Motorola MPC860 PowerQUICC User Manual page 927

X(n)
{Complex}
T
T
T
36.11.3.1 FIR3 CoefÞcient, Input, and Output Buffers
The coefÞcient vector occupies K pairs of 16-bit entries (real and imaginary components)
in memory and C(0) is stored in the Þrst location. The input sample buffer is a circular
buffer containing (M+1) bytes and each input sample is two 16-bit entries (real and
imaginary components). The next sample is stored in the address that follows the previous
sample. The output buffer is a circular buffer that contains (N+1) bytes and each output is
two 16-bit entries (real and imaginary components). The next output is stored in the address
that follows the previous output. See Table 36-11.
Table 36-11. FIR3 Coefficient, Input, and Output Buffers
CoefÞcients
imaginary{C(0)}
real{C(0)}
imaginary{C(1)}
real{C(1)}
*
*
imaginary{C(k-1)}
real{C(k-1)}
MOTOROLA
C(0)
{Complex}
å
C(1)
C(2)
C(kÐ1)
Figure 36-14. FIR3 Function
Input Samples
*
*
imaginary {x(n-k+1)}
real {x(n-k+1)}
*
*
imaginary {x(n-2)}
real{x(n-2)}
imaginary{x(n-1)}
real{x(n-1)}
imaginary{x(n)}
real{x(n)}
Chapter 36. Digital Signal Processing
Part V. The Communications Processor Module
Y(n)
{Real or Complex}
ì
k 1
Ð
ï
å
Y n ( )
=
í
Real
ï
p =
î
k 1
Ð
å
Y n ( )
=
OR
p = 0
Complex Output, FD[X]=1
*
*
imaginary{Y(n-k+1)}
real{Y(n-k+1)}
*
*
imaginary{Y(n-2)}
real{Y(n-2)}
imaginary{Y(n-1)}
real{Y(n-1)}
imaginary{Y(n)}
real{Y(n)}
ü
ï
C p ( )X n p ( )
ý
Ð
ï
0
þ
C p ( )X n p ( )
Ð
Real Output, FD[X]=0
*
*
Y(n-k+1)
*
*
Y(n-2)
Y(n-1)
Y(n)
36-13