TCP/IP stacks. A strong web-based user community would be an added bonus.
The MCF52233 would have been perfect if not for it's lack of an external memory bus. Similarly, we looked at the Atmel AT91SAM7X family, but had to eliminate it due to its lack of an external bus and I2C. I've pretty much narrowed it down to a choice between the Freescale MCF5270 and MCF5208, both of which have on-chip Ethernet MACs and SDRAM controllers. I've also worked with the Coldfire family before, but not ARM, so that is why we're leaning in that direction. The 5208 and 5270 are so similar, however, I'm having a hard time determining the which is better for our application. Looking at Digikey, it seems that the MCF5208 is not as readily-available in the QFP package as the 5270 is. Does anyone have any comments regarding supply issues for these parts. We're not going to be using large quantities of these, maybe a few hundred per year, so we'll probably have to get them from a major distributor like Digikey or Mouser.
If anyone has any other recommendations of microcontrollers I should look at, I'd be interested to hear it. An on-chip Ethernet MAC is not an absolute requirement, as long as drivers for external Ethernet controllers are available and the total system cost is minimized.
Thanks in advance, Alex Parkinson