Tap timing tap ac switching characteristics – Cypress CY7C1381F User Manual
Page 13
CY7C1381D, CY7C1381F
CY7C1383D, CY7C1383F
Document #: 38-05544 Rev. *F
Page 13 of 29
(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
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
Setup Times
t
TMSS
TMS Setup to TCK Clock Rise
5
ns
t
TDIS
TDI Setup to TCK Clock Rise
5
ns
t
CS
Capture Setup 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
t
TL
Test Clock
(TCK)
1
2
3
4
5
6
Test Mode Select
(TMS)
tTH
Test Data-Out
(TDO)
tCYC
Test Data-In
(TDI)
tTMSH
tTMSS
tTDIH
tTDIS
tTDOX
tTDOV
DON’T CARE
UNDEFINED
Notes:
10. t
CS
and t
CH
refer to the setup and hold time requirements of latching data from the boundary scan register.
11. Test conditions are specified using the load in TAP AC test conditions. t
R
/t
F
= 1 ns.