National Instruments 653X - Manual (Page 70)

Chapter 3 Timing Diagrams
© National Instruments Corporation 3-19 653X User Manual
Figure 3-15. Level ACK Input State Machine
Wait
For
Space
Wait
For
REQ
Programmable
Delay
Programmable
Delay
Wait
For
REQ
When REQ
Asserted
Clear ACK
When 6533 Device has space
for data, input data.*
When REQ
Unasserted
Initial State: ACK Cleared
Send
ACK
* With REQ-edge latching enabled, the data input
is from the last active-going REQ edge.