Motorola MPC823e - Page 521

Communication Processor Module
MOTOROLA MPC823e REFERENCE MANUAL 16-67
DSP
COMMUNICATION
16
PROCESSOR MODULE
16.3.4.9.3 LMS1 Parameter Packet. The LMS1 parameter packet is composed of seven
16-bit half-words and is described in the table below.
16.3.4.9.4 Application Example. The LMS1 is used in the echo cancellation update.
16.3.4.10 LMS2–COMPLEX COEFFICIENTS, COMPLEX SAMPLES, AND
REAL/COMPLEX SCALAR. The LMS2 function implements a basic FIR filter coefficients
update and the sample pointer is incremented by two, which is required for fractionally
spaced equalizer updates. The coefficients and input samples are complex numbers, but
the scalar is a real or complex number.
Table 16-16. LMS1 Parameter Packet
ADDRESS NAME DESCRIPTION
Half-word 1 RES Reserved
Half-word 2 K Number of Taps-1.
Half-word 3 CBASE Filter Coefficients Vector Base Address Pointer
Half-word 4 M Samples Buffer Size-1. The minimum sample buffer size is 8 (2 samples).
Half-word 5 XYPTR Pointer to New Sample Data Pointer
Half-word 6 EPTR Pointer to Scalar
Half-word 7 RES Reserved
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
OFFSET + 0
S 0 W I Z 0 INDEX 0 0 0 01010
OFFSET + 2
I=1 (ONE ITERATION)
Figure 16-30. LMS2 Implementation Example
C
n1+
i
C
n
i
EX
ni
–
×
+=