Motorola MPC823e - Page 522

Communication Processor Module
16-68 MPC823e REFERENCE MANUAL MOTOROLA
DSP
COMMUNICATION
16
PROCESSOR MODULE
16.3.4.10.1 Coefficients and Sample Data Buffers. The coefficients vector occupies k
pairs of 16-bit half-words (real and imaginary components) in memory and C(0) is stored in
the first location. The sample input buffer is a cyclic buffer containing M+1 bytes. Each
sample is a pair of 16-bit half-words (real and imaginary components) and the new sample
is stored in the address that follows the previous sample.
16.3.4.10.2 LMS2 Function Descriptor. The LMS2 function descriptor bit table is
described below.
COEFFICIENTS INPUT SAMPLES
imag{C(0)} *
real{C(0)} *
imag{C(1)} *
real{C(1)} imag{X(n-k+1)}
* real{X(n-k+1)}
**
imag{C(k-1)} *
real{C(k-1)} imag{X(n-2)}
real{X(n-2)}
imag{X(n-1)}
real{X(n-1)}
imag{X(n)}
real{X(n)}
2K bytes M + 1 bytes
Figure 16-31. LMS2 Coefficients and Sample Data Buffers
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
OFFSET + 0
S RES W I Z RES INDEX RES OPCODE
OFFSET + 2
RESERVED
OFFSET + 4
K
OFFSET + 6
CBASE
OFFSET + 8
M
OFFSET + A
XPTR
OFFSET + C
EPTR
OFFSET + E
RESERVED