mpc823rg Freescale Semiconductor, Inc, mpc823rg Datasheet - Page 509

• Manufacturer Part Number: mpc823rg
• Description: Mpc823 Powerquicc Integrated Communications Processor For Portable Systems
• Manufacturer: Freescale Semiconductor, Inc

16.3.4.5.3 FIR6 Parameter Packet. The FIR6 parameter packet is composed of seven
16-bit half-words and described in the table below.
16.3.4.6 IIR–REAL C, REAL X, REAL Y. The IIR function implements a basic BIQUAD IIR
filter with six real coefficients, real input samples, and real outputs. The input data is in a
circular buffer with size M+1 and the output data is in a circular buffer with size N+1. Several
stages of the BIQUAD filter can be cascaded by specifying an iteration count greater than
one and concatenating the filter coefficients into one vector.
16.3.4.6.1 Coefficients and Sample Data Buffers. The coefficients vector occupies six
16-bit half-words in memory and C(0) is stored in the first location. C(1) is only used in the
last stage of a cascaded IIR filter. The sample input buffer is a cyclic buffer that contains
M+1 bytes. Each sample is a 16-bit half-word and the new sample is stored in the address
that follows the previous sample. The output buffer is a cyclic buffer that contains N+1 bytes
and the new output is stored in the address that follows the previous one.
Half-word 1
Half-word 2
Half-word 3
Half-word 4
Half-word 5
Half-word 6
Half-word 7
ADDRESS
{REAL}
X(N)
{REAL}
C(0)
CBASE
XYPTR
NAME
RES
M
K
N
I
Figure 16-22. IIR Implementation Example
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Table 16-12. FIR6 Parameter Packet
Number of Iterations-1 (0 = one iteration)
Number of TAPs-1. The number of taps must be a multiple of 2.
Filter Coefficients Vector Base Address Pointer
Samples Buffer Size-1. The minimum sample buffer size is 4(2 samples).
Pointer to a structure composed of the input sample data pointer and the output
buffer pointer
Output Buffer Size-1. The minimum output buffer size is 8 (2 outputs).
Reserved
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C(3)
C(2)
T
T
DESCRIPTION
C(5)
C(4)
Communication Processor Module
C(1)
{REAL}
Y(N)
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