Max PLLA for video generator?

Comments

• cgracey Posts: 14,280

  2009-03-20 14:48 edited 2009-03-20 14:48

  128MHz is no problem for the video generator.
  
  Feeding it data that fast·is the harder part.
  
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  Chip Gracey
  Parallax, Inc.
• Cluso99 Posts: 18,071

  2009-03-20 16:00 edited 2009-03-20 16:00

  Chip: I am presuming by your answer, we can run the prop up to 128MHz.
  If so, is it ok to use 8MHz xtal and PLLx16 or do we need to use a 16MHz xtal and PLLx8? Is there anything else we should be aware of if using these speeds?
  
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• Mike Green Posts: 23,101

  2009-03-20 16:10 edited 2009-03-20 16:10

  Chip is referring to the video generator and cog counters only. There is a separate PLL for this use and it and the counters can run much faster than the chip as a whole. You can run the Propeller's system clock at 128MHz if you're willing to refrigerate the chip. See the graph in section 10.2 of the Propeller datasheet.
• Cluso99 Posts: 18,071

  2009-03-20 17:18 edited 2009-03-20 17:18

  Thanks Mike. I haven't played with the video generator or counters, so I thought I must have missed something.
  
  ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
  Links to other interesting threads:
  
  · Home of the MultiBladeProps: TriBladeProp, SixBladeProp, website (Multiple propeller pcbs)
  · Single Board Computer·using the TriBladeProp board (ZiCog Z80 Emulator)
  · Prop Tools under Development or Completed (Index)
  · Emulators (Micros eg Altair, and Terminals eg VT100) - index
  · Search the Propeller forums (via Google)
  
  My cruising website is: ·www.bluemagic.biz·· MultiBladeProp is: www.bluemagic.biz/cluso.htm