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adrianj / RangeImaging

Various things related to range imaging - specifically the Victoria University PMD19k Range Imaging System
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PMD Cyclone3 - PLL control #2

Open adrianj opened 14 years ago

adrianj commented 14 years ago

The reconfigurable phase-locked-loops on the Cyclone 3 are slightly different to those on the stratix 3 that this design has been ported from. The mod_homodyne_c3, pll_control_c3_full and pll_reconfig_full_c3 are the modified source files to implement the changes. Also some small changes have been made to phase_controller and frequency_controller to be able to work with both. Current known issue is with frequency_controller in that the scan chain is not correct. Need to fix:

  1. The value for the N counter so that it is reasonable (currently way too high!)
  2. The value for the M counter is not being loaded correctly.
  3. Appropriate values for the constant loop filter, loop capacitance, etc. have not been set.

With inappropriate values for these the pll fails to lock (at least in simulation) - making things pretty useless.

adrianj commented 14 years ago

Issue appears to be fixed in simulation. Still needs to be tested in hardware.