C167CS Datasheet, PDF (113/517 Pages) Infineon Technologies AG – 16-Bit Single-Chip Microcontroller

C167CS
Derivatives
Interrupt and Trap Functions
External Interrupts During Sleep Mode
During Sleep mode all peripheral clock signals are deactivated which also disables the
standard edge detection logic for the fast external interrupts. However, transitions on
these interrupt inputs must be recognized in order to initiate the wakeup. Therefore
during Sleep mode a special edge detection logic for the fast external interrupts (EXzIN)
is activated, which requires no clock signal (therefore also works in Sleep mode) and is
equipped with an analog noise filter. This filter suppresses spikes (generated by noise)
up to 10 ns. Input pulses with a duration of 100 ns minimum are recognized and
generate an interrupt request.
This filter delays the recognition of an external wakeup signal by approx. 100 ns, but the
spike suppression ensures safe and robust operation of the sleep/wakeup mechanism
in an active environment.
Input
Signal
10 ns
100 ns
Interrupt
Request
Rejected
Figure 5-6 Input Noise Filter Operation
Recognized
MCD04456
User’s Manual
5-30
V2.0, 2000-07