Extended Boundary Scan Test Using Hybrid Test Vectors Presented - - PowerPoint PPT Presentation

Slide 1 EBTW 2005, Tallinn, Estonia

• Extended Boundary Scan Test

Using Hybrid Test Vectors

Presented by: Jan Heiber GOEPEL electronic GmbH

Slide 2 EBTW 2005, Tallinn, Estonia

• Overview

Boundary Scan net test coverage Reduced testability of edge connector nets Extended Boundary Scan test coverage without HYSCANTM and its limits Extended Boundary Scan test coverage with HYSCANTM HYSCANTM in software

Slide 3 EBTW 2005, Tallinn, Estonia

• Boundary Scan Test Strategy

C O I C O I C O I

Slide 4 EBTW 2005, Tallinn, Estonia

• Reduced Testability

!

DISPLAY

(LED / LCD)

IEEE1149.1 POWER RAM 1...4 FLASH 1...2 A D C A D C A D C

PLD

TDI TDO

C (FLASH) CLK A D C (RAM)

TDI TDO

µP

CLK RS232

CLUSTER UUT

Buffer Board revision?

Slide 5 EBTW 2005, Tallinn, Estonia

• Extended Boundary Scan Test
• C

O I C O I C O I C O I C O I C O I

Slide 6 EBTW 2005, Tallinn, Estonia

• Extended Boundary Scan Test

DISPLAY

(LED / LCD)

IEEE1149.1 POWER RAM 1...4 FLASH 1...2 A D C A D C A D C

PLD

TDI TDO

C (FLASH) CLK A D C (RAM)

TDI TDO

µP

CLK RS232 Board revision?

CLUSTER UUT

Buffer

BScan BScan

RS232 IEEE1149.1

BScan

TDI TDI TDI TDO TDO TDO

Customer specific adapter

Slide 7 EBTW 2005, Tallinn, Estonia

• Extended Boundary Scan Test

Advantages

Higher coverage than with stand alone UUT Better diagnostics

Limits

Speed issue with serial test extension Single adapter type during test development and execution Adjustments require re-generation of all automatic test vectors Statistic discrepancies in analysis and reports

Slide 8 EBTW 2005, Tallinn, Estonia

• Why Discrepancies?

"#!$ %%& & &! $ '() )*+ &!! $ )*,- * %%&.& &! $ /01 &!! $ +(

2

!$03

Slide 9 EBTW 2005, Tallinn, Estonia

• Extended Boundary Scan Statistics

"#!$ %%& %%& .& $ &! $ '(),'334- /)0,'334- ! $ ''(,1'504- +*/,6'504- ,-$ 7! $ '',''514- )',(514- $ 1/,16514- +0+,6'5(4- 8 $ *,*5/4- *,'514-

Slide 10 EBTW 2005, Tallinn, Estonia

• HYSCANTM – Hybrid Scan

Synchronized serial and parallel test vectors Independencies between UUT and test accessories

Slide 11 EBTW 2005, Tallinn, Estonia

• Extended Boundary Scan Statistics

"#!$ %%& %%& .&%%&.9:78&2 $ &! $'(),'334- /)0,'334- '(),'334- ! $''(,1'504- +*/,6'504- ''(,1'504- ,-$ 7! $'',''514- )',(514- )',))4- $ 1/,16514- +0+,6'5(4- //,/*5/4- 8 $ *,*5/4- *,'514- *,*5/4-

Slide 12 EBTW 2005, Tallinn, Estonia

• HYSCANTM – Test Channel

Requirement: Bi-directional pin behavior Enable / disable capabilities Software controlled test channels Nice to have: Wide voltage range High current supply Test channels may even be Boundary Scan pins

Slide 13 EBTW 2005, Tallinn, Estonia

• HYSCANTM – Principle

:&"2778&2 & 2 &!,78-

• ;#

7<5 <= & 2 & ! ><= ><= <= 7!&!#

Support of different types of pin electronic during the whole product life cycle due to exchangeable driver software and test channel mapper

Slide 14 EBTW 2005, Tallinn, Estonia

• HYSCANTM – Test Generation

Step1: Define the virtual adapter Step2: Add UUT access points Step3: Generate test(s) with(out) test channels Step4: Replace virtual test channels by the real adapter (wiring list)

PC 1

Tester Configuration X

PC 2

Tester Configuration Y

Project A

Tester Configuration X Tester Configuration Y

Slide 15 EBTW 2005, Tallinn, Estonia

• Definition Of The Virtual Adapter

Step 1 Define Virtual Test Channels Simplify interface for test enhancement via edge connectors and test points

Slide 16 EBTW 2005, Tallinn, Estonia

• UUT Access Points

Step 2 Add UUT Access Points

,'-><< ,0-,- ,)-><< ,+- ,/-&

Slide 17 EBTW 2005, Tallinn, Estonia

• Test Generation

Step 3 Test Generation with/without test channels

LDI U2, Sample; LDI U1, Sample; LDI U_DIO, Sample; IRSHIFT; (* Stuck-At-Low Test (will set all lines at high). *) (* 5 test steps. *)

• - Disable pins

DL (U2:IO34/C, IO33/C, IO31/C, IO28/C, IO27/C, IO25/C); DL ( IO11/C, IO10/C, IO8/C, IO6/C, IO5/C, IO3/C); ... DL (U_DIO:TC[10]/C, TC[11]/C);

Slide 18 EBTW 2005, Tallinn, Estonia

• Wiring List

Step 4 Wiring list = replacement of virtual test channels by real test channels

? %%& >@@<

!< =

Slide 19 EBTW 2005, Tallinn, Estonia

• Conclusions

Exchangeability between different adapter types More accurate results and statistics while achieving same coverage Test coverage estimations (with and without adapting connector nets) HYSCANTM keeps UUT and adaptor separated Boundary Scan tests independent from the test adapter Independency between test program developer and executor Basically for all adapter types using bi-directional pin electronic Controlling different adapter types via DLL

Slide 20 EBTW 2005, Tallinn, Estonia

• End

Many thanks for your attention!