National Instruments 653X Manuale Utente

Pagina di 147
Chapter 3
Timing Diagrams
3-22
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Figure 3-18.  Level ACK Output State Machine
Wait
For
Data
Wait
For
REQ
Programmable
Delay
Programmable
Delay
Wait
For
REQ
When REQ
Asserted
Clear ACK
When 6533 Device has data 
to output, output data.*
When REQ
Unasserted
Initial State: ACK Cleared
Send
ACK
* With REQ-edge latching enabled, the data output is
delayed until the next inactive-going REQ edge.