PXR40RM Datasheet, PDF (1148/1434 Pages) Freescale Semiconductor, Inc – PXR40 Microcontroller

Decimation Filter
28.3.12.3 Integrator Interrupt and DMA Requests
An interrupt or DMA request can be asserted when an integrator output is ready to be read or an overflow
or error condition occurs in either the integrator sum or count values. Integrator interrupt requests are
enabled by the DECFILT_x_MCR[SDIE] bit, and flagged in the DECFILT_x_MXSR[SDF] bit. Integrator
DMA requests are enabled by the DECFILT_x_MXCR[SDMAE] bit.
28.3.13 Integrator
The decimation filter output result may be optionally routed to a dedicated hardware integrator. The
integrator may be operated in a windowed mode, controlled by signals routed internally from eTPU2
channels, or operated in a continuous mode. Additionally, the integrator output may be configured to
saturate at the maximum value of the supported range, or permitted to continue integration. Figure 28-17
shows the high level data flows and controls for the integrator. The RFIFO and Output Buffer data paths
are shown in this figure to highlight that they are independent of the integrator. Note however that the
Output Buffer shares a DMA and Interrupt request with the Integrator output value, FINTVAL
(DECFILTER_FINTVAL).
Filter
eTPU2
Channel
eTPU2
Channel
Decimator
Pause Reset Start Output
Integrator & Sample Counter
Integration Sample
Value
Count
RFIFO
DMA or
Interrupt
Output Buffer
DMA or
Interrupt
FINTVAL CINTVAL
Figure 28-17. Integrator Data and Control
FINTCNT CINTCNT
28.3.13.1 Integrator Inputs
The integrator input can come either directly from the filter output or from the decimator output, selected
by the DECFILTER_MXCR[SISEL] (see Section 28.2.2.3, Decimation Filter Module Extended
Configuration Register (DECFILT_x_MXCR)“). Prior to integration a hardware option, controlled by
DECFILTER_MXCR[SSIG], is provided to convert the input to its absolute value.
NOTE
The integrator accumulates input samples when bypass is selected in the
filter.
28-34
PXR40 Microcontroller Reference Manual, Rev. 1
Freescale Semiconductor