Re: gEDA-user: gnetlist -g drc2 and pintype
kai-martin knaak wrote: Karl Hammar wrote: Running gnetlist -g drc2 on a schematic I get: input/output -- pwr input and output are meant to refer to signals. The DRC assumes that signals should never be connected to power lines. With analog circuits there is no strict dividing line between signal and power. So DRC should be taken with a large grain of salt on these circuits. From what I know, it's a bad idea to leave logic inputs floating, so on TTL/CMOS gates, one will tie them to GND if not used. GND is a power line, isn't it? ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: gnetlist -g drc2 and pintype
Tying a digital input directly to a power rail is a bit like doing a crossword puzzle in ink. You need a lot of confidence to do that in a real design. I typically use a resistor to pull them up or down. That can always be hacked, power connections can be hard to access to modify them. Rick At 09:22 AM 9/27/2010, you wrote: kai-martin knaak wrote: Karl Hammar wrote: Running gnetlist -g drc2 on a schematic I get: input/output -- pwr input and output are meant to refer to signals. The DRC assumes that signals should never be connected to power lines. With analog circuits there is no strict dividing line between signal and power. So DRC should be taken with a large grain of salt on these circuits. From what I know, it's a bad idea to leave logic inputs floating, so on TTL/CMOS gates, one will tie them to GND if not used. GND is a power line, isn't it? ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: gnetlist -g drc2 and pintype
Hi Karl, El dom, 26-09-2010 a las 11:33 +0200, Karl Hammar escribió: [snip] Checking pins without the 'pintype' attribute... Checking type of pins connected to a net... WARNING: Pin(s) with pintype 'output': U2:9 are connected by net 'unnamed_net61' to pin(s) with pintype 'input/output': U1:30 WARNING: Pin(s) with pintype 'output': U2:7 are connected by net 'unnamed_net55' to pin(s) with pintype 'input/output': X1:9 WARNING: Pin(s) with pintype 'output': U3:3 are connected by net 'Vcc' to pin(s) with pintype 'input/output': Q8:A1 Q7:A1 Q6:A1 Q5:A1 ERROR: Pin(s) with pintype 'output': U3:3 are connected by net 'Vcc' to pin(s) with pintype 'power': U2:16 U1:6 U1:4 U1:18 WARNING: Pin(s) with pintype 'input/output': Q8:A1 Q7:A1 Q6:A1 Q5:A1 are connected by net 'Vcc' to pin(s) with pintype 'power': U2:16 U1:6 U1:4 U1:18 Checking unconnected pins... ERROR: Unconnected pin U2:11 [snip] Type of pins Why does it warn about output -- input/output input/output -- pwr Because drc2 can't check if an input/output pin is really an input or an output (or even both, depending on the design). It gives you warnings (not errors) about this, so you can check by your own. It tries to catch errors like connecting an output to another output, or an output to a power rail. Drc2 is not perfect, and has limitations, but it's all we have by now. The ERROR is a lm7805's output (U3:3) connected to other pins of type pwr. How do I make it accept that? There is no concept like pwr in or pwr out, so just giving it the pwr pintype should be ok. [snip] The unconnected pins can be left unconnected, how can I make it accept that? If you connect them to a special nc (no connection) symbol, drc2 will ignore them. Best regards, Carlos ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: gnetlist -g drc2 and pintype
