1. Leonardo da Vinci ALLEGRO © J. M. Martins Ferreira - University of Porto (FEUP / DEEC)1 Non-BS cluster testing by PRPG / SA J. M. Martins Ferreira FEUP / DEEC - Rua Dr. Roberto Frias 4200-537 Porto - PORTUGAL Tel. 351 225 081 748 / Fax: 351 225 081 443 (jmf@fe.up.pt / http://www.fe.up.pt/~jmf)

2. Leonardo da Vinci ALLEGRO © J. M. Martins Ferreira - University of Porto (FEUP / DEEC)2 Objectives To introduce the concepts of pseudo- random pattern generation (PRPG) and signature analysis (SA) To perform an exhaustive test of a cluster of non-BS components using a PRPG / SA approach

3. Leonardo da Vinci ALLEGRO © J. M. Martins Ferreira - University of Porto (FEUP / DEEC)3 Outline The cluster to be tested Information required Alternative routes to the solution Test program generation Experiment

4. Leonardo da Vinci ALLEGRO © J. M. Martins Ferreira - University of Porto (FEUP / DEEC)4 The demonstration board

5. Leonardo da Vinci ALLEGRO © J. M. Martins Ferreira - University of Porto (FEUP / DEEC)5 The IC1+IC2 non-BS cluster To be used in PRPG mode To be used in SA mode

6. Leonardo da Vinci ALLEGRO © J. M. Martins Ferreira - University of Porto (FEUP / DEEC)6 What do we have to know? How many test vectors are required to guarantee that all 16 combinations are applied to the cluster inputs? (assuming that the BST octal on the left works in 16- bit PRPG mode) What is the correct signature at the end? (assuming that the BST octal on the right works in 16-bit SA mode)

7. Leonardo da Vinci ALLEGRO © J. M. Martins Ferreira - University of Porto (FEUP / DEEC)7 Pseudo-random pattern generation How to determine the required number of TCK cycles? –Using a general logic simulation tool: develop a simulation model for the PRPG structure –Using Scan Educator: set up the required PRPG mode and apply TCK cycles until all 16 combinations are identified –In practice: carry out a real test run and analyse the PRPG outputs involved

8. Leonardo da Vinci ALLEGRO © J. M. Martins Ferreira - University of Porto (FEUP / DEEC)8 Signature analysis How to determine the correct signature at the end? –Using a general logic simulation tool: develop simulation models for the three blocks (PRPG, non-BS cluster, SA) –In practice: carry out a real test run using a fault-free circuit and read the resulting signature

9. Leonardo da Vinci ALLEGRO © J. M. Martins Ferreira - University of Porto (FEUP / DEEC)9 The number of TCK cycles required for PRPG Select “scan control mode testing – single device – on your own” Set up the required PRPG mode Apply TCK cycles until all sixteen combinations are identified

10. Leonardo da Vinci ALLEGRO © J. M. Martins Ferreira - University of Porto (FEUP / DEEC)10 Determining the correct signature Using the Bitstream Shifter application, set up the required operating mode for the two octals (16-bit PRPG / SA) Bring the octals to Run Test / Idle and apply the required number of TCK cyles Read the correct signature in the RX field

11. Leonardo da Vinci ALLEGRO © J. M. Martins Ferreira - University of Porto (FEUP / DEEC)11 Test procedure BOUNDARY READ opcode  IR Shift in the initial seed values  DR (BS) TEST DATA REGISTER SCAN opcode  IR Set up the required operating mode (TDR: 01 for 16-bit PRPG and 10 for 16-bit SA) BOUNDARY RUN opcode  IR Apply the required number of TCK cycles in Run Test / Idle and check the signature

12. Leonardo da Vinci ALLEGRO © J. M. Martins Ferreira - University of Porto (FEUP / DEEC)12 Conclusion Difference between PRPG / SA and deterministic test vector generation procedures Difference between the required number of TCK cycles (test speed) –Exhaustive testing via PRPG / SA –Shifting in / out each test vector and response individually