Accessing and updating the parameters for the PLL firmware You will have to have previously installed the CAEN utility CAENUpgrader package using the default make/install options. Only the command line program cvUpgrade is used. This is usually found in /usr/local/bin/ The directories /etc/CAENUpgrader/PLL & /etc/CAENUpgrader/params are also required. These are also used by the CAEN Firmware Update page.