How to do a digital output triggered by the falling edge of a clock?

Hello !
I would like to do a digital output (on a given line of a pci 6602 card) triggered by the falling edge of a clock.
More precisely, a pulse train is generated. I have to output each bit of a variable (first, the LSB ; then, the others bits, until the MSB), each bit being transfered on a falling edge of the pulse train. How could I do that, please ?
Thank you for helping me.
Julian.

see the following link (other forum same subject)
http://forums.ni.com/ni/board/message?board.id=40&message.id=1634

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