National Instruments 653 Series User Manual page 86

ACK
REQ
Output Data Valid
(REQ-edge
Latching Disabled)
Output Data Valid
(REQ-edge
Latching)
Parameter
Input Parameters
t
REQ pulse width
rr*
t
REQ inactive duration
r*r
t
ACK to next REQ
ar
Output Parameters
t
ACK pulse width
aa*
t
REQ inactive to ACK inactive
r*a*
t
REQ inactive to new output data
r*do
(with REQ-edge latching)
t
REQ to new output data
rdo
(with REQ-edge latching disabled)
t
Output data valid to ACK
doa
(with REQ-edge latching disabled)
1
t (min.) = 25 + programmable delay
doa
With REQ-edge latching disabled (default), output data valid is held t
Note
REQ edge occurs. With REQ-edge latching enabled, that data is held for at most t
after the REQ edge deasserts.
© National Instruments Corporation
t
aa*
t
r*a*
t
ar
t
r*r
t
doa
Description
Figure 3-31. Leading-Edge Output Timing Diagram
3-31
Chapter 3
t
rr*
t
rdo
t
r*do
ACK and REQ are shown as active high.
Minimum
75
75
0
150
150
0
0
1
25
Timing Diagrams
Maximum
—
—
—
—
—
50
—
—
ns after the
rdo
ns
rdo
NI 653X User Manual