[myhdl-list] Unsupported list comprehension form

[Jock T. <tan...@gm...>]

Hello!

I’m a Python web developer and a bit of radio hobbyist, and as such I’ve
been playing with MyHDL for a couple of weeks. I’d like to apologize in
advance if I have got some basics completely wrong from the start, because
that’s pretty possible. But I’d like to get a bit of a clarification, or
even better, an advice, concerning an error I recently stuck with.

I’m trying to implement a carry-lookahead adder from
http://www.ece.lsu.edu/ee3755/2013f/cla.pdf, and that’s how I wrote a carry
generator part (from page 5):

https://bitbucket.org/jock-tanner/asceticore/src/e0dce2f822639b66a024fe2f53ef2bcc98e8d2f2/components/adder.py?at=master&fileviewer=file-view-default#adder.py-64:92

The code simulates fine, but when I try to convert it to Verilog, the error
comes up:

“myhdl.ConversionError: in file
/home/tanner/workspace/pr043-asceticore/project/asceticore/components/adder.py,
line 89:

Unsupported list comprehension form: should be [intbv()[n:] for i in
range(m)]”

Since I wish to put this design into an FPGA (I haven’t got the board yet,
but definitely will), I consider the conversion part important. But right
now I’m clueless of what I have done wrong conversion-wise. I’ve read the
manual (http://docs.myhdl.org/en/stable/manual/conversion.html), but it
didn’t get me any further.

Any ideas about how I should rework my code? Sorry again for bothering you
with such small and (hopefully) trivial matters.

JT