Appreciate any specific help or general guidance to my question below:

Suppose I have two FPGAs: FPGA_master and FPGA_slave.

On FPGA_master I can generate an internal auto trigger. This trigger is sent to FPGA_slave thru certain connection.

On the computer connected with FPGA_slave, I run a C/C++ application and I wish to receive the external trigger from FPGA_master and use this external trigger to drive data acquisition on FPGA_slave.

In the C/C++ application, how do I specify to receive such external trigger?

More detailed info:

• The FPGAs are HawkEye-CL and the software SDK is Gidel's ProcFG;
• The input to FPGA_slave is thru VGA cable instead of thru Camera Link cable (CC pins).

Again, any specific help or general guidance would be greatly appreciated.

William

I suggest you are using the COM-Interface lines in the VGA / CL - lane?
If not, triggers usually are best kept as a forbidden character or a key embedded in the data stream.
What you need is a decoder / UART and/or a driver to provide an interface for you C-runtime access.