DSP and the Microcontroller book report

 

I was thinking about the all-pass filter concept (used in the W3AM symmetric audio filter for speech) and recalled that the all-pass filter had been discussed in the Motorola book: Digital Signal Processing and the Microcontroller.  I did an internet search and found this Bitsavers scan on Archive:

https://archive.org/details/bitsavers_motorola68SignalProcessingandtheMicrocontroller_11141119/page/n11/mode/2up

I first read this book when I got a Motorola 68HC16 course and development board, previously mentioned here:

https://wb9kzy.blogspot.com/2022/06/why-pic.html

BTW, the bookmark shown above in my copy was this printed message:

Motorola used to do some stuff nicely like introducing new microcontrollers with dev boards where they'd send a refund if you passed a test or completed a task (of course Motorola also did other stuff not quite as good like continuing support and transition to Flash memory ;).  Although I never really used that 68HC16 chip again (way too many SMT pins for kits!)  I do revisit this book periodically.  It is a simplified intro to DSP which makes the concept of sampling the input and then using math on the samples to perform various filtering tasks.  The actual 68HC16 course did have detailed stuff on selecting the weighting coefficients and taps but this book was a good prep for getting into that.

As I recall the 68HC16 project output looked kinda funky to me on my Tek 475 scope - I think I had some sign problems in the code :)

Best Regards,
Chuck, WB9KZY
http://wb9kzy.com/ham.htm