SN74LVTH18502A-EP Datasheet, PDF (18/42 Pages) Texas Instruments – 3.3-V ABT SCAN TEST DEVICES WITH 18-BIT UNIVERSAL BUS TRANSCEIVERS

SN74LVTH18502AĆEP, SN74LVTH182502AĆEP
3.3ĆV ABT SCAN TEST DEVICES
WITH 18ĆBIT UNIVERSAL BUS TRANSCEIVERS
SCAS744A − DECEMBER 2003 − REVISED JUNE 2004
parallel-signature analysis (PSA)
Data appearing at the selected device input-mode I/O pins is compressed into a 36-bit parallel signature in the
shift-register elements of the selected BSCs on each rising edge of TCK. Data in the shadow latches of the
selected output-mode BSCs remains constant and is applied to the associated device I/O pins. Figures 7 and 8
show the 36-bit linear-feedback shift-register algorithms through which the signature is generated. An initial
seed value should be scanned into the BSR before performing this operation.
2A9-I/O 2A8-I/O 2A7-I/O 2A6-I/O 2A5-I/O 2A4-I/O 2A3-I/O 2A2-I/O 2A1-I/O
1A9-I/O 1A8-I/O 1A7-I/O 1A6-I/O 1A5-I/O 1A4-I/O 1A3-I/O 1A2-I/O 1A1-I/O
2B9-I/O 2B8-I/O 2B7-I/O 2B6-I/O 2B5-I/O 2B4-I/O 2B3-I/O 2B2-I/O 2B1-I/O
=
=
1B9-I/O 1B8-I/O 1B7-I/O 1B6-I/O 1B5-I/O 1B4-I/O 1B3-I/O 1B2-I/O 1B1-I/O
Figure 7. 36-Bit PSA Configuration (1OEAB = 2OEAB = 0, 1OEBA = 2OEBA = 1)
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