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Chapter 16 Interrupt (S12XINTV1)
MC9S12XDP512 Data Sheet, Rev. 2.21
Freescale Semiconductor
611
Figure 16-14. Interrupt Processing Example
16.5.3
Wake Up from Stop or Wait Mode
16.5.3.1
CPU Wake Up from Stop or Wait Mode
Every I bit maskable interrupt request which is congured to be handled by the CPU is capable of waking
the MCU from stop or wait mode. To determine whether an I bit maskable interrupts is qualied to wake
up the CPU or not, the same settings as in normal run mode are applied during stop or wait mode:
If the I bit in the CCR is set, all I bit maskable interrupts are masked from waking up the MCU.
An I bit maskable interrupt is ignored if it is congured to a priority level below or equal to the
current IPL in CCR.
I bit maskable interrupt requests which are congured to be handled by the XGATE are not capable
of waking up the CPU.
An XIRQ request can wake up the MCU from stop or wait mode at anytime, even if the X bit in CCR is set.
16.5.3.2
XGATE Wake Up from Stop or Wait Mode
Interrupt request channels which are congured to be handled by the XGATE are capable of waking up the
XGATE. Interrupt request channels handled by the XGATE do not affect the state of the CPU.
0
Reset
4
0
7
6
5
4
3
2
1
0
L4
7
0
4
L1 (Pending)
L7
L3 (Pending)
RTI
4
0
3
0
RTI
1
0
RTI
Stacked IPL
Processing Levels
IPL in CCR