John Payson wrote:

> Both approaches have a further limitation in that there isn't any
> "good" time to change the output value without causing some
> disturbance (e.g. if the output value goes from 7 to 8, there
> may be an interval in which 15 consecutive zeroes or ones are
> output.

  Ah!  Now there's an advantage of the "Stamp" method (AKA DDS or Direct
Digital Synthesis).  Instantaneous change in the "width" value will be
smoothly incorporated into the bitstream.

  Particularly useful if used not for PWM but for frequency modulating a
sinewave.
--
  Cheers,
        Paul B.