gEDA-user: Hierarchical Design

[Die.Kaisers@t-online.de (Familie Kaiser)]

Hi,

I am just creating my first hierarchical design with gschem. Unfortunately I 
found not match documentation about that.

With the examples I figured out the following way. My question to the 
developer of this fabulous program is, whether this is the official way:




1. Upper level

Create a symbol somewhere along the "component-library" search path, defined 
in gschemrc. The name of the symbol should be the same as the name of the 
lower level schematic, but with the extension "*.sym":

<lower_level_schematic_name.sym>


Place the following attributes on the symbol:

source=<lower_level_schematic_name.sch>, visible or invisible
refdes=X?, visible

Attach the the following attributes to each pin of the symbol:

pinlable=<signal_name>, visible
pinnumber=1, 2, IN, Out, ...;  comment only
pinseq=1, 2. ...; invisible, comment only


Place the symbol in the upper level schematic.




2. Lower level

Create a new schematic called <lower_level_schematic_name.sch>. This must be 
in the somewhere in the "source-library" search path defined in gschemrc. 
Example definition:

(source-library ".")


Use the symbol "in-1" or "out-1" form the library "IO", connect it to a net.
Change the value of the refdes attribute to <signal_name>. The signal name 
must be the same as the pinlable propertys on the previous crated symbol.


Alternatively you can create your own symbol. The symbol needs one pin with 
the following attributes:

refdes=<signal_name>; visible

optional:
device=input, output, ...; invisible.

pin attributes:
pinnumber=1; invisible
pinseq=1; invisible




3. Netlist extraction

make sure that you use the same search path in gnetlistrc than in gschemrc. 
Then use gnetlist in your usual way. To get more information about what 
gnetlist is doing use the "-v" option.



-- 

----------------------------------------
die.kaisers@t-online.de
                                            oder
dh0may@darc.de
                                            oder
http://www.darc.de/c/12
---------------------------------------