ADLINK PCIe-7350 - Manual (Page 54)

44 Function Block and Operation Theory
3.7.5 DO DMA in Handshaking Mode
For the DO pattern generation operation in handshaking mode,
PCIe-7350 card can generate output data to external devices by
handshaking data transfer through DO-REQ output signal and
DO-ACK input signal of AFI interface. The operation sequences
are listed as follows:
Step1: Configuration

Define DO port configuration (32/24/16/8-bits data width)

Define DO logic level configuration (3.3/2.5/1.8V)

Define DO-REQ and DO-ACK signal (AFI0 ~ AFI7)

For example: if configure AFI3 as DO-REQ and AFI4 as
DO-ACK, and then you must connect the handshaking
signal (DO-REQ and DO-ACK) of external device to the
AFI3 and AFI4.

Define DO starting mode configuration (NoWait or Wait-
TRIG)

If choose WaitTRIG, you can define start trigger source
to be software trigger or external trigger (DO-Start or
DO-TRIG) from AFI0 ~ AFI7.

Define DO write count
Step2: Execute DO DMA Write Command (handshaking mode)

The DO data saved in the system memory will be trans-
ferred to DO FIFO directly and automatically by bus master-
ing DMA.
 After DO data are ready, DO-REQ signal is generated and
DO data are sent to the external device. (action_1)

After DO-ACK signal from external device is gotten
(action_2)

The action_1 to action_2 is repeated in handshaking
mode.