Victor Sanchez-Rico, project manager MIPI at BitifEye Digital Test Solutions GmbH, highlights the challenges observed and the lessons learned from BitifEye's experience with testing of high-speed digital interconnect busses, with a focus on the complex high-speed electrical PHY layer receiver conformance tests.

1. Victor Sanchez-Rico
BitifEye Digital Test Solutions GmbH
PHY Testing Challenges
and Opportunities:
The Need For a Smart
Testing Approach

2. © 2019 MIPI Alliance, Inc. 3
PHY Testing – Ideal Scenario
Victor Sanchez-Rico - BitifEye Digital Test Solutions GmbH
Low Cost
Testing
Fast Testing
Speeds
Comparable
Results
Choice of Test Systems
InterOp
Test Houses

3. © 2019 MIPI Alliance, Inc. 4
Common RX Test Approaches: Loopback
• Pattern Generator in BERT sends continuous test pattern to DUT
• DUT processes the test data and sends it back to the BERT
Analyzer
• Pattern compared, Bit Error Rate calculated
Victor Sanchez-Rico - BitifEye Digital Test Solutions GmbH
BERT
Test Pattern
Generator
Test Pattern
Analyzer
DUT
RX
TX
=?

4. © 2019 MIPI Alliance, Inc. 5
Common RX Test Approaches: Loopback
• Challenges:
– DUT comes out of test mode whenever the test pattern generator is
restarted
• Manual intervention of test operator is required (time consuming) or
• Automation scripts and side-band connection are required (customization)
– Can’t test real world data (Burst)
– Some tests can’t be done easily, e.g. Squelch detection in MIPI M-
PHY®
Victor Sanchez-Rico - BitifEye Digital Test Solutions GmbH

5. © 2019 MIPI Alliance, Inc. 6
Common RX Test Approaches: Loopback
Victor Sanchez-Rico - BitifEye Digital Test Solutions GmbH
Low Testing
Costs
Fast Testing
Speeds
Comparable
Results
Choice of Test Systems
InterOp
Test Houses

6. © 2019 MIPI Alliance, Inc. 7
Common RX Test Approaches: Side-band
• Proprietary access to built in Error Counters
• Pattern Generator in Test Equipment sends test pattern to DUT
• DUT processes the test data and counts errors
• Additional connection to the DUT to grab counters through customer-specific
equipment
Victor Sanchez-Rico - BitifEye Digital Test Solutions GmbH
BERT
Test Pattern
Generator DUTRX
Side-band
deviceComputer

7. © 2019 MIPI Alliance, Inc. 8
Common RX Test Approaches: Side-band
Victor Sanchez-Rico - BitifEye Digital Test Solutions GmbH
Low Testing
Costs
Fast Testing
Speeds
Comparable
Results
Choice of Test Systems
InterOp
Test Houses

8. © 2019 MIPI Alliance, Inc. 9
Common RX Test Approaches: Visual Test
Victor Sanchez-Rico - BitifEye Digital Test Solutions GmbH
Low Testing
Costs
Fast Testing
Speeds
Comparable
Results
Choice of Test Systems
InterOp
Test Houses

9. © 2019 MIPI Alliance, Inc. 10
Solution: PHY Test Mode
• Functionality that allows to configure the DUT for test
exclusively with in-band control commands
• Simplified link startup for simplicity
• Bit and error counters also retrieved with Test Equipment via
in-band commands
• Preferably implemented in the PHY Layer
• Optional: master device can configure test mode for slave(s),
and run some tests w/o need for test equipment.
Victor Sanchez-Rico - BitifEye Digital Test Solutions GmbH

10. © 2019 MIPI Alliance, Inc. 11
Solution: PHY Test Mode
Victor Sanchez-Rico - BitifEye Digital Test Solutions GmbH
Low Cost
Testing
Fast Testing
Speeds
Comparable
Results
Choice of Test Systems
InterOp
Test Houses

