The Designer's Guide Community
Forum
ForumVerilog-AMSAnalysisModelingDesignTheory
Welcome, Guest. Please Login or Register. Please follow the Forum guidelines.
Oct 18th, 2024, 2:19pm
 
  HomeHelpSearchLoginRegisterPM to admin    
The Designer's Guide Community Forum › Design › Mixed-Signal Design › PLL divider ratio
‹ Previous topic | Next topic ›
Pages: 1
Send Topic Print
PLL divider ratio (Read 3123 times)
chase.ng
Community Member
***
Offline



Posts: 77
penang/malaysia
PLL divider ratio
Apr 22nd, 2007, 2:00am  
Hi all,

I notice that most motherboards are having 14.318 MHz, anyone has idea what is the divider ratio to generate the system clock at 133 MHz/200 MHz?

thanks and regards,
chase
Back to top
 
 
Chase
View Profile chase.ng   IP Logged
mg777
Senior Member
****
Offline



Posts: 131
Re: PLL divider ratio
Reply #1 - Apr 22nd, 2007, 12:16pm  

The 14.318181... MHz is some multiple of the color subcarrier in TV's, and dates to when early computers used TV's as monitors.

To answer your question, 100 = 14.31818181... * 440/63

In practice there will be a ppm spec on the crystal, and a steady-state error in the PLL.
Back to top
 
 
View Profile   IP Logged
adesign
Community Member
***
Offline



Posts: 73
Re: PLL divider ratio
Reply #2 - Apr 25th, 2007, 9:47pm  
It also depends on the maximum divider settings allowed on motherboard.
Back to top
 
 
View Profile   IP Logged
Pages: 1
Send Topic Print
‹ Previous topic | Next topic ›
« Home ‹ Board
The Designer's Guide Community Forum » Powered by YaBB 2.2.2!
YaBB © 2000-2008. All Rights Reserved.
Copyright 2002-2024 Designer’s Guide Consulting, Inc. Designer’s Guide® is a registered trademark of Designer’s Guide Consulting, Inc. All rights reserved. Send comments or questions to editor@designers-guide.org. Consider submitting a paper or model.