> My initial impression is : > > The PIC has excellent support and is popular but has a idiosyncratic > architecture? The PIC is popular, since it works well, is cheap, can be programmed with $5 worth of parts, and is practically indestructible (except if you goof while programming it; the programming circuitry is touchy and its code-protect fuse can easily convert expensive window parts into $20 tie pins. As for its architecture, its description is more unusual than the arch- itecture itself; the only "idiosyncracy" most programmers have to worry about is the irksome way the memory is paged (once you get used to Mchip's terminology). > The AVR is not so widely used but is generally faster (1 instruction per > clock at 16MHz) and is slightly more conventional in it's architecture > (although also Harvard). The AVR devices are faster, but their instruction set is not as well suited to I/O as is the PIC's. In particular, the PICs can access I/O devices like any other register, whereas the AVR requires special in/out instructions. Beyond that, the PIC vs AVR debate is mainly one of taste; the PIC allows easy access to all of its registers, but all operations have to go through a single accumulator; the AVR has 32 general-purpose registers (no dedicated accumulator) but access to anything outside those registers is more difficult than with a PIC. Six of one, 1/2doz of the other.