6 DAC RCA connectors on A9 board

Comments

• evanh Posts: 16,835

  2016-02-15 02:42

  Just having a squiz at the physical pinout and, surprise, the second three DACs are on the same group of 30 pins as the first three DACs. Only the clock differs ... which in turn mean on Cog0, DAC3 is time multiplexed with DAC0 (Assuming Cog0 does have four DACs assigned).
  
• Tubular Posts: 4,747

  2016-02-15 02:49

  Yes one of the differences in going from A7 to A9 was _losing_ something like 16 gpio, hence the data bus sharing.
  
  Certainly seems to work just fine.
  
• cgracey Posts: 14,287

  2016-02-15 04:12 edited 2016-02-15 04:16

  I need to constrain Quartus to output to the DAC pins quickly, so that we can get six unique channels out.
  
  Right now, pins 1, 2, and 3 are DAC-capable. The DAC on pin 0 is used as HSYNC, where any non-zero value on pin 0's DAC causes HSYNC to go high. DAC 0 is not available as analog, in other words, but DACs 1, 2, and 3 are.
• potatohead Posts: 10,261

  2016-02-15 05:20

  Ok. No worries, and thanks for clearing that up.
  
  I'm good with what we have right now.
  
  I should be able to just limit the streamer output, and drive one of the three channels with the COG, yes?
  
  
• cgracey Posts: 14,287

  2016-02-15 05:24

  potatohead wrote: »

  Ok. No worries, and thanks for clearing that up.
  
  I'm good with what we have right now.
  
  I should be able to just limit the streamer output, and drive one of the three channels with the COG, yes?
  

  
  Yes.
• potatohead Posts: 10,261

  2016-02-15 05:26

  Cool beans.