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Decimation Filter
MPC5644A Microcontroller Reference Manual, Rev. 6
Freescale Semiconductor
1171
Chapter 26
Decimation Filter
26.1
Information specific to this device
This section presents device-specific parameterization and customization information not specifically
referenced in the remainder of this chapter.
26.1.1
Device-specific features
Two Decimation Filter modules are implemented in MPC5644A. The Decimation filter is used to decimate
conversion results from the eQADC block. A dedicated slave-bus interface provides bidirectional
communication between the eQADC and Decimation filters. Another slave-bus interface is also provided
for setting up the filter parameters and configuration registers. The Decimation Filter receives conversion
results generated by the eQADC block. These results can be generated from eight different ADC setup
configurations which are identified by an specific eQADC Control address within a conversion command.
Conversion commands with Register Address set to zero use the standard configuration setup. The
samples generated by the standard configuration setup are sent to one of the local eQADC RFIFO buffers.
The samples generated by the Alternate Configurations, with address from 1 to 6, can be sent to the internal
RFIFO or to the eQADC dedicated slave-bus interface to communicate with the external Decimation Filter
IP block or any other block that can communicate with this interface. A bit field in the Alternate
Configuration Control Register selects the Internal RFIFO or this slave-bus interface as the destination for
the conversion result.
26.1.2
Device-specific parameters
MDIS_DEFAULT resets MDIS bit in Decimation Filter Module Configuration Register to 0.
26.2
Introduction
26.2.1
Overview
The decimation filter is a dedicated hardware block, designed to decimate fixed point sample conversion
results, generated by master block, usually an eQADC. A dedicated parallel side interface (PSI) provides
bi-directional communication between the master block and the filter. A second interface is provided for
use by the CPU, allowing setup of the filter parameters and read/write of the configuration registers.
The Decimation Filter receives data samples from the master block (eQADC) in the PSI RX sub-block.
Each sample arrives at the decimation filter with an identifier tag and associated commands. The input
information is decoded by the PSI RX and control logic sub-blocks. When receiving a filtering command,
Table 26-1. Decimation Filter Parameters for MPC5644A
Parameter Name
Description
Value
MDIS_DEFAULT
DECFILTER_MCR[31], MDIS reset state
0
Summary of Contents for MPC5644A
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Page 52: ...Introduction MPC5644A Microcontroller Reference Manual Rev 6 52 Freescale Semiconductor...
Page 56: ...Memory Map MPC5644A Microcontroller Reference Manual Rev 6 56 Freescale Semiconductor...
Page 1228: ...Decimation Filter MPC5644A Microcontroller Reference Manual Rev 6 1228 Freescale Semiconductor...
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