There is a note in the STR71x Reference Manual ( PRCCU part ) saying that
if this facter is diffrent from 0 , the PRCCU register mainly the CFR is
not accessible anymore. This is due to the fact that the PRCCU block is always clocked by the RCLK clock which is at this case a multiple of the MCLK ( Core & memory) Clock
Retrieving data ...