National Instruments 653X Switch User Manual


 
Chapter 3 Timing Diagrams
653X User Manual 3-34 ni.com
Figure 3-31. Leading Edge Output Timing Diagram
Note
With REQ edge latching disabled (default), output data valid will hold t
rdo
ns after
the REQ edge occurs. With REQ edge latching enabled, that data will be held for at most
t
rdo
ns after the REQ edge deasserts.
Parameter Description Minimum Maximum
Input Parameters
t
rr*
REQ pulse width 75
t
r*r
REQ inactive duration 75
t
ar
ACK to next REQ 0
Output Parameters
t
aa*
ACK pulse width 125
t
r*a*
REQ inactive to ACK inactive 150
t
r*do
REQ inactive to new output data
(with REQ-edge latching)
050
t
rdo
REQ to new output data
(with REQ-edge latching disabled)
0—
t
doa
Output data valid to ACK
(with REQ-edge latching disabled)
25
1
1
t
doa
(min.) = 25 + programmable delay
REQ
Output Data Valid
(REQ-edge
latching)
Output Data Valid
(REQ-edge
latching disabled)
t
r*r
t
r*a*
t
r*do
t
doa
t
ar
t
aa*
t
rr*
ACK
t
rdo
ACK and REQ are shown as active high