12.3.8 Interrupts
| Interrupt Vector Name | Interrupt Source Name | Description | Condition |
|---|---|---|---|
| NMI | CFD | External crystal oscillator or clock source failure | The CFD flag in CLKCTRL.MCLKINTFLAGS is '1' and the INTTYPE bit
in CLKCTRL.MCLKINTCTRL is '1' |
| CLKCTRL | The CFD flag in CLKCTRL.MCLKINTFLAGS is '1' and the INTTYPE bit
in CLKCTRL.MCLKINTCTRL is '0' |
A Non-Maskable Interrupt (NMI) is enabled by writing a ‘1’ to the Interrupt
Type (INTTYPE) bit in the Interrupt Control (CLKCTRL.MCLKINTCTRL) register, but can only be
disabled with a System Reset. An NMI is generated when the CFD flag in the
CLKCTRL.MCLKINTFLAGS register is set and the INTTYPE bit in the CLKCTRL.MCLKINTCTRL register
is ‘1’. The NMI request remains active until a System Reset and cannot be
disabled. The Clock Failure Detect Enable (CFD) bit in the CLKCTRL.MCLKINTCTRL register is
write-protected when NMI is enabled.
An NMI can be triggered even if interrupts are not globally enabled.
A regular interrupt is enabled by writing a ‘1’ to the Clock Failure Detect
Enable (CFD) bit in the Interrupt Control (CLKCTRL.MCLKINTCTRL) register while the INTTYPE bit
is ‘0’ (default).
When the interrupt condition occurs the CFD flag in the Interrupt Flags (CLKCTRL.MCLKINTFLAGS) register is set.
An interrupt request is generated when the CFD interrupt source is enabled and the interrupt
flag is set. The interrupt request remains active until the interrupt flag is cleared. To
clear the interrupt flag, the CFD flag in the Interrupt Flags (CLKCTRL.MCLKINTFLAGS) register
must be written to ‘1’.