Programming a New Output Frequency on the Si570 Clock Chip

Updated Oct 29, 2018

Reported In


  • NI-6589

Issue Details

I have an NI 6587 or NI 6589 Digital I/O Adapter Module. I need to set a new frequency for the adapter module's onboard clock. I see that the adapter module uses the Si570 clock chip, so how do I program it to set a new output frequency.


There is a VI available in several examples for the NI 6587 and NI 6589. This VI takes two inputs, the desired new output frequency and the Xtal (crystal) frequency. The VI translates this information into the register values that need to be written to the Si570. 

The VI is called Clock Frequency, and it can be found in several examples for the NI 6587 and NI 6589 if you have the FlexRIO drive installed.

Additional Information

For additional information on the Si570, refer to the chip's datasheet from Silicon Labs, which is included in the Related Links section. 


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