1149 6 Crossover issue Ted Eaton coerced by

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1149. 6 Cross-over issue Ted Eaton coerced by the late Bill Eklow 9/15/2010 Paper

1149. 6 Cross-over issue Ted Eaton coerced by the late Bill Eklow 9/15/2010 Paper #15 © 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential 1

1149. 6 test Receivers Differential? § The standard tells us 6. 2. 1. 1

1149. 6 test Receivers Differential? § The standard tells us 6. 2. 1. 1 Rules a) All AC pins (see 4. 1) that receive input data, whether they are single-ended or one leg of a differential pair, shall have exactly one test receiver function monitoring the mission pin signal. § BSDL tells us : List all DIFF + pins in the AIO_PIN_BEHAVIOR Infer. 6 behavior on – pins using PORT_GROUPING § The ATPG tools don’t bother to care A DIFF is a DIFF Paper #15 © 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential 2

ATPG Does this great Paper #15 © 2008 Cisco Systems, Inc. All rights reserved.

ATPG Does this great Paper #15 © 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential 3

1149. 6 test Receivers Differential? § Board Layout rules tell us sometimes it is

1149. 6 test Receivers Differential? § Board Layout rules tell us sometimes it is better to route + to – § ASIC design says ok… connect the pins as you need and we will invert + and – in functional mode and. 6 is single ended so who cares. § The ATPG tools don’t bother to care “A DIFF is a DIFF” Paper #15 © 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential 4

ATPG Does this Great… WAIT!!!! A DIFF is NOT a DIFF Paper #15 ©

ATPG Does this Great… WAIT!!!! A DIFF is NOT a DIFF Paper #15 © 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential 5

Paper #15 © 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential 6

Paper #15 © 2008 Cisco Systems, Inc. All rights reserved. Cisco Confidential 6