kai-martin knaak wrote: The unconnected pins can be left unconnected, how can I make it accept that? I don't know. I put my own nc.sym at pins that are deliberately not connected. This symbol contains just one pin and no net. However, DRC still complains, because the generated net is connected to only one pin. How about a special net no_net to deal with this situation? This net would be ignored for generation of the net list. Update: There are already not-connected symbols in the default library. The following symbols live in the misc department: nc-bottom-1.sym nc-top-1.sym nc-right-1.sym nc-left.sym The drc2 backend ignores them and does not throw errors, or warnings. The magic is achieved by: device=DRC_Directive value=NoConnection graphical=1 I combined this magic with the zero pin size trick John D. told about in the other thread, to get a simplified nc-symbol. http://www.gedasymbols.org/user/kai_martin_knaak/symbols/power/nc.sym ---)kaimartin(--- -- Kai-Martin Knaak Öffentlicher PGP-Schlüssel: http://pgp.mit.edu:11371/pks/lookup?op=getsearch=0x6C0B9F53 ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
gEDA-user: gnetlist -g drc2 and pintype
Running gnetlist -g drc2 on a schematic I get: Checking non-numbered parts... Checking duplicated references... Checking nets with only one connection... Checking pins without the 'pintype' attribute... Checking type of pins connected to a net... WARNING: Pin(s) with pintype 'output': U2:9 are connected by net 'unnamed_net61' to pin(s) with pintype 'input/output': U1:30 WARNING: Pin(s) with pintype 'output': U2:7 are connected by net 'unnamed_net55' to pin(s) with pintype 'input/output': X1:9 WARNING: Pin(s) with pintype 'output': U3:3 are connected by net 'Vcc' to pin(s) with pintype 'input/output': Q8:A1 Q7:A1 Q6:A1 Q5:A1 ERROR: Pin(s) with pintype 'output': U3:3 are connected by net 'Vcc' to pin(s) with pintype 'power': U2:16 U1:6 U1:4 U1:18 WARNING: Pin(s) with pintype 'input/output': Q8:A1 Q7:A1 Q6:A1 Q5:A1 are connected by net 'Vcc' to pin(s) with pintype 'power': U2:16 U1:6 U1:4 U1:18 Checking unconnected pins... ERROR: Unconnected pin U2:11 ERROR: Unconnected pin U2:12 ERROR: Unconnected pin U2:13 ERROR: Unconnected pin U2:14 ERROR: Unconnected pin U1:13 ERROR: Unconnected pin U1:19 ERROR: Unconnected pin U1:20 ERROR: Unconnected pin U1:22 ERROR: Unconnected pin Q8:22 ERROR: Unconnected pin Q8:12 ERROR: Unconnected pin Q7:22 ERROR: Unconnected pin Q7:12 ERROR: Unconnected pin Q6:22 ERROR: Unconnected pin Q6:12 ERROR: Unconnected pin Q5:22 Checking slots... Checking duplicated slots... Checking unused slots... Found 4 warnings. Found 16 errors. *** Type of pins Why does it warn about output -- input/output input/output -- pwr The ERROR is a lm7805's output (U3:3) connected to other pins of type pwr. How do I make it accept that? *** The unconnected pins can be left unconnected, how can I make it accept that? Regards, /Karl Hammar - Aspö Data Lilla Aspö 148 S-742 94 Östhammar Sweden +46 173 140 57 ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
Re: gEDA-user: gnetlist -g drc2 and pintype
Karl Hammar wrote: Running gnetlist -g drc2 on a schematic I get: (...) Why does it warn about output -- input/output Don't know. IMHO, this combination should be fine. input/output -- pwr input and output are meant to refer to signals. The DRC assumes that signals should never be connected to power lines. With analog circuits there is no strict dividing line between signal and power. So DRC should be taken with a large grain of salt on these circuits. The ERROR is a lm7805's output (U3:3) connected to other pins of type pwr. How do I make it accept that? Make the output pin of the LM8705 type pwr, too. The unconnected pins can be left unconnected, how can I make it accept that? I don't know. I put my own nc.sym at pins that are deliberately not connected. This symbol contains just one pin and no net. However, DRC still complains, because the generated net is connected to only one pin. How about a special net no_net to deal with this situation? This net would be ignored for generation of the net list. ---)kaimartin(--- -- Kai-Martin Knaak Öffentlicher PGP-Schlüssel: http://pgp.mit.edu:11371/pks/lookup?op=getsearch=0x6C0B9F53 nc.sym Description: application/geda-symbol ___ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
