User`s manual

Software Manual • EKF Intelligent I/O Controller Family On CompactPCI
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EKF Elektronik GmbH * Philipp-Reis-Str. 4 * D-59065 HAMM (Germany)
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If the board isn’t still found after removing this jumper, check whether your system CPU
board supports the so-called spread spectrum clocks on the
CompactPCI
bus. The clock in
this case is modulated by another low frequent clock (typical 0.5% of the base clock) with the
advantage of an improved EMC behaviour.
Since the EKF Intelligent I/O Controller Family boards are equipped with a PLL based clock
buffer, the boards doesn’t work properly when fed with a spread spectrum clock. Thus it is
necessary to disable the clock spreading. Perhaps there exists a switch in the BIOS CMOS
setup to do so. Ask your system CPU manufacturer for details if there is any unclarity about
this issue.