Wavefront chip wordclock generation?

[DavidS]

Quick question - For the WavefrontSemi chips like the 1K dsp and the converters, how hard is it to generate the wordclock signal? is it any different from a clock pulse from a crystal? I looked through the Wavefront datasheets, but they weren't illuminating.

[Peter Snowberg]

The word clock runs at the sample rate which for most applications will be 48KHz.

If you start with a 12.288MHz master clock and then divide that by 256, you get a nice 48,000Hz signal.

Checkout the schematic of the evaluation board for a cookie-cutter solution.

The AL3201B makes it's own work clock for the rest of the chips to use.

[DavidS]

Huh, that DOES add a little overhead, but I guess the board (for the project I'm thinking of, the loop router/mixer/dsp etc.) will already have a good number of chips on board.

Thanks!

[Peter Snowberg]

It does take a little, but you could just as easily use a single chip like a 4040 instead of the two 74xx161s.

If your microcontroller contains hardware PWM generators, you can program a 50% duty cycle with a frequency of 48KHz and now you just need to connect another wire, with no additional chips. If you use the on-board oscillator circuit of the uC and one PWM output, you can eliminate the three chips that Alesis Semi (now Wavefront Semi) used to make the clock here: http://www.wavefrontsemi.com/developementboard/WavefrontEV3101A.pdf

[DavidS]

Well, that's simple enough! Thanks for the info!