X-Authentication-Warning:	delorie.com: mail set sender to geda-user-bounces using -f
X-Recipient:	geda-user AT delorie DOT com
Subject:	Re: [geda-user] was XML file format (parametric sheets, sub circuits)
To:	geda-user AT delorie DOT com
References:	<20151220120219 DOT c4644eef1a65b0eb2fb60d76 AT gmail DOT com>
	<20151220122659 DOT 378AF809D791 AT turkos DOT aspodata DOT se>
	<20151220120219 DOT c4644eef1a65b0eb2fb60d76 AT gmail DOT com>
	<20151220125839 DOT 10228 DOT qmail AT stuge DOT se>
	<20151220133436 DOT 0B120809D791 AT turkos DOT aspodata DOT se>
	<20151220163208 DOT 1eb958feaaf024a483526fab AT gmail DOT com>
From:	"Dan McMahill (dan AT mcmahill DOT net) [via geda-user AT delorie DOT com]" <geda-user AT delorie DOT com>
Message-ID:	<567775EB.4050500@mcmahill.net>
Date:	Sun, 20 Dec 2015 22:45:47 -0500
User-Agent:	Mozilla/5.0 (Windows NT 6.3; WOW64; rv:38.0) Gecko/20100101
	Thunderbird/38.4.0
MIME-Version:	1.0
In-Reply-To:	<20151220163208.1eb958feaaf024a483526fab@gmail.com>
X-Original-DKIM-Signature:	v=1; a=rsa-sha256; c=relaxed/relaxed; d=comcast.net;
	s=q20140121; t=1450669561;
	bh=eqbuGmpO9winSOVEm+jrJBnKOQQoGuZH+gRqxxByc/Q=;
	h=Received:Received:Subject:To:From:Message-ID:Date:MIME-Version:
	Content-Type;
	b=YThWk/ZdQdiXMw6xPP2RFDDtdrkeelr0Hq9rWG7iJ1+ob4wokcPMDJiAHW00Az+uc
	POobBT09/YV6cx9kvW/qXpb+CQI6dqkgV3YCTTYxzWjK6h7IYdKqUkwT0NIXKH1EMK
	x8K0rUpeyVjFEwiw8hGNHzqTiNUi9RbagzNithA9pOp81jeITbQMo7gTQ9mV0fu7P6
	vFawKMMwE6bzaiRYa6d/L8o/gE11J+mVOF4Xyp387/KozYKKoALJiYe1gbLM3JOhVv
	pGHww5+uL2HoeK652237wFWy5NZ/YcAdtcyEsaYhobjdXY5wazMgFa/ZMNl118Q/Yx
	mut8Mbc2YGOfg==
Reply-To:	geda-user AT delorie DOT com
Errors-To:	nobody AT delorie DOT com
X-Mailing-List:	geda-user AT delorie DOT com
X-Unsubscribes-To:	listserv AT delorie DOT com

On 12/20/2015 10:32 AM, Nicklas Karlsson (nicklas DOT karlsson17 AT gmail DOT com) 
[via geda-user AT delorie DOT com] wrote:
>> I'd like to be able to do, gschem:
>>
>> . give parameters to subsheets, like
>>    output is to be 12V select suitable resistor devider
>>    this filter has this freq., select suitable components
>>
>> there should be no reason that I must copy the sheet and exchange a few
>> small values
>
> It would definitely make sense for filters and others with parameters but how to implement something easy to understand and use i have no idea.

It is also extremely useful in flows where you are running simulations 
of things.  For example, you might come up with a model topology for 
something you want to model and then use that cell in multiple different 
places with different parameters.  This may or may not be intended to 
drive a layout.

One way for this to work from a user point of view is the following: 
Suppose your schematic is something where you are just changing RLC 
values.  You have elements with attributes like value=10k, value=100p, 
etc.  Change those to be something like value=param('R1'), 
value=param('C2').  Now implement a mechanism where a symbol for this 
cell has attributes named R1, C2, etc that are passed down the hierarchy.

Now here comes one of the sticking points.  We should be able to handle 
this from the netlisting side.  It is nice though to be able to descend 
through schematic hierarchies and display either the string literal like 
param('R1') or to have it evaluate the expression and show that.



>
>> Pcb:
>>
>> . make theese things a group
>>    set values (e.g. refdes) from paramaters
>>    move everything in the group as one, like it remebers selections
>
> Yes sub circuits or sub layouts make sense. What would be needed is a selector to select to which sub layout added objects will belong, default sub layouts would probably be sub sheets. Then they belong to a sub layout they could be selected and moved or replaced with a modified copy. I have made two circuits boards there I copied and reused same layout data the last months.
>
> I think a selector to select sub layout would be rather simple to implement although I looked into file format and do not think it is possible to add the necessary information to objects or list of objects without a change of file format.
>

I would really like to see PCB support hierarchical layouts.  Here are a 
few reasons

- multiple, identical, channels for audio, or other data acquisition. 
If they are supposed to be the same, why not have them truly be the 
same.  Only do the layout once and have it propagate to all other 
instances.  Yes, you can screw up the notion of "truly the same" by 
blowing it with power ground connections being different or other issues 
but at least you're confident the inside is right.

- a microstrip filter or combline filter or other such block where the 
layout is the circuit (or an important part of the circuit).  You may 
want to complete this layout and then have it available to move around 
as a completed block.  You certainly don't want to accidentally get 
inside and mess up a microstrip resonator!

- blocks that may have a higher reuse potential.  Maybe you have an 
audio tone control circuit that you're planning on using in a number of 
amps or preamps.  It may be nice to either directly point at the same 
block or more easily spin off a self contained module for it.

- It helps with floorplanning on complex layouts.  You may find that a 
block needs to grow and it can be easier to move over some larger self 
contained blocks.

That said, there would be a number of issues to sort out to get it 
implemented and working correctly.  As a note, that is just standard 
practice in any IC layout.

-Dan

- Raw text -