Freescale Semiconductor MPC5553, Reference Manual

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MPC5553/MPC5554 Microcontroller Reference Manual, Rev. 5
Freescale Semiconductor 10-43
load INTC_IACKR
if stacked PRI values are not depleted, branch to push_lifo
NOTE
Reading the INTC_IACKR acknowledges the interrupt request to the
processor and updates the INTC_CPR[PRI] with the priority of the
preempting interrupt request. If the processor recognition of interrupts is
disabled during the LIFO restoration, interrupt requests to the processor can
go undetected. However, because the peripheral or software settable
interrupt requests are not cleared, the peripheral interrupt request to the
processor re-asserts when INTC_CPR[PRI] is lower than the priorities of
those peripheral or software settable interrupt requests.
10.6 Revision History
Table 10-12. Changes to MPC5553/5554 RM for Rev. 4.0 Release
Description of Change
• Added a note to the Block Diagram: “The total number of interrupt sources in the MPC5554 is 308, which includes 278
peripheral, 22 reserved sources, and 8 software sources.”
• Changed the NOTE at the end of Section 10.4.1:
From: “In this case, the interrupt vector will correspond...”
To: “If the interrupt request to the processor does assert or does remain asserted, the interrupt vector will correspond...”