Information

34.4.5 Interrupts
PDB can generate two interrupts, PDB interrupt and PDB sequence error interrupt. The
following table summarizes the interrupts.
Table 34-37. PDB Interrupt Summary
Interrupt Flags Enable Bit
PDB Interrupt SC[PDBIF] SC[PDBIE] = 1 and
SC[DMAEN] = 0
PDB Sequence Error Interrupt CHnS[ERRm] SC[PDBEIE] = 1
34.4.6 DMA
If SC[DMAEN] is set, PDB can generate DMA transfer request when SC[PDBIF] is set.
When DMA is enabled, the PDB interrupt will not be issued.
34.5 Application Information
34.5.1 Impact of Using the Prescaler and Multiplication Factor on
Timing Resolution
Use of prescaler and multiplication factor greater than 1 limits the count/delay accuracy
in terms of peripheral clock cycles (to the modulus of the prescaler X multiplication
factor). If the multiplication factor is set to 1 and the prescaler is set to 2 then the only
values of total peripheral clocks that can be detected are even values; if prescaler is set to
4 then the only values of total peripheral clocks that can be decoded as detected are
mod(4) and so forth. If the applications need a really long delay value and use 128, then
the resolution would be limited to 128 peripheral clock cycles.
Therefore, use the lowest possible prescaler and multiplication factor for a given
application.
Application Information
K20 Sub-Family Reference Manual, Rev. 2, Feb 2012
686 Freescale Semiconductor, Inc.