Decimation Filter
Freescale Semiconductor
28-29
PXR40 Microcontroller Reference Manual, Rev. 1
28.3.7
Soft Reset Command
The Soft Reset command is requested through the self negated bit SRES of the DECFILT_x_MCR register
and provides the CPU with the capability to initialize the Decimation Filter. After the software reset is
issued, all internal Filter TAP registers, the decimation counter, and the state machine are put in to the reset
state. The status register DECFILT_x_MSR is also cleared. The Coefficient registers are not affected by
the Soft Reset. If the filter is currently processing data (the MAC is active and
DECFILT_x_MSR[BSY]=1), the processing is aborted. In addition, any pending output data transfer to
the eQADC RFIFO is terminated. The software reset command has precedence over all other register
control bits except the module disable bit. The DECFILT_x_MSR[BSY] is set on the detection of the
assertion of the DECFILT_x_MCR[SRES] bit, and remains set until the reset procedure is complete.
The configuration register DECFILT_x_MCR is also not affected by a soft reset, except for the
self-negation of the SRES bit.
When in debug or freeze mode, the soft reset is executed but the filter remains in debug or freeze mode.
28.3.8
Freeze Mode
The freeze mode operation is entered using the FREN and FRZ bits in the DECFILT_x_MCR register, or
when the entire SoC enters debug mode.
It is not possible to enter freeze mode when the Decimation Filter is disabled.
In case of a freeze mode request during the processing of an input sample, the current processing is finished
and then the Decimation Filter block enters freeze mode.
Access to all memory mapped registers in the Decimation Filter remains active in freeze mode.
28.3.9
Filter Implementation
contains eight taps which may be configured as an IIR or FIR
filter. Multiplexer A controls the
bypass
filter path and multiplexer B controls/selects the filter mode of
operation, to either IIR mode or FIR mode. The selection is controlled by the FTYPE[1:0] bits in the Filter
Module Configuration register. The order of the filter can be controlled by setting the appropriate filter
coefficients to zero. The IIR can be up to 4rd order and the FIR up to 8th order.
Summary of Contents for PXR4030
Page 1: ...PXR40 Microcontroller Reference Manual Devices Supported PXR4030 PXR4040 PXR40RM Rev 1 06 2011...
Page 30: ...PXR40 Microcontroller Reference Manual Rev 1 Freescale Semiconductor xxx...
Page 40: ...PXR40 Microcontroller Reference Manual Rev 1 xl Freescale Semiconductor...
Page 66: ...Memory Map PXR40 Microcontroller Reference Manual Rev 1 2 4 Freescale Semiconductor...
Page 120: ...Signal Descriptions 3 54 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
Page 860: ...FlexCAN Module 24 50 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...
Page 1167: ...Decimation Filter Freescale Semiconductor 28 53 PXR40 Microcontroller Reference Manual Rev 1...
Page 1168: ...Decimation Filter 28 54 Freescale Semiconductor PXR40 Microcontroller Reference Manual Rev 1...