new hardware in progress: labsw

Werner Almesberger werner at almesberger.net
Fri Sep 2 05:04:59 EDT 2011


Ron K. Jeffries wrote:
> On a more serious note, curious about choice of  SiLabs C8051F3xx.
> Was it a) better or b) cheaper or c) you just love writing 8051 assembler.
> ;)

I've used the SiLabs chips before - the F326, a smaller brother
of the F320, for the first version of atusb, and the F320 for
"cntr" (1).

SDCC can generate 8051 code, so development isn't as evil as it
may seem at a first glance. What's nice about the SiLabs chips is
that - unlike the Atmels (2) - they can do USB without a crystal
or resonator. The SiLabs chips also have 5 V tolerant I/Os, which
will be very handy in this project.

Last but not least, this gives me an excuse to merge the USB
stack I made for these chips into the more advanced version I
made for the Atmel chips.

(1) http://projects.qi-hardware.com/index.php/p/ben-wpan/source/tree/master/cntr/

    This is a ben-wpan sub-project that produced an
    arbitrary-precision frequency counter, for measuring the
    accuracy of the Ben/atben/atusb crystals.

    Its functionality has since been absorbed into the atrf-xtal
    utility:

    http://projects.qi-hardware.com/index.php/p/ben-wpan/source/tree/master/tools/atrf-xtal/atusb.c

    atrf-xtal also does much better math than the original
    software for "cntr":

    http://lists.en.qi-hardware.com/pipermail/discussion/2011-June/008094.html

(2) Not counting V-USB, which can do low-speed without crystal on
    some chips, but the choice is quite limited.

- Werner




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