Lab and Project Assignments

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Lab and Project Assignments
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Lab Assignment Clock skew and jitter measurements

• Hand PPT lab report.
• Activities
• Locate clock probe points on layout.
• Measures skew (at CPU0, CPU1, both P64H2s, MCH,
  and ICH) and Jitter at MCH.
• PPT minimum contents
• Hypothesis What you are measuring and why it is
  important.
• Results Summary Jitter and Skew
• Supporting data
• Illustrate where probes are placed
• Describe complete scope setup and threshold
  assumptions.
• Show all clock waveform super imposed on one
  graph.
• Determine skew from this
• Show simple jitter (infinite persistence) include
  picture of jitter.
• Describe issues with this simple jitter method.

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Project Assignment Simulation to Lab Correlation

• Goal Tune simulations to measurements
• Activities
• Locate DDR signal being probed.
• Determine all segments and component value.
• You may need to get component values from
  examining the board.
• Measure necessary DC voltages
• Modify the HSPICE DDR template file with actual
  values.
• Probe points
• One probe is on a data signal on the DIMM before
  the series resistor (End closest to DRAM chip)
• The other probe is on a the same data signal at
  the MCH.
• Capture a read signal at the MCH.
• Compare measured signal to simulated signal. You
  may need to bring into a spreadsheet and time
  shift data to get to over lap.
• Adjust elements in the simulation model achieve
  reasonable agreement with measurements. You need
  to define what reasonable is and justify that.
• PPT minimum contents
• Hypothesis Simulation model accurately predict
  real circuits.
• Results Summary
• Overlay of simulation and measurement waveforms.
• Overivew of component changes that had the most
  effect on achieving the best results.
• Supporting data

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Starter Schematic For DDR Simulation