PSP 101.0 Evaluation

1
PSP 101.0Evaluation

• CMC Update
• Circuit Simulation Results
• Agilent EEsof EDARick Poore
• 8 May 2006

2
Circuit Simulation with PSP

• MCNC CircuitSim90 mos2_large test suite of 14
  circuits modified to work with the IBM 90 nm
  models
• Voltage sources changed to 1.5V instead of
  original 3V or 5V
• Each circuit used 1 NMOS and 1 PMOS model
• easily changed to use the IBM 90 nm models
• device sizes and other parameters were not
  changed
• Contact me if you would like the netlists
• Original PSP100 model cards were updated to
  PSP101
• 49 parameter names changed
• 13 parameters deleted due to major model changes
• If anyone has a better mapping, Id like to have
  it
• 2 transient simulations were performed using ADS
  2005A for each circuit
• BSIM 4.30 C-code model in ADS
• PSP 101.0 SiMKit 2.3 model (ADMS to SiMKit
  translator)

3
PSP 101 versus BSIM4
With Swjuncap1 Swigate1,compared to BSIM4, PSP
takes 1.03x more timesteps 0.99x more
iterations per timestep 2.00x more time per
device evaluation 2.06x more time for
transient simulation With Swjuncap0
Swigate1, compared to BSIM4, PSP takes 1.62x
more time for transient simulation
4
PSP 101 versus BSIM4 Swjuncap1

• Time measured is that just for transient analysis
  (no readin, DC time)
• PSP 101 is 2.06x slower than BSIM4.30

5
PSP 101 versus BSIM4 Swjuncap1

• Number of timesteps and iters/timestep are
  similar
• us/device tran time / iterations / mosfets (in
  microseconds)
• Time per device iteration is 2.00x slower

6
Profiling

• Intels Vtune was used to profile add20 in ADS
  2005A on Linux
• BSIM4 and PSP run times are dominated by device
  evaluation, not matrix solver, transient solver,
  or other device code
• log(), exp() and pow() are expensive functions
• account for 36 of BSIM4 evaluation
• account for 39 of PSP evaluation

7
PSP 101 is really 6 models

• BSIM4.50 provides everything in one model
• scalable, binning, NQS
• PSP 101 Verilog-A code defines 6 different high
  level models
• psp101e (1) electrical (no W/L),
  quasistatic (4) electrical, NQS
• psp1010 (2) scalable (W/L), quasistatic (5)
  scalable, NQS
• psp1011 (3) binning (W/L), quasistatic (6)
  scalable, NQS
• Wed like to see this reduced to just 2 models
  similar to BSIM4.50
• combine quasistatic and NQS into one code stream
  so NQS can be an instance flag instead of a
  model property
• combine scalable and binning parameters sets
  into same model
• That would give
• (1) electrical (no W/L) QS or NQS is an
  instance parameter
• (2) scalable (W/L) binning parameters are
  included but default to off QS or NQS is
  an instance parameter