How can I create a register in the PXI FPGA to emulate the PC parallel port via Labview and use a C program compiled in Labwindows?

[dbanner]

I have a PXI chassis with a PXI-7813R FPGA that I am configuring with Labview 8 FPGA module.  I have a "C" based program that currently uses a parallel port on a PC to control hardware via a data file to program a JTAG component.  How can I create a register in the FPGA to emulate the PC parallel via Labview and still use the C program compiled in Labwindows?  I need the "bit-banging" code to run as fast as possible so I would like direct PXI register access.

Message Edited by dbanner on 02-22-2006 07:34 PM

[Bassett_Hound]

dbanner,

If I understand your application correctly, it sounds like to interface your C program and your PXI-7831R you would just need to configure a set of Digital Inputs and Digital Outputs on the FPGA device that would correspond to the Pins used for Parallel Communication.  The data coming in on the FPGA lines could then be processed in the 7831R to emulate your hardware.  The 7831R gets down to 25ns timing so speed should not be to much of an issue.

sbassett

[dbanner]

I can currently control the FPGA pins with Labview VI's but I am looking for a way for Labwindows to interface with the Labview FPGA pins for reading and writing signals.  I am looking for a way to read/write registers directly with Labwindows after the Labview VI configures the FPGA. 

Can Labwindows use the "shared variables" in a Labview project?

[Bassett_Hound]

dbanner,

You can definitely acess the shared variables in a LabVIEW Project with CVI/LabWindows.  To do this you will have to use the DataSocket API.  I have attached a link below that will discuss this in more detail.  Look for the section on programatic acess.

Using the LabVIEW Shared Variable

Steven