RedHawk™-CPA Chip-Package Co-analysis

RedHawk™-CPA
Chip-Package Co-analysis
Design Automation Conference 2014
6/23/2014
© 2014 ANSYS, Inc.
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Design Trends and Challenges
Supply vs FOM Delay
Operating voltage
Threshold voltage
Source: ARM FinFET Study 2013
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Lower operating voltage
Tighter operating margins
ITRS Trends, 2012
Demand Current
Supply Current
High power
Low power
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The Move to FinFET Nodes:
Increased Chip Functionality:
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© 2014 ANSYS, Inc.
Increasing number of voltage domains
Power density variations
Increasing operating modes
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Need for Accurate Package Models
Package Model for Noise Analysis:
Green = Current from battery w/o pkg
Red = Current from battery w/ pkg
• Model inductive components
• Model di/dt events accurately
• Model high and low frequency effects
Die
Package
V(t)
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-
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Supply
Lpkg
Rpkg i(t,V)
Rdie
Cpkg
Cdie
© 2014 ANSYS, Inc.
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Full CPS Analysis
32nm CMOS Design
Transient Analysis
Package Modeling Importance
Without Package
With Package
• Analysis with and without package shown
• Package has significant impact on chip voltage
6/23/2014
© 2014 ANSYS, Inc.
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RedHawk-CPA
Chip-Package Co-Analysis Platform
Package modeling for
on-die analysis
6/23/2014
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Accurate per-bump package model for IC analysis
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Tight integration with RedHawk platform
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Enables package voltage drop analysis
© 2014 ANSYS, Inc.
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RedHawk-CPA Overview
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Package Model Generation Customized for RedHawk
– High bump resolution
– Model power/ground supplies independently
– Fast and accurate
– Automatic hook-up and import into RedHawk
– Direct import of package layout
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IC-Package Co-Analysis
– Support for IR, DvD and power-up analysis in RedHawk
– DC-IR Static analysis of package
– AC-hotspot analysis of package
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© 2014 ANSYS, Inc.
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RedHawk-CPA
Accuracy
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Extraction engine uses 3D full-wave technology
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Optimized for IC-Package co-simulation
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Per-bump resolution
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Correlated with reference electromagnetic solvers
Proprietary meshing technology
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Correlation with 3D solvers
© 2014 ANSYS, Inc.
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Physical vs S-Parameter Models
RedHawk-CPA (RLCK Model)
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Thousands of bumps can be modeled
Separate power and ground networks
Accurate for PDN frequency components
Physical model
S-Parameter (3D-FW Model)
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Limited to tens of ports
Folded ground/power networks
Appropriate for signal integrity analysis
Behavioral model
Die Analysis
6/23/2014
Package SI/PI Analysis
© 2014 ANSYS, Inc.
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Power and Ground Noise Modeling
Power and Ground Model Requirement
Board
Package
Chip
CPA Model
RedHawk
planes
other components
capacitors
DvD Analysis Requirements
VDD Drop
VSS Drop
– Power and ground networks to be analyzed
– Ground bounce through package impacts
ground bounce on die
– Net based and instance based drops
6/23/2014
© 2014 ANSYS, Inc.
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RedHawk-CPA Analysis Flow: Model Import
Pkg Database
3D FEM PKG
Extraction
IC Database
Chip Package
RedHawk
Co-simulation
Die-Package Hook Up using GUI:
IR, DvD, Power-up
Package Bumps
– Automatic connection using PLOC
– PKG-DIE transformations done
– One click die hook up
6/23/2014
RedHawk PLOC
© 2014 ANSYS, Inc.
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RedHawk-CPA Performance
Setup
Runtime
#Terminals
6 layer package / 3 domains
10min (~15GB)
600
18 layer package / 6 domains
15hrs:20min (~100GB)
~3000
Enabling Technologies
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Multi-core solver
Adaptive meshing
© 2014 ANSYS, Inc.
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RedHawk-CPA Analysis Flow: Co-simulation
Pkg Database
3D FEM PKG
Extraction
IC Database
Chip Package
RedHawk
Co-simulation
Package Robustness
Metrics
Chip-Aware Package
AC/DC Hotspot
RedHawk Explorer Results
Package/Die Co-visualization
6/23/2014
Package-Aware
IR/DvD
© 2014 ANSYS, Inc.
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Package Robustness Metrics
Bump/Pin RL
– Highlight bumps with relatively large
resistance or inductance
– Overlay results with package layout to find
routing weak points
Impedance Analysis
– Per bump impedance
– Impedance vs frequency analysis
6/23/2014
© 2014 ANSYS, Inc.
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Chip-Aware Package DC and AC Hotspot
DC-Hotspot
– IR drop across package planes
– View voltage, currents
– View individual layers including bumps/balls
AC-Hotspot
– AC voltage/current as function of frequency
– Automatic or user driven frequency points
– EMI near/far field views
6/23/2014
© 2014 ANSYS, Inc.
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Case Study: Per-Bump Accuracy
Bump Voltage from RedHawk DvD Analysis
Lumped
Per-bump Model
Per-bump CPA model shows voltage
variations on bumps
13.8mV (Uniform)
19.2mV
Instance Voltage Distribution
Veff No PKG
Veff Lumped PKG
Veff Distributed PKG
Instance voltage distribution shows larger variations
using the distributed per-bump model
RedHawk-CPA highlighted weakly connected bumps !!
6/23/2014
© 2014 ANSYS, Inc.
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Case Study: RedHawk-CPA
– Not all cores were able to meet specified speed
Silicon Measurements
– Silicon measurement showed voltage gradient
across cores to be the cause
Cores 0/1 faster
than cores 2/3
– Simulations with RedHawk-CPA high resolution
package model correlated with measurement
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61mV simulated vs. 50mV measured voltage
difference (core3 – core1)
Core
1
Core
3
RedHawk-CPA Results
Core
0
Core
2
Source: Mahesh Sharma et al., “Unified method for package-induced power
supply droop”. Design Automation Conference 2013, Designer Track
6/23/2014
© 2014 ANSYS, Inc.
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Summary
Enabling IC/Package Co-analysis Using RedHawk-CPA
IC Database
Pkg Database
RedHawk-CPA
3D FEM Package
Extraction
IR, DvD, Power-up
Streamlined
Package/Die Setup
IC-Package
Co-Analysis
Package Pin
Inductance/R Maps
Accurate Voltage Gradient
Across Bumps
Independent Power/Ground
Analysis with Package
6/23/2014
HTML Report of Analysis
© 2014 ANSYS, Inc.
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