Can PCI-6534 multitask unstrobed and pattern I/O functions in separate halves of the same signal group?

[bob.barr]

If so, how does this work - byte level addressing on the PCI bus? If not, what would a user need to do to avoid losing the second half the signal group for subset individual direction control?

[Geneva L.]

Yes, the 653x boards allow you to use the leftover data lines for unstrobed IO. For instance, let's say you want to do pattern generation on the 8 lines of port 0 and burst mode handshaking on the 8 lines of port 2, since you have 2 groups of strobed operations available on the board. These use the two sets of control lines (REQ, ACK, etc.). You can still do unstrobed IO on the remaining lines, port 1 and port 3. Remember that unstrobed IO is software controlled, so you would call the functions to immediately read from or write to those lines.

You can try this with the examples. In LabVIEW, open up the Write to 1 Dig Port example and set it to digital channel 1. Then, open up the Continuous Pattern Input example, and set the port list to 0. You'll be abl
e to run both examples simultaneously. The examples are in the LabVIEW >> Examples >> Daq >> Digital >> 653x directory.

With the NI-DAQ function calls in Measurement Studio, you can open up the DOdoubleBufPatternGen653x example, setting port to 0, group size to 1. Then, open up the DOOnePort with port set to 1. You can run them simultaneously. The examples are in the NI-DAQ >> Examples >> DI or DO directory.

You can find further information in the 653x User Manual at the http://www.ni.com/manuals page.

Regards,
Geneva L.
Applications Engineer
National Instruments
http://www.ni.com/ask

[Joe P.]

This answer not only answers the question asked but the next several questions that would normally follow as well. As always, Geneva is correct and concise. Keep up the good work!