Embedded clocks

I was posting to the thread on the embedded clock in a Manchester
encoded bit stream and realized that the clock is not truely embedded
in the data stream. I say this because you still have to know the
clock rate in order for it to work. The decoder has to lock out the
edge detection for the time between bits to prevent detecting false
bits. You have to know the data rate in order to time this lock out
period. Of course the timing is much less critical than a typical
clock, even an RC clock. But none the less you have to have a clock of
a given frequency.

Are there any methods of transmitting data and clock on a single wire
that do not rely on the decoder having knowlege of the clock rate.
This is not entirely academic. I have an interface I am working on
where I need to multiplex multiple signals over a single pin. One is a
serial bus and the others are discrete pins which require very accurate
timing. Idealy the decoder would not have a clock, but rather the data
would be self clocking. I would like to use a very low power CPLD that
could be powered by either the signal or at least only require a few mA
of current from an LDO on the battery connection.

Is self clocking on a single pin possible? I am thinking that the
extra info has to be presented in some manner that requires either a
timing or amplitude measurement.

.

Relevant Pages

  • Re: Confused about Kernel Streaming / DShow clocks...
    ... If you are a stream class minidriver, you implement the clock using the ... > written under the stream class driver. ...
    (microsoft.public.development.device.drivers)
  • Re: Confused about Kernel Streaming / DShow clocks...
    ... If you are a stream class minidriver, you implement the clock using the ... > written under the stream class driver. ...
    (microsoft.public.win32.programmer.directx.video)
  • Confused about Kernel Streaming / DShow clocks...
    ... queried to give me a very accurate clock source. ... master clock for the graph (which might be themselves, ... then my clock support is going via the stream class driver. ...
    (microsoft.public.development.device.drivers)
  • Confused about Kernel Streaming / DShow clocks...
    ... queried to give me a very accurate clock source. ... master clock for the graph (which might be themselves, ... then my clock support is going via the stream class driver. ...
    (microsoft.public.win32.programmer.directx.video)
  • Re: MPEG2 TS source filter
    ... > The documentation states " With transport streams, the demux synchronizes ... > its clock to the PCR stream that corresponds to the audio or video stream ... The reference clock tells you what time it is now. ... Most graphs measure time using the audio DAC clock; ...
    (microsoft.public.win32.programmer.directx.video)