[PIC] Fast Serial Data
Martin McCormick email (remove spam text)
I recently have posted about building an audio delay
line using a PIC and the delay part plus a scheme to use a P.C.
to store several minutes of audio looks possible. Now for the
one awful problem. I need to receive the digital audio from the
CODEC I am using in order to be able to store it and send it
back out. It is a 2-wire interface in which there is a
64-kilobit/sec clock and a data stream that synchronizes to each
clock cycle. Should the USART on a 17C43 be able to clock in
those data and then deliver an interrupt every 8 bits received?
I hate to try to interrupt the PIC 64,000 times per second at
16.384 MHZ because that only leaves about 31 operations between
interrupts and I see nothing but trouble ahead.
If one could handle the data as bytes, that would make
everything lots easier.
In case anybody else is interested in particulars, the
CODEC is a MX-com.com MX639 which is relatively new. If the
USART can't be used in this way, I will probably use a 16C64
instead due to the number of I/O lines for other parts of the
project. So, it boils down to the best way to handle the 64,000
bit/S pounding that is going on all the time.
I also have, on hand, some 4-bit shift registers and
CD4017 decade counters that could be made to reset after the 8TH
bit if everything else fails. The CD4017 would trigger an
interrupt to tell the PIC to handle a new byte.
If you want to read about the CODEC, goto
To read about how it works,
None of this info will help in answering my question, but
I figured I would try to provide some useful information to
others while asking for some, myself. Thank you all.
See also: www.piclist.com/techref/microchip/ios.htm?key=serial
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