All clock sources that operate with external components have a built-in fail-safe mechanism that automatically switches to the relevant backup source, thereby ensuring that spurious or unstable clocks never affect the device behavior. Table 6-45 lists the different types of clock source faults and the corresponding fail-safe clocks.
|Fault Type||Fail-Safe Clock|
|LFXT oscillator fault||REFO clock|
|HFXT oscillator fault||SYSOSC clock|
|DCO external resistor open circuit fault||DCO clock in internal resistor mode|