ADLINK PCIe-7200 - Manual (Page 46)

Operation Theory 37
3. I_REQ & I_ACK Handshaking
Note: I_REQ must be asserted until I_ACK asserts, I_ACK will be
asserted until I_REQ de-asserts.
4. O_REQ as output data strobe
5. O_REQ & O_ACK Handshaking
Note: O_ACK must be de-asserted before O_REQ asserts,
O_ACK can be asserted any time after O_REQ asserts,
O_REQ will be reasserted after O_ACK is asserted.
t1

0ns t5

60ns t3

2 PCI CLK Cycle
t2

0ns t4

1 PCI CLK Cycle
ts

19ns th

2 PCI CLK Cycles Tcyc

500ns
valid data D10~DI31 valid data
t1
t2
t5
t4 t3
IN I_REQ
IN I_ACK