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IDT JTAG Boundary Scan
PES24T3G2 User Manual
9 - 5
February 22, 2012
Notes
Figure 9.4 Diagram of Output Cell
The output enable cells are also output cells. The simplified logic is shown in Figure 9.5.
Figure 9.5 Diagram of Bidirectional 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 Figure 9.5.
Data from Core
Data from Previous Cell
shift_dr
To Next Cell
To Output Pad
clock_dr
update_dr
MU
X
D
Q
D
Q
EXTEST
MUX
D
Q
D
Q
Data from core
shift_dr
MU
X
D
Q
D
Q
clock_dr
shift_dr
update_dr
MUX
MU
X
MU
X
OEN to pad
I/O pin
Output enable from core
EXTEST
EXTEST
Data from previous cell
To next cell
Содержание 89HPES24T3G2ZBAL
Страница 8: ...IDT PES24T3G2 User Manual 6 February 22 2012 Notes...
Страница 12: ...IDT Table of Contents PES24T3G2 User Manual iv February 22 2012 Notes...
Страница 14: ...IDT List of Tables PES24T3G2 User Manual vi February 22 2012 Notes...
Страница 16: ...IDT List of Figures PES24T3G2 User Manual viii February 22 2012 Notes...
Страница 20: ...IDT Register List PES24T3G2 User Manual xii February 22 2012 Notes...
Страница 32: ...IDT PES24T3G2 Device Overview PES24T3G2 User Manual 1 12 February 22 2012 Notes...
Страница 72: ...IDT SMBus Interfaces PES24T3G2 User Manual 5 20 February 22 2012 Notes...
Страница 76: ...IDT Power Management PES24T3G2 User Manual 6 4 February 22 2012 Notes...
Страница 156: ...IDT Configuration Registers PES24T3G2 User Manual 8 74 February 22 2012 Notes...