Re: gEDA-user: Symbols: mixed slotted elements and dedicated pins?

[Steve Meier <smeier@xxxxxxxxxxxxxxxxxxx>]

If the power can be symetricaly distributed amoung the slots I just
mmake slotted symbols.

If the power can't or its a large device I make seperate power,
configurations and i/o bank symbols (even these can be split up) the
main point is that all symbols haveing the same refdes attribute will be
considered a single symbol for netlisting.

Steve Meier



John Luciani wrote:
> On Jan 29, 2008 4:25 AM, Richard Rasker <rasker@xxxxxxxxxx> wrote:
>
>   
>> Usually, I try looking up a symbol with a similar layout, but I got a
>> bit confused here. For example, there are two different CMOS 4053
>> symbols. The 4053-1.sym features separate dual-channel switches,
>> selectable by defining the slot. But how do I connect the Enable and VEE
>> pins (#6 and 7, respectively) to an arbitrary other component? And how
>> to connect the power pins? When I look into the .sym file, I see that
>> VDD, VSS and VEE have been defined as nets (with Enable tied to VSS --
>> which is not good). Does this mean that all VEE pins from multiple
>> 4053's are automatically tied together?
>>     
>
> It sounds like there is a mistake in 4053-1.sym.
>
> Nets that are named the same get connected. What I do for power pins is
> use a separate power symbol. Just make sure that both symbols have the
> the same refdes. For digital symbols I usually have a separate page (or section)
> for power symbols and the corresponding local decoupling caps.
>
> I have a script that takes symbols with embedded power nets and
> creates a series
> of power symbols and non-power symbols. The script is called
> create-np-symbols and is at
> http://www.luciani.org/geda/util/util-index.html
>
>   
>> How do I define this device as four slotted opamp elements with
>> dedicated standby and phantom ground pins? Or would I better create one
>> big, 16-pin symbol incorporating everything?
>>     
>
> You could make a four slotted op-amp symbol and a separate power/ground/standby
> symbol. When you place the symbols in your schematic just keep the
> refdeses the same.
>
> Depending on the amount of peripheral circuitry a 16-pin symbol could
> also work. If
> there is a lot of peripheral circuitry around each op-amp then I would
> do the two
> symbol approach.
>
> (* jcl *)
>
>   



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