80KSBR200 Datasheet, PDF (138/172 Pages) Integrated Device Technology – sRIO SERIAL BUFFER FLOW-CONTROL DEVICE

IDT 80KSBR200
Notes
Advanced Datasheet*
The output enable cells are also output cells. The simplified logic appears in the figure below.
Output Enable
From Core
EXTEST
To next cell
To output enable
Data from previous cell
DQ
DQ
shift_dr
clock_dr
update_dr
Figure 45 Diagram of Output Enable Cell
The bidirectional cells are composed of only two boundary scan cells. They contain one output enable cell and one
capture cell, which contains only one register. The input to this single register is selected via a mux that is selected by the
output enable cell when EXTEST is disabled. When the Output Enable Cell is driving a high out to the pad (which enables
the pad for output) and EXTEST is disabled, the Capture Cell will be configured to capture output data from the core to the
pad.
However, in the case where the Output Enable Cell is low (signifying a tri-state condition at the pad) or EXTEST is
enabled, the Capture Cell will capture input data from the pad to the core. The configuration is shown graphically in the
figure below.
Output enable from core
EXTEST
From previous cell
Output Enable Cell
Output from core
Capture Cell
I/O
Input to core
Pin
To next cell
Figure 46 Diagram of Bidirectional Cell
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March 19, 2007
„2005 Integrated Device Technology, Inc. All rights reserved. Advanced Datasheet for informational purposes only. Product specifications subject to change without notice.NOT AN OFFER FOR SALE The information presented herein is subject to a
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