Author Topic: PWR_FLAG vs input pin on 4027 JK FF  (Read 1289 times)

0 Members and 1 Guest are viewing this topic.

Online bd139

  • Super Contributor
  • ***
  • Posts: 9190
  • Country: gb
PWR_FLAG vs input pin on 4027 JK FF
« on: January 18, 2018, 11:35:48 pm »
I've got a 4027 which I've tied both Sd to ground on. gnd is marked with PWR_FLAG. This is an input pin in theory but the ERC is showing error as follows:



Schematic:



In theory the Sd pin should be both grounded and both inputs.

Any ideas how to proceed on this one to pass the ERC? Is this a bug in the symbol i.e. the pin should be an input?
« Last Edit: January 18, 2018, 11:37:59 pm by bd139 »
 

Offline fable

  • Regular Contributor
  • *
  • Posts: 63
  • Country: cs
Re: PWR_FLAG vs input pin on 4027 JK FF
« Reply #1 on: January 19, 2018, 12:34:03 am »
Edit library... Change the state of that pin
 
The following users thanked this post: bd139

Online bd139

  • Super Contributor
  • ***
  • Posts: 9190
  • Country: gb
Re: PWR_FLAG vs input pin on 4027 JK FF
« Reply #2 on: January 19, 2018, 12:54:05 am »
That did the trick. Bug in kicad library then!

Thank you :)
 

Offline hermit

  • Frequent Contributor
  • **
  • Posts: 469
  • Country: us
Re: PWR_FLAG vs input pin on 4027 JK FF
« Reply #3 on: January 19, 2018, 03:35:03 am »
That did the trick. Bug in kicad library then!

Thank you :)
The fact you ground them for your application doesn't make this a bug.  The data sheet I'm looking at says "1SD, 2SD
 9, 7 asynchronous set-direct input (active HIGH)".  Why would the library list it as a power pin?
 

Online bd139

  • Super Contributor
  • ***
  • Posts: 9190
  • Country: gb
Re: PWR_FLAG vs input pin on 4027 JK FF
« Reply #4 on: January 19, 2018, 05:00:50 am »
https://www.intersil.com/content/dam/Intersil/documents/cd40/cd4027bms.pdf

Page 6. IC schematic. Definitely inputs. Were marked as outputs in library.
 

Offline donotdespisethesnake

  • Frequent Contributor
  • **
  • Posts: 815
  • Country: gb
  • Embedded stuff
Re: PWR_FLAG vs input pin on 4027 JK FF
« Reply #5 on: January 20, 2018, 07:33:21 pm »
I found several issues like this when I reworked the CMOS library, it should be fixed in the latest version.
Bob
"All you said is just a bunch of opinions."
 

Online bd139

  • Super Contributor
  • ***
  • Posts: 9190
  • Country: gb
Re: PWR_FLAG vs input pin on 4027 JK FF
« Reply #6 on: January 21, 2018, 12:23:15 am »
Cool. Thank you  :-+
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf