Chapter 4 Port Integration Module (S12XDP512PIMV2)
MC9S12XDP512 Data Sheet, Rev. 2.11
266 Freescale Semiconductor
4.4.3 Pin Interrupts
Ports P, H and J offer pin interrupt capability. The interrupt enable as well as the sensitivity to rising or
falling edges can be individually configured on per-pin basis. All bits/pins in a port share the same
interrupt vector. Interrupts can be used with the pins configured as inputs or outputs.
An interrupt is generated when a bit in the port interrupt flag register and its corresponding port interrupt
enable bit are both set. The pin interrupt feature is also capable to wake up the CPU when it is in STOP or
WAIT mode.
A digital filter on each pin prevents pulses (Figure 4-78) shorter than a specified time from generating an
interrupt. The minimum time varies over process conditions, temperature and voltage (Figure 4-77 and
Table 4-69).
Figure 4-77. Interrupt Glitch Filter on Port P, H, and J (PPS = 0)
Figure 4-78. Pulse Illustration
Table 4-69. Pulse Detection Criteria
Pulse Mode
STOP Unit STOP1
1These values include the spread of the oscillator frequency over temperature,
voltage and process.
Ignored tpulse 3 Bus clocks tpulse tpign
Uncertain 3 < tpulse < 4 Bus clocks tpign < tpulse < tpval
Valid tpulse 4 Bus clocks tpulse tpval
Glitch, filtered out, no interrupt flag set
Valid pulse, interrupt flag set
tpign
tpval
uncertain
tpulse