Schedulingbased Testcase Generation for Multimedia SoCs

1
Scheduling-based Test-case Generation for
Multimedia SoCs

• Amir Nahir (speaker)
• Avi Ziv
• Roy Emek
• Tal Keidar
• Nir Ronen

2
Outline

• Characteristics of Multimedia SoCs
• Our test case the DVD Player SoC
• Existing solutions
• Modeling
• Scheduling
• Experimental results

3
Characteristics of Multimedia SoCs

• Multiple cores with different functionalities
• Encoders, Decoders, DSPs
• Single controller
• Executes the SoCs embedded software
• Controls and coordinates the various cores
• Pipeline-like processing of input items

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The DVD Player SoC
Memory
Memory
Memory
DeMux
VDU
MDU
ISR
ISR Input Stream Reader DeMux
De-Multiplexer MDU MPEG Decode Unit VDU Video
Display Unit
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The truth is a little more complicated
MPEG2 Frames
 
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
B
I
 
 
 
 
 
 
 
 
 
 
 
B
P
ISR
B
I
 
 
 
 
 
 
 
 
 
B
P
 
 
DeMux
B
I
 
 
 
 
 
 
 
B
P
 
 
 
 
MDU
P1
P2
P1
P2
P1
B1
B2
 
 
 
 
 
 
 
 
VDU
B1
B2
I1
I2
Video Fields
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Existing Solutions

• Manually writing tests
• Highly complex
• Highly error prone process
• Traditional system level test benches
• Focus on generating stimuli for a complete system
• Hard to define and create a required internal
  event
• SW/HW Co-verification
• SW still not ready
• Limits verification couples with SW version
• Hard to reach corner cases

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SoCVer a model-based random test case generator
System (DUV) model
Agents
Abstract Operations
SoCVer main engine
Scheduling problem solver
Test-template
Input meta-file
Used as software for the SoCs controller
Test case
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Modeling
CPU
ISR
VDU
MDU
DeMux
DRAM
MDU
VDU
ISR
DeMux
DeMux Rule
MPEG2 Rule
VDU Rule
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Scheduling

• At the core of the test generation are scheduling
  problems representing the time in which the DUTs
  agents (cores) process the different input
  items (MPEG2 frames)
• The scheduling problems are formulated as
  Constraint Satisfaction Problems (CSPs)
• Using a well known reduction, enhanced with some
  unique characteristics

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Experimental Results

• Modeling of DVD Player SoCs basic operations
• Automatic generation of test cases for Play
  Pause sequences
• Including variations
• Zoom parameters
• On-Screen-Display parameters

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Incorporating randomness and testing knowledge
Requires less than one minute to generate
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Summary

• Using the SoC's main controller point of view for
  controlling the flow of data in the SoC
• Model based tool tailoring for new designs
  requires less efforts
• Preliminary results are promising