Hey Jan, thanks for making MyHDL :D

You do if you'd like to directly convert your model, which works so well at the high level, into C or RTL. Yes you can rewrite your Octave script in Verilog, but part of what makes MyHDL exciting is that this extra work is done for you.

I use Verilog as Verilog, and Python as SystemVerilog.

Type checking is done at simulation time, and ultimately during synthesis. Duck typing is immensely useful for higher level abstractions.

Chris KD2BMH

I agree that the essence of RTL isn't too difficult; the complexity arises when you use RTL to do filtering and modulation. Even the vendor tools are lacking when it comes to analyzing Digital Signal Processing. You have to use Simulink, and that's not a cheap proposition.

Chris KD2BMH

I would say that the main advantage of using Python is in the verification process - writing test fixtures and analyzing the results of simulations is much easier to do with the Python toolkit. Design of real world Digital Signal Processing for the FPGA feels much more natural.

In the end, All simulations end up running in a real Verilog simulator, after conversion. I use Icarus Verilog and it integrates seamlessly at this point. You can tie in your own Verilog modules too.

Chris KD2BMH

Thanks no_such_user... see you at Dayton! I'll hopefully be helping out at the TAPR booth.

73,
Testa KD2BMH

Chris Testa KD2BMH here...

This is one of the most interesting and challenging questions to answer. Here's a blurb excerpt from Eric Blossom, an early innovator in software radio as to why this stuff is so valuable:

"Software radio is a revolution in radio design due to its ability to create radios that change on the fly, creating new choices for users Perhaps most exciting of all is the potential to build decentralized communication systems. A centralized system limits the rate of innovation. We could take some lessons from the Internet and push the smarts out to the edges. These user-owned devices would generate the network. They’d create a mesh among themselves, negotiate for backhaul and be free to evolve new solutions, features and applications." - Eric Blossom, Exploring GNU Radio

What's exciting is now a radio, which has the "brains" to be a major part of Internet infrastructure (think Veriozon's cell towers everywhere) will fit in your pocket. This should enable a change in the landscape of the Internet itself, and I hope it frees our comms from bondage to wire's and large multi-national corporations.

This was my original inspiration, at least.

Here's the paper published in the TAPR DCC conference proceedings: http://www.tapr.org/pdf/DCC2012-Handheld-Software-Radio_KD2BMH.pdf

Also, follow me on twitter http://twitter.com/testa or my blog http://blog.testa.co/

Chris Testa KD2BMH here. marid, your suspicion is correct, the CMX991 transceiver I'm using has a low-end cutoff of 100MHz.

The HF converter w/ a NE-602 mixer in the latest QST looks like an attractive solution to support the missing lower frequencies receive, I'm guessing 2 would allow me to build a full duplex transceiver.

I'm using a 40MHz ADC & DAC, so at least some of the HF bands should be possible using direct conversion.

Either way, HF wasn't part of my initial plan, I'm focusing on exactly what I can fit inside easily, and then more features can be added later. Launch & iterate... the kitchen sink will come in one of those iterations :)

Hats off to the coder who blamed on that one. You've made history!