I use SiLabs almost exclusively. I do all development work with SiLabs parts because of the on-chip debug and on-board programming capabilities. I said "almost exclusively" because once in a while there is a need to leverage the SiLabs capabilities, such as I showed at that link, whilst targeting another alternative MCU for the actual target. Most often these cases are ones where legacy upgrades are being done or really low cost silicon must be targeted. My substitute of choice for these latter cases is the C8051F226 because it is the one SiLabs part that is most similar to the old reference standard 8052s in DIP-40 or PLCC-44 packages.

In fact I just completed a one-off hobby project where I used my C8051F226 Dev Kit board to develop code for a RF wireless display gadget that actually targeted an Atmel AT89C4051 part in a 20-pin DIP package. That part was chosen due to ease of building a neat prototype style construction of the display. I simply added a small 2x7 header on the display board near the 'C4051 socket that captured all the I/O used on the board and cabled it over to the 'F226 board for code development. After the code was complete I simply flipped a build time switch in the assembler code which eliminated the SiLabs specific code and enabled the Atmel specific code. I have to use a standalone programmer for the 'C4051 but that is a small issue to deal with compared with the ease of building with the DIP-20 package. Do note that if I had actually spun a PC board it would have almost assuredly included the F226 chip directly. It is possible to use the 'F226, which is of course a 3.3V part, to drive 5V I/Os due to the tolerant I/Os of the SiLabs technology.

Tom, note that if low pricing is not the most critical factor for your application then you may very well want to consider just using the SiLabs parts for your design. Do not let the 1-off pricing at Digikey scare you away from using these parts for a production quantity design. Digikey shows the 1 each C8051F023 part at 13.87USD and yet at the SiLabs web site they show 1K pricing at 11.13USD. (Note that I believe SiLabs uses www.mouser.com to fulfill orders from their web ordering pages because the prices and quantities available match the Mouser web site).

Michael Karas