Seems to be an Intel motherboard clock synthesizer, but the only available datasheet is from SiLabs. Packaging and block diagram of the SiLabs datasheet are consistent with this device.
Looks like the result of corporate mergers and spinoffs: The chip was designed by Cypress in 2000, who sold their clocking products division to SpectraLinear in 2006, who were in turn acquired by SiLabs in 2011 http://www.eetimes.com/document.asp?doc_id=1258470