Chapter 29 Wakeup Unit (WKPU)
MPC5602P Microcontroller Reference Manual, Rev. 4
Freescale Semiconductor
787
to recognize interrupts with an active rising edge, an active falling edge or both edges being active. A
setting of having both edge events disabled results in no interrupt being detected and should not be
configured.
The active NMI edge is controlled by the user through the configuration of the NREE and NFEE bits.
NOTE
After reset, NREE and NFEE are set to 0, therefore the NMI functionality is
disabled after reset and must be enabled explicitly by software.
Once the pad’s NMI functionality has been enabled, the pad cannot be reconfigured in the IOMUX to
override or disable the NMI.
The NMI destination interrupt is controlled by the user through the configuration of the NDSS bits. See
for details.
An NMI supports a status flag and an overrun flag, which are located in the NSR register (see
).
This register is a clear-by-write-1 register type, preventing inadvertent overwriting of other flags in the
same register. The status flag is set whenever an NMI event is detected. The overrun flag is set whenever
an NMI event is detected and the status flag is set (that is, has not yet been cleared).
NOTE
The overrun flag is cleared by writing a 1 to the appropriate overrun bit in
the NSR register. If the status bit is cleared and the overrun bit is still set, the
pending interrupt will not be cleared.