Cypress CY7C1464AV25 manual TAP Timing, Parameter Description Min Max Unit Clock, Output Times

CY7C1460AV25

CY7C1462AV25

CY7C1464AV25

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

12

Test Clock

(TCK)tTH

tTMSS tTMSH

Test Mode Select (TMS)

tTDIS tTDIH

Test Data-In (TDI)

3 4 5 6

tTL tCYC

tTDOV

tTDOX

	Test Data-Out
	(TDO)
	DON’T CARE	UNDEFINED
TAP AC Switching Characteristics Over the Operating Range[9, 10]
Parameter	Description	Min.	Max.	Unit
Clock
tTCYC	TCK Clock Cycle Time	50		ns
tTF	TCK Clock Frequency		20	MHz
tTH	TCK Clock HIGH time	20		ns
tTL	TCK Clock LOW time	20		ns
Output Times
tTDOV	TCK Clock LOW to TDO Valid		10	ns
tTDOX	TCK Clock LOW to TDO Invalid	0		ns
Set-up Times
tTMSS	TMS Set-up to TCK Clock Rise	5		ns
tTDIS	TDI Set-up to TCK Clock Rise	5		ns
tCS	Capture Set-up to TCK Rise	5		ns
Hold Times
tTMSH	TMS Hold after TCK Clock Rise	5		ns
tTDIH	TDI Hold after Clock Rise	5		ns
tCH	Capture Hold after Clock Rise	5		ns

Notes:

9.tCS and tCH 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. tR/tF = 1 ns.

Document #: 38-05354 Rev. *D Page 12 of 27

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