ADLINK PCIe-7200 - Manual (Page 40)

Operation Theory 31
4 Operation Theory
In the 7200 series, there are four data transfer modes can be used
for digital I/O access and control, these modes are:
1. Direct Program Control: the digital inputs and outputs
can be read/written and controlled by its corresponding I/
O port address directly.
2. Internal Timer Pacer Mode: the digital input and output
operations are paced by an internal timer pacer and are
transferred by bus mastering DMA.
3. External Clock Mode: the digital input operation is
clocked by external I_REQ strobe and transferred by bus
mastering DMA.
4. Handshaking: through REQ and ACK signals, the digital
I/O can have simple handshaking data transfers.
4.1 Direct Program Control
Digital I/O operations can be controlled by I/O port BASE+10 for
digital input and BASE+14 for digital output.
The I/O port address BASE is assigned by system BIOS, please
refer to Section 5 for a more detailed description.
The digital OUT operation is:
outport (BASE+14, 0xAAAAAAAA) // (A : 0 to F)
The digital IN operation is:
value = inport (BASE+10) // The input status
is save in the // value variable