Re: [myhdl-list] TypeError: Unexpected type with toVerilog

[Christopher F. <chr...@gm...>]

On 5/25/2012 4:22 PM, Christopher Felton wrote:
> On 5/25/2012 3:58 PM, Jan Decaluwe wrote:
>> On 05/25/2012 02:54 PM, Christopher Felton wrote:
> <snip>
>
>>
>> How can key be defined, if the enum is defined inside the module?
>
> Good question, in the original example the enum was being used as
> "constant" values.  And "key" was of type intbv.  The quick answer might
> have been don't mix types?
>
> The odd thing I ran into is that it worked in the /always/ generator and
> not the /always_comb/.  Below is the complete example, you should be
> able to run it.
>
>>
>> Can you or Jan C provide me with a short but complete example
>> (including signal defs and conversion call) that fails?
>> I'll start thinking after that :-)
>>
>

This example for the most part is probably *bunk*.  I thought I had 
extracted a portion of a larger example, which I might have.  But the 
strange thing here isn't that the /always_comb/ didn't convert it is 
that the /always/ *did* convert.  I got the cause and effect backwards.

I would (should) have noticed this if I had created a test.

def test():
     clk = Signal(False)
     key = Signal(intbv(1, min=1, max=9))
     led = Signal(intbv(0)[8:])
     dip = Signal(intbv(0)[8:])

     @always(delay(2))
     def tb_clkgen():
         clk.next = not clk

     @instance
     def tb_stimulus():
         for ii in range(1,key.max):
             yield clk.posedge
             print("key %d led %d" % (key, led))
             key.next = ii
         raise StopSimulation

     Simulation((tb_clkgen, tb_stimulus)).run()

-------------
Output
-------------
key 1 led 0
key 1 led 0
key 2 led 0
key 3 led 0
key 4 led 0
key 5 led 0
key 6 led 0
key 7 led 0

-------------

Again, the odd behavior is with the /always/ generator conversion.  I 
believe, it created valid logic.  The converted code should simulate 
correctly while the MyHDL code doesn't.

This is *not* the error that I reported earlier, that the enum cannot be 
used in an /always_comb/.

Regards,
Chris