ADLINK PCIe-7350 - Manual (Page 51)

Function Block and Operation Theory 41
3.7.4 DI DMA in Handshaking Mode
For the DI pattern acquisition operation in handshaking mode,
PCIe-7350 card can acquire input data from external devices by
handshaking data transfer through DI-REQ input signal and DI-
ACK output signal of AFI interface. The operation sequences are
listed as follows:
Step1: Configuration

Define DI port configuration (32/24/16/8-bits data width)

Define DI logic level configuration (3.3/2.5/1.8V)

Define DI-REQ and DI-ACK signal (AFI0 ~ AFI7)

For example: if configure AFI3 as DI-REQ and AFI4 as
DI-ACK, and then you must connect the handshaking
signal (DI-REQ and DI-ACK) of external device to the
AFI3 and AFI4.

Define DI starting mode configuration (NoWait or WaitTRIG)

If choose WaitTRIG, you can define start trigger source
to be software trigger or external trigger (DI-Start or DI-
TRIG) from AFI0 ~ AFI7.
 Define DI data count
Step2: Execute DI DMA Read Command (handshaking mode)

After DI data is ready on device side, the peripheral device
strobe data into the PCIe-7350 by asserting a DI-REQ sig-
nal. (action_1)

The DI-REQ signal caused the PCIe-7350 to latch DI data
and store it into DI FIFO. (action_2)
 The PCIe-7350 asserts a DI-ACK signal when it is ready for
another input. (action_3)

The action_1 to action_3 is repeated in handshaking
mode.

The DI data in the DI FIFO will be transferred into system
memory directly and automatically by bus mastering DMA.