From the Barco case on PLLs it appears that the PLLs in the accused infringers microprocessors contain a ring oscillator which generates the initial clock signal. The PLL itself is timed by an external off chip reference crystal BUT NOT THE RING OSCILLATOR ITSELF located on chip. I think this is the confusion the accused infringers are trying to take advantage of. Microprocessors that infringe on the 336 can have an external off chip crystal or timing device it just cannot be the initial source for the clocking of the CPU. The on chip ring oscillator is that source. The ITC judge noted in his denial of summary judgment did say:

"the administrative law judge finds that the portions of Dr. Oklobdjiza's initial report providing a general description of PLLs raise a material issue as to whether the oscillators in the PLLs of the Respondants accused products generate a clock signal without a control signal, external crystal clock or clock generator. (see Oklobdjiza Rep. at 76-77.)"

The info below is TPL/PTSC response to the Barco MSJ in the NDOC case:

"The Barco Lighting Console Hog iPC contains an Agere 100404226 microprocessor.7 TPL’s Infringement Contentions included an Alliacense Product Report and Alliacense Teardown Report, with a photograph showing that the Agere 1004040226 microprocessor is connected to an external crystal. See Oklobdzija Decl., 23. This is evident because the photograph shows the device Dr. Oklobdzija identified as a crystal is stamped with the name “TXC,” a company that makes and sells crystals and oscillators, and “30,000,” which indicates that the crystal oscillates at 30 MHz. Id. In addition, based on the photograph, the packaging of the TXC device resembles a crystal, and TXC’s website contains photographs of crystals with identical packaging. Id., 24. The crystal is an external timing reference for the PLL, and as discussed previously, a VCO is an indispensable and necessary building block of the PLL. Id., 25. Because of the VCO’s relationship to parameters, such as voltage and temperature (among others), the VCO is a variable speed oscillator by its nature. Id. As with the AMCC chip, a VCO is most commonly implemented using a ring oscillator. Oklobdzija Decl., 25. Variability of the VCO due to voltage and other parameters is described in Ian Young’s fundamental paper about PLLs. Id. The art of PLL and VCO design, including its variability based on parameters of temperature, voltage, and process, has not changed fundamentally since Young’s article was published in 1992. Id. It is well known to one having ordinary skill in the art that the variable-speed VCO, implemented using a ring oscillator, is the element generating the clocking signal used to time the CPU."

This was a post by Neverending on another board.