PXR40RM Datasheet, PDF (1166/1434 Pages) Freescale Semiconductor, Inc – PXR40 Microcontroller

Decimation Filter
28.5.2.2.3 CPU Interrupt Handler
All sources of interrupts from the Decimation Filters A, B, C and D are routed to separate single vector
numbers. Each of the remaining Decimation Filters has a single interrupt vector for all interrupt sources.
Decimation Filter C uses vector numbers 467 to 469.
Set INTC vector number 468 to the address of Decimation Filter C output data interrupt handler.
Set the priority for the Decimation Filter and enable interrupts by lowering the processor priority.
When the interrupt occurs, if DECFILT_C_MSR[OBIF] = 1 then this indicates filter output data is
available.
In this case, read the DECFILT_C_OB, then clear the output data interrupt by writing
DECFILT_C_MSR[OBIC] = 1.
Note that DECFILT_C_MSR[IBIF] should also be set when the output data interrupt occurs, as a result of
the previous write to the input data register, so it should be cleared also by writing
DECFILT_C_MSR[IBIC] = 1. The CPU can now also write a new input value to the DECFILT_C_IB
register.
The error flags OVF, OVR and IVR should also be checked at this point, and clear if set, and remedial
action taken, if desired by the application.
28-52
PXR40 Microcontroller Reference Manual, Rev. 1
Freescale Semiconductor