National Instruments NI 653 Series, User Manual

Page: 92 / 151

Chapter 3 Timing Diagrams
NI 653X User Manual 3-36 ni.com
Figure 3-37. Long-Pulse Output Timing Diagram
Note With REQ-edge latching disabled (default), output data valid is held t
rdo
ns after the
REQ edge with REQ-edge latching enabled that data is 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
1
—
t
r*do
REQ inactive to new output data
(with REQ-edge latching)
0 50
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
t
aa*
(min.) = 125 + programmable delay
REQ
Output Data Valid
(REQ-edge
Latching)
Output Data Valid
(REQ-edge
Latching Disabled)
t
r*r
t
r*do
t
doa
t
ar
t
aa*
t
rr*
ACK
t
rdo
ACK and REQ are shown as active high.