11. © 2019 MIPI Alliance, Inc. 12
PHY Test Mode Example: MIPI M-PHY® MIPI UniPro® RX Test
• Use Case
– DUT Data0 RX is connected to switch that can alternate
between test pattern generator and protocol generator
– DUT Data1-3 RX connected directly to test pattern
generator
– DUT Data 0 TX connected to protocol analyzer
– DUT RST_n also controlled to alternate test modes
Victor Sanchez-Rico - BitifEye Digital Test Solutions GmbH
• Test Flow
– Automation connects protocol generator to DUT
– Hardware Reset sent to RST_n of DUT
– Protocol generator sends link configuration pattern to
DUT
– Automation connects test pattern generator to DUT
– Test pattern generator sends test pattern to DUT, interleaving Frame and Error counter requests
– DUT responds, protocol analyzer captures response and test automation decodes it
– Test goes on until DUT reports errors or target BER is achieved
DUT
RX0
RX1
RX2
RX3 TX3
TX1
TX2
Protocol
Analayzer
(PWM)
Protocol
Generator
(PWM)
Test Pattern
Generator
(High Speed)
TX0

12. © 2019 MIPI Alliance, Inc. 13
PHY Test Mode Example: MIPI M-PHY®" MIPI UniPro® TX Test
Victor Sanchez-Rico - BitifEye Digital Test Solutions GmbH
• Use Case
– DUT Data0 RX is connected protocol generator
– DUT TX Lane under test is connected to
oscilloscope
– DUT RST_n also controlled to alternate test
modes
• Test Flow
– Protocol generator sends Hardware Reset to
DUT
– Protocol generator sends link configuration
pattern to DUT
– Automation controls oscilloscope TX Test
software to run selected tests
Protocol
Generator
(PWM)
DUT
RX0 TX0
RX1
RX2
RX3 TX3
TX1
TX2
DSO

13. © 2019 MIPI Alliance, Inc. 14
Outlook and suggestion: A-PHY
• Unlike MIPI M-PHY®, both bus
directions are transmitted
simultaneously on the same wire
– Only one direction for High
Speed data, but control data is
full duplex, on the same wire
– No fixture is available that can
be used to combine and split
the data
Victor Sanchez-Rico - BitifEye Digital Test Solutions GmbH
RX
DUT
RX
TX
Signal Analyzer
/ Oscilloscope
Signal
Generator

14. © 2019 MIPI Alliance, Inc. 15
Outlook and suggestion: A-PHY
• A-PHY uses a very long channel. Embedding it (software
simulation) seems like the sensible choice but it can have a
very big impact on test pattern generation time
Victor Sanchez-Rico - BitifEye Digital Test Solutions GmbH

15. © 2019 MIPI Alliance, Inc. 16
About BitifEye
• Located in Boeblingen, Germany
• Solutions Partner of Keysight Technologies, system integrator
– integration of high-performance test instruments: bit-error ratio testers, oscilloscopes, network analyzers…
– complementary products - software, accessories, instruments - and services
• Experts in wireline digital high-speed interconnect test, e.g. HDMI, USB, MIPI
– focus on physical layer (PHY) tests - compliance tests and product characterization
– inventor of PHY test automation for gigabit receivers/sinks, market leader since 2005
– provider of complementary hardware, software and services
Victor Sanchez-Rico - BitifEye Digital Test Solutions GmbH

16. © 2019 MIPI Alliance, Inc.
Broadly used by
small / midsize
companies.
Experts on-
site
Unique instrument pool
Product characterization,
margin test, debugging
PHY Pre-compliance tests,
e.g. MIPI, HDMI, USB,
SATA,
Official MIPI® Test Lab
Ø Participant (with Keysight) in various InterOps,
Plug fests, Certification workshops (e.g. UFS)
throughout the years
Ø Partner of various test labs all around the world
(e.g. Allion, Eurofins, Simplay Labs, GRL, IST ...)
About BitifEye
Victor Sanchez-Rico - BitifEye Digital Test Solutions GmbH