Filter
Top Products
CY7C1460AV33
CY7C1462AV33
CY7C1464AV33
Document #: 38-05353 Rev. *D Page 12 of 27
When this scan cell, called the “extest output bus tri-state,” is
latched into the preload register during the “Update-DR” state
in the TAP controller, it will directly control the state of the
output (Q-bus) pins, when the EXTEST is entered as the
current instruction. When HIGH, it will enable the output
buffers to drive the output bus. When LOW, this bit will place
the output bus into a High-Z condition.
This bit can be set by entering the SAMPLE/PRELOAD or
EXTEST command, and then shifting the desired bit into that
cell, during the “Shift-DR” state. During “Update-DR,” the value
loaded into that shift-register cell will latch into the preload
register. When the EXTEST instruction is entered, this bit will
directly control the output Q-bus pins. Note that this bit is
preset HIGH to enable the output when the device is
powered-up, and also when the TAP controller is in the
“Test-Logic-Reset” state.
Reserved
These instructions are not implemented but are reserved for
future use. Do not use these instructions.
TAP Timing
TAP AC Switching Characteristics
Over the Operating Range
[9, 10]
Parameter Description Min. Max. Unit
Clock
t
TCYC
TCK Clock Cycle Time 50 ns
t
TF
TCK Clock Frequency 20 MHz
t
TH
TCK Clock HIGH time 20 ns
t
TL
TCK Clock LOW time 20 ns
Output Times
t
TDOV
TCK Clock LOW to TDO Valid 10 ns
t
TDOX
TCK Clock LOW to TDO Invalid 0 ns
Set-up Times
t
TMSS
TMS Set-up to TCK Clock Rise 5 ns
t
TDIS
TDI Set-up to TCK Clock Rise 5 ns
t
CS
Capture Set-up to TCK Rise 5 ns
Hold Times
t
TMSH
TMS Hold after TCK Clock Rise 5 ns
t
TDIH
TDI Hold after Clock Rise 5 ns
t
CH
Capture Hold after Clock Rise 5 ns
Notes:
9. t
CS
and t
CH
refer to the set-up and hold time requirements of latching data from the boundary scan register.
10.Test conditions are specified using the load in TAP AC test Conditions. t
R
/t
F
= 1 ns.
t
TL
Test Clock
(TCK)
123456
T
est Mode Select
(TMS)
t
TH
Test Data-Out
(TDO)
t
CYC
Test Data-In
(TDI)
t
TMSH
t
TMSS
t
TDIH
t
TDIS
t
TDOX
t
TDOV
DON’T CARE UNDEFINED
[+] Feedback