MIPI DevCon 2016: Using MIPI Conformance Test Suites for Pre-Silicon Verification

Using MIPI Conformance Test Suites for pre-silicon

verification

Ofir Michaeli MIPI VIP R&D Team Leader Cadence Design Systems, Inc.

Agenda •  Compliance Verification Concerns • MIPI CTS – what is it? •  Pre-Silicon verification principles •  The 4 steps for Compliance testing •  Using the MIPI CTS for pre-silicon verification

•  Lesson learned from real life projects

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Compliance Verification Concerns •  “How do we know that all spec related scenarios have

been covered?” •  “How do we create tests to cover all these scenarios?” •  “After running the tests, some areas are still not

covered. How do I retarget the tests to fill the holes?” •  “The spec has changed, how do I apply the change

while ensuring nothing has broken?”

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MIPI CTS – what is it? •  List of tests that complements the specification and

enables measurement of conformance •  Used for interoperability testing at official Lab (Post

Silicon) •  Covers all specification main flows •  Product must pass conformance testing to be on the

Integrators List •  NOT a comprehensive verification plan

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MIPI CTS – what is it?

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UniProExample

Purpose

Specref

Testscenario

Expectedresults

! SW model, based on the MIPI specification !  Designed to run against RTL implementation at cycle

accurate level

Pre-Silicon Verification of standard interface

Simulation (SW)

Verification/ Design engineer

HW Simulator Engine PCIe model/VIP

‘Physical view’

Copyright © 2012, PCI-SIG, All Rights Reserved

MIPI

The Four Steps to Compliance •  Based on MIPI Specification

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Defineandrefineyourcompletenesscriteriabasedonthespec/CTS

Createself–checkinglogicinyourtestbench

CreateintelligentsAmuligenerator

AssessandreportstatusofcompletenessDone?


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Defining completeness criteria based on MIPI CTS (MIPI D-PHY example)

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Whatdoesittaketoverifyit?

Defining completeness criteria based on MIPI CTS (D-PHY example)

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VerificaAonplanforD-PHY

Escapemodescenarios

AllpermutaAonsrequiredtoensurecompliance

‘Grade’thatshowstheprogressbasedonactualtrafficoverthe

D-PHYinterface


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Self–checking logic: MIPI UniPro Example

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CTStest

if(result){if(should_set_rreq_bit_on_nac()){CDN_MIPI_UNIPRO_CHECK_THATerror_id=ERR_CDN_MIPI_UNIPRO_DLL108_NO_NAC_WITH_CLEARED_RREQ_WHEN_EXPECTED,condiAon=not(frame.direcAon==TRANSMITandframe.ctrl_id!=NACandshould_send_a_nac(CHECKING)andnac_sending_tolerance_passed()andshould_set_rreq_bit_on_nac()),spec_secAon="UNDEF",relevant_di=frame,err_msg=append("ShouldsendaNACframewithrreqbitcleared,butinsteadsending",frame);};

AutomaAcMonitorcheck


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Intelligent stimuli generator Example – MIPI D-PHY Example

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TestScenario:

1.  ConfiguretheTestSetuptotransmitavalidimageorvideosequencetotheDUT.

2.  ModifythesequencebyinserBnganLP-11/10/00/01/11invalidEscapeModeEntrysequencebetweenHSburstsontheDataLane(keepingallothernecessaryvideoBmingsintact,asneeded),andre-transmitthesequencetotheDUT.

3.  RepeatthepreviousstepforLP-11/10/11/11/11.

RandomizeInvalidEscapemodeandAming

RandomizeImage/Videosequencecontent

Randomizedifferentorders


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Assess and report status of completeness

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100%coverage?DONE!

Summary •  CTS are aimed for post silicon interoperability testing •  It can be leveraged for pre-silicon verification •  Use each CTS scenario as reference for the 4 steps for

compliance: •  Completeness criteria: executable and measurable •  Self–checking logic: Based on the expected results of the CTS

test •  Intelligent stimuli generator: to cover all relevant CTS scenarios •  Report status of completeness: To show clear view of the

progress for each CTS test

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MIPI DevCon 2016: Using MIPI Conformance Test Suites for Pre-Silicon Verification

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