National Instruments 653X - Manual (Page 57)

Chapter 3 Timing Diagrams
653X User Manual 3-6 ni.com
Figure 3-3. Burst Transfer Example (Input)
Figure 3-4. Burst Transfer Example (Output)
Note Since data is transferred only when both the 653X device and the peripheral device
are ready (and thus ACK and REQ are asserted), it is not reasonable to expect data to arrive
at consistent intervals. If consistent intervals are an important criteria for your application,
use pattern I/O.
PCLK
ACK
Data In
Valid
REQ
D5 D1 D2 D3 D4
= data transfer occurs
PCLK
ACK
REQ
Data Out
Valid
D1 D2 D3 D4 D5
= data transfer occurs