National Instruments DIO 6533 - Manual (Page 74)

Chapter 5 Signal Timing
© National Instruments Corporation 5-15 DIO 6533 User Manual
Figure 5-12 shows an input transfer in leading-edge mode.
Figure 5-12. Leading-Edge Mode Input
Wait
For
Space
Wait
For
REQ
Programmable
Delay
Programmable
Delay
Wait
For
REQ
When REQ
Asserted
When 6533 Device
Has Space For Data,
Input Data*
Clear
ACK
Pulse
When REQ
Unasserted
Initial State
ACK Cleared
Send
ACK
Pulse
* With REQ-edge latching enabled, the data read
is from the last active-going REQ edge.