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1149.6 Cross-over issue. Ted Eaton coerced by the late Bill Eklow 9/15/2010. 1149.6 test Receivers Differential?. The standard tells us 6.2.1.1 Rules
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1149.6 Cross-over issue Ted Eaton coerced by the late Bill Eklow 9/15/2010
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 is a DIFF
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 is a DIFF”
ATPG Does this Great… WAIT!!!! A DIFF is NOT a DIFF