MPC5604B/C Microcontroller Reference Manual, Rev. 8
Freescale Semiconductor 275
The INTC_CPR masks any peripheral or software configurable interrupt request set at the same or lower
priority as the current value of the INTC_CPR[PRI] field from generating an interrupt request to the
processor. When the INTC interrupt acknowledge register (INTC_IACKR) is read in software vector
mode or the interrupt acknowledge signal from the processor is asserted in hardware vector mode, the
value of PRI is pushed onto the LIFO, and PRI is updated with the priority of the preempting interrupt
request. When the INTC end-of-interrupt register (INTC_EOIR) is written, the LIFO is popped into the
INTC_CPR’s PRI field.
The masking priority can be raised or lowered by writing to the PRI field, supporting the PCP. Refer to
Section 16.7.5, “Priority ceiling protocol.
NOTE
A store to modify the PRI field which closely precedes or follows an access
to a shared resource can result in a non-coherent access to that resource.
Refer to Section 16.7.5.2, “Ensuring coherency for example code to ensure
coherency.
Table 16-5. PRI values
PRI Meaning
1111 Priority 15—highest priority
1110 Priority 14
1101 Priority 13
1100 Priority 12
1011 Priority 11
1010 Priority 10
1001 Priority 9
1000 Priority 8
0111 Priority 7
0110 Priority 6
0101 Priority 5
0100 Priority 4
0011 Priority 3
0010 Priority 2
0001 Priority 1
0000 Priority 0—lowest priority
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