Table of Contents
Advertisement
Enhanced Filter Coprocessor
FDM by the corresponding coefficient, A, stored in the FCM; accumulates the multiplication
results; adds the input, w(n), from the FDIR (which is optionally not scaled by S, depending on
the FACR[FISL] bit setting); places the accumulation result, y(n), in the FDOR; and saves the
output while shifting the previous outputs down in the FDM. This is done for each sample input
to the FDIR. To process a complete IIR filter, a FIR filter type session followed by an IIR filter
type session is needed.
FDM
y(n – 1)
y(n – 2)
y(n – 3)
y(n – N)
The IIR filter type only operates in Real mode. Thus, the FCSR[FOM] bits are ignored when the
IIR filter type is in use. Real mode performs IIR type filtering with real data. One sample, the real
input, is written to the FDIR, and the EFCOP processes the data. Then one sample, the real
output, is read from the FDOR.
The default operation is single-channel, but the user can also select the Multi-channel Mode
option. Multichannel mode for IIR filter type works exactly the same as it does for FIR filter
type, as explained in Section 10.3.3.2.3, Multichannel Mode Option, on page 10-11. The
Coefficient Update, Adaptive mode, and Decimation options are not available with the IIR filter
type.
10.3.5 EFCOP Data Transfer Examples
This section describes how to transfer data to and from the EFCOP using an FIR filter
configuration. Here, we provide background information to help you understand the examples in
Section 10.3.6, EFCOP Operation Examples, on page 10-14. The examples employ the
following notations:
D(n): Data sample at time n
H(n): Filter coefficient at time n
10-12
FCM
A
0
A
1
A
2
A
N
Figure 10-5. IIR Filter Type Processing
DSP56311 Reference Manual, Rev. 2
FDOR
FDIR
Freescale Semiconductor
Advertisement
Table of Contents
