Assertion based Verification in TLM

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Assertion based Verification in TLM

• Amirali Ghofrani
• Negin Javaheri

East West Design and Test Symposium09
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Outline

• Verification
• Assertions
• The road map
• SystemC Assertions
• TLM Assertions
• Simple Assertions
• Static Assertions
• Dynamic Assertions
• Next steps!
• Summary

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Why to do verification?

• Number of transistors on a chip increases
  approximately 58 per year, according to Moore's
  Law
• The design productivity, facilitated by EDA tool
  improvements, grows only 21 per year
• Functional errors form 43 of all errors in the
  designs
• Undetected faults costs so much for the companies
  in terms of redoing the chip, replacing the
  faulty device, and the most important of all
  regaining customers confidence
• statistics were extracted from SIA road map and
  one of synopsis surveys

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Verification Categorization?

• Can be divided from many point of views
• Levels of abstraction
• Gate Level
• RTL
• TLM
• Methods
• Formal
• Simulation based
• Hybrid!
• Assertion based

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Assertion

• Assertion is the characterization of a designs
  behavior
• Advantages
• Increased observability
• Faster debugging
• Reusability
• Similar designs
• Different levels of abstraction
• Different assertion languages PSL, OVL, SVA,

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The road map
SystemC Assertions
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SystemC Assertions

• Why SystemC assertions
• SystemC was chosen as the primary language to
  describe the new higher levels of abstraction
• Unlike HDLs, no specific assertion set was
  provided for SystemC
• OVL like Assertions defined in SystemC
• Same Functionality
• Same arguments
• Same parameters
• Same coverage calculations
• Useful for
• RTL and mixed TLM-RTL designs
• TLM computational modules

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TLM Assertions

• Uses OSCI TLM1.0 library
• Provides verifiable communicational channels
• Implemented as SystemC functions within TLM1.0
  library
• Can be called whenever the desired channel is
  accessible
• Categorized into 3 groups
• Simple
• Static
• Dynamic

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Simple Assertions
Assert_nbput() has been fired.

• Some examples
• Assert_full
• Assert_nbput
• Assert_blocking

Assert_blocking() has been fired.
Run!!!
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Static Assertions

• Static Parameters
• Start time
• End time
• Number of transactions
• Limit on the number of FIFO blocks

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Static Assertions- Cont.

• Examples
• Assert_Overflow(limit)
• Assert_num_nbput_time(stTime, EndTime, limit)

Putting three data into the channel
Putting one data into the channel
Assert_overflow(3) has been fired.
Run!!!
Assert_nbput_limit_time(30000,90000,2) has been
fired.
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Dynamic Assertions

• Dynamic Parameters
• Getting some signal as input port
• Port binding is needed
• Static Parameters
• Like before!
• Examples
• Assert_no_same_data_nbput

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Dynamic Assertions- Cont.
Writing the desired value in parameter
Run!!!
Specifying the desired dynamic assertion
Binding and passing the appropriate port to the
input parameter of assertion
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Can we live happily ever after?

• NO!
• TLM2.0 has arrived!
• Functional coverage
• Add more assertions and complete the set!

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Summary

• Verification of TLM components
• TLM assertions for Communicational
• SystemC assertions for Computational