Re: new AMS LRM 2.2 draft c - parameter descriptions

Geoffrey.Coram wrote:

>edaorg@v-ms.com wrote:
>
>
>>I agree that if you have 400 different descriptions you'll want to minimize
>>your typing, the template approach does that - assuming a bunch of them will
>>be using "ohms" it would be something like -
>>
>> parameter Ohms#("Resistance") from [0:inf);
>>
>>which is less typing than -
>>
>> parameter real "Ohms" from [0:inf) --- "Resistance";
>>
>>
>
>While several parameters might have the same units (RD, RS are ohms),
>none of them will have the same description; it would be very little
>help to the user if the "drain resistance" and "source resistance"
>were given the exact same description.
>
You would have something like:

   parameter Ohms#("drain resistance") dr from [0:inf);

   parameter Ohms#("source resistance") sr from [0:inf);

>There are also probably a good 40 different units used in BSIM3,
>if you consider some are straight values, some are per unit width,
>some are per unit area, and some even have fractional units because
>they're part of a pow() expression. I don't think it's reasonable
>to make the user `define 40 different expressions that will be
>(a) unique and (b) easy to understand as you read through the
>source code.
>
>
>>Then you can do -
>> `define OHMS (*units="Ohms"*)
>> `define RES (*description="Resistance"*)
>> ...
>> parameter real `OHMS `RES from [0:inf);
>>
>>
>
>No, you can't; you have to do
> `OHMS (*desc="drain resistance"*) parameter real rd from [0:inf);
>because attributes have to go first on the line.
>
>
>-Geoffrey
>

Alright -

        `define OHMS (*units="Ohms"*) real
        ...

        parameter `RES `OHMS rx from [0:inf);

You can then change the defs to something else for SV e.g.:

    `ifdef __SYSTEM_VERILOG__
    `define OHMS
    `define RES Ohms#("Resistance")
    `endif

BTW, I notice Laurent proposed the same syntax change for attributes.
 
Kev.

-- 
Kevin Cameron, CPU Technology, CA 94588, Tel.: (925) 225 